FileAdapter class | QSYS API Reference Guide

FileAdapter()

FileAdapter(AdgConnection)

FileAdapter(AdgConnection, String)

FileAdapter(AdgConnection, String, String)

FileAdapter(IFileObject, String)

FileAdapter(IFileObject)

void AddRecord(AdgDataSet ds)

void AddRecord(XmlReader xr, AdgDataSet ds)

void AddRecord(AdgDataSet ds, Char[] appIndicators)

void ChangeCurrent(AdgDataSet ds)

void ChangeRRN(AdgDataSet ds, long RRN)

void CheckKey(AdgKeyTable keyTable)

void Close()

AdgDataSet CreateDataSet()

void DeleteAllRecords()

void DeleteCurrent()

void DeleteKey(AdgKeyTable keyTable)

void DeleteRange(AdgKeyTable firstKey, RangeFirst rangeFirst, AdgKeyTable lastKey, RangeLast rangeLast)

void DeleteRRN(long RRN)

void Dispose()

void Dispose(bool isDisposing)

void Finalize()

void ForceEOD()

string GetFormatName(int i)

IPrintProperties GetPrintProperties(string format)

void Open(AdgDataSet ds)

void OpenNewAdgDataSet(AdgDataSet& ds)

void OpenSimpleQuery(AdgDataSet& ds, string queryFile, string query, String[] keyNames, KeyUsages[] keyFlags)

void ReadRandomKey(AdgDataSet ds, ReadRandomMode mode, LockRequest lr, AdgKeyTable keyTable)

void ReadRandomRRN(AdgDataSet ds, ReadRandomMode mode, LockRequest lr, long RRN)

void ReadRange(AdgDataSet ds, RangeMode mode, LockRequest lr, AdgKeyTable firstKey, RangeFirst rangeFirst, AdgKeyTable lastKey, RangeLast rangeLast)

void ReadSequential(AdgDataSet ds, ReadSequentialMode mode, LockRequest lr)

void ReadSequentialEqual(AdgDataSet ds, ReadEqualMode mode, LockRequest lr, AdgKeyTable keyTable)

void ReleaseCurrent()

void ReleaseRRN(LockRequest lr, long RRN)

void ResetFormat()

void ResetPrintAttr()

void ReuseRRN(AdgDataSet ds, long RRN)

void SeekKey(SeekMode mode, AdgKeyTable keyTable)

void SeekRange(RangeMode mode, AdgKeyTable firstKey, RangeFirst rangeFirst, AdgKeyTable lastKey, RangeLast rangeLast)

void SeekRRN(SeekMode mode, long RRN)

void SetFormat(string Format)

T ThrowIfNotOpen<T>(T openState)

  /* Opens a record which will spend no time waiting for a record
   * if that record is locked. */
  AdgConnection db = createAdgConnection("MyDatabaseName");
  FileAdapter dbFile = new FileAdapter(db, "*Libl/CMASTNEW", "CMMASTER");
  dbFile.AccessMode = AccessMode.Delete;
  dbFile.OpenAttributes.WaitForRecord = 0;
  AdgDataSet myDS = null;
  dbFile.OpenNewAdgDataSet(out myDS);

  /* We open the file in order to delete all of its records. */
  AdgConnection db = createAdgConnection("MyDatabaseName");
  FileAdapter dbFile = new FileAdapter(db, "*Libl/CMASTNEW", "CMMASTER");
  dbFile.AccessMode = AccessMode.Delete;
  /* Its generally good practice to make sure you have an exclusive lock
   * on a file that you are deleting all of the records from, but some
   * databases do not require it. */
  dbFile.OpenAttributes.ShareTypes = ShareTypes.Exclusive;
  AdgDataSet myDS = null;

  try
  {
      dbFile.Open(myDS);
      dbFile.DeleteAllRecords();
  }
  catch(dgException dgEx)
  {
      db.Close();
      if (dgEx.Error == dgErrorNumber.dgEmBUSYOBJ)
      {
          MessageBox.Show("Couldn't open the file for exclusive access.", "Error opening file.");
          //Exit routine or procedure here to avoid preceding file operations.
      }
      else 
          throw dgEx;
  }
  dbFile.DeleteAllRecords();

  dbFile.Close();
  db.Close();

  AdgConnection db = createAdgConnection("MyDatabaseName");
  FileAdapter dbFile = new FileAdapter(db, "*Libl/CMASTNEWL1", "CMMASTERL1");
  dbFile.AccessMode = AccessMode.Read;

  /* Automatically calculates the best blocking factor. */
  dbFile.OpenAttributes.BlockingFactor = FileOpenAttr.OptimalBlockingFactor;
  AdgDataSet ds = null;
  dbFile.OpenNewAdgDataSet(out ds);

  AdgConnection db = createAdgConnection("MyDatabaseName"); 
  FileAdapter dbFile = new FileAdapter(db, "*Libl/CMASTNEWL1", "CMMASTERL1"); 
  dbFile.AccessMode = AccessMode.Read; /* Omits record blocking feature. */
  dbFile.OpenAttributes.BlockingFactor = FileOpenAttr.OmitBlocking;
  AdgDataSet ds = null;
  dbFile.OpenNewAdgDataSet(out ds);

  /* Using the FileLocks property of a FileAdapter's OpenAttributes,
   * you can set file locking to manual, which allows you to lock more
   * than one record at a time. Note that manual file locking
   * is database dependent- for instance, it will work with a Acceler8
   * database but not with an IBM i. */
  AdgConnection db = createAdgConnection("MyDatabaseName");
  FileAdapter dbFile = new FileAdapter(db, "*Libl/CMASTNEWL1", "CMMASTERL1");
  dbFile.OpenAttributes.FileLocks = FileLocks.Manual;
  dbFile.AccessMode = AccessMode.RWCD;

  AdgDataSet myDS = null;
  dbFile.OpenNewAdgDataSet(out myDS);
  AdgKeyTable keyTbl = myDS.NewKeyTable("RCMMASTL1");

  /* In the code below, we read records for customer numbers
   * 400 - 800. When it ends, we will still have locks on customer numbers
   * 500 and 700. */
  try
  {
      /* Read customer number 400 but don't lock it. */
      keyTbl.Row["CMCUSTNO"] = 400;
      dbFile.ReadRandomKey(myDS, ReadRandomMode.Equal, LockRequest.NoLock, keyTbl);

      /* Read customer number 500 and lock it. */
      keyTbl.Row["CMCUSTNO"] = 500;
      dbFile.ReadRandomKey(myDS, ReadRandomMode.Equal, LockRequest.Read, keyTbl);

      /* Read customer number 600 and lock it. */
      dbFile.ReadSequential(myDS, ReadSequentialMode.Next, LockRequest.Read);

      /* Read customer number 700 and lock it. */
      dbFile.ReadSequential(myDS, ReadSequentialMode.Next, LockRequest.Read);

      /* Read customer number 800 without locking it. */
      dbFile.ReadSequential(myDS, ReadSequentialMode.Next, LockRequest.NoLock);

      /* Unlock customer number 600. */
      keyTbl.Row["CMCUSTNO"] = 600;
      dbFile.ReadRandomKey(myDS, ReadRandomMode.Equal, LockRequest.NoLock, keyTbl);
      dbFile.ReleaseCurrent();

  }
  catch(dgException dgEx)
  { 
      MessageBox.Show("Couldn't find one or more records. " + dgEx.Message,
          dgEx.Error.ToString());
  }

  dbFile.Close(); /* Release all locks. */
  db.Close();

  AdgConnection db = createAdgConnection("MyDatabaseName");
  FileAdapter dbFile = new FileAdapter(db, "*Libl/CMASTNEWL1", "CMMASTERL1");
  dbFile.AccessMode = AccessMode.Read;
  AdgDataSet myDS = null;

  int refreshInterval = 10; //Used so we don't slow down refreshing too much...
  dbFile.OpenAttributes.BlockingFactor = refreshInterval;
  dbFile.OpenNewAdgDataSet(out myDS);

    /* Here, we read every record until end of file is reached.
    * Because this is an fairly long process, we set up a progress bar
    * to keep the user from being discouraged. We set its Maximum
    * value to the number of records in the file, which is found
    * using FileAdapter's RecordCount property, divided by
    * our refreshInterval. */
  int recordsReadSinceLastRefresh = 0;
  prgBar.Minimum = 0;
  prgBar.Maximum = Convert.ToInt32(dbFile.RecordCount) / refreshInterval;

  bool EOF = false;
  while(!EOF)
  {
      try
      {
         /* Though it seems like we have to read each record one at a time,
          * in reality DG stores the first 10 records the first time we read
          * and then afterwards we simply read from the cache. When those run out, 
          * DG will automatically grab another ten records from the database.
          * Note that 10 is our refresh interval, meaning that this I/O operation
          * occurs at the same time that we update our progress bar. If the blocking
          * factor was higher than our refresh interval, not only would we have to 
          * wait longer to read the first record but the progress bar would go longer
          * without being updated. */
         dbFile.ReadSequential(myDS, ReadSequentialMode.Next, LockRequest.NoWait);
         /* Perform some action on each record here... */
         recordsReadSinceLastRefresh ++;
         if (recordsReadSinceLastRefresh == refreshInterval)
         {
             recordsReadSinceLastRefresh = 0;
             prgBar.PerformStep();
             this.Refresh(); //Refreshes the form.
         }
      }
      catch(dgException dgEx)
      {
          if (dgEx.Error == dgErrorNumber.dgEaEOF)
              EOF = true;
          else
          {
              //Exit procedure or end application here.
          }
      }
  }
  dbFile.Close();
  db.Close()

  /* Using the FileLocks property of a FileAdapter's OpenAttributes,
   * you can set file locking to manual, which allows you to lock more
   * than one record at a time. Note that manual file locking
   * is database dependent- for instance, it will work with a Acceler8
   * database but not with an IBM i. */
  AdgConnection db = createAdgConnection("MyDatabaseName");
  FileAdapter dbFile = new FileAdapter(db, "*Libl/CMASTNEWL1", "CMMASTERL1");
  dbFile.OpenAttributes.FileLocks = FileLocks.Manual;
  dbFile.AccessMode = AccessMode.RWCD;

  AdgDataSet myDS = null;
  dbFile.OpenNewAdgDataSet(out myDS);
  AdgKeyTable keyTbl = myDS.NewKeyTable("RCMMASTL1");

  /* In the code below, we read records for customer numbers
   * 400 - 800. When it ends, we will still have locks on customer numbers
   * 500 and 700. */
  try
  {
      /* Read customer number 400 but don't lock it. */
      keyTbl.Row["CMCUSTNO"] = 400;
      dbFile.ReadRandomKey(myDS, ReadRandomMode.Equal, LockRequest.NoLock, keyTbl);

      /* Read customer number 500 and lock it. */
      keyTbl.Row["CMCUSTNO"] = 500;
      dbFile.ReadRandomKey(myDS, ReadRandomMode.Equal, LockRequest.Read, keyTbl);

      /* Read customer number 600 and lock it. */
      dbFile.ReadSequential(myDS, ReadSequentialMode.Next, LockRequest.Read);

      /* Read customer number 700 and lock it. */
      dbFile.ReadSequential(myDS, ReadSequentialMode.Next, LockRequest.Read);

      /* Read customer number 800 without locking it. */
      dbFile.ReadSequential(myDS, ReadSequentialMode.Next, LockRequest.NoLock);

      /* Unlock customer number 600. */
      keyTbl.Row["CMCUSTNO"] = 600;
      dbFile.ReadRandomKey(myDS, ReadRandomMode.Equal, LockRequest.NoLock, keyTbl);
      dbFile.ReleaseCurrent();

  }
  catch(dgException dgEx)
  {
      MessageBox.Show("Couldn't find one or more records. " + dgEx.Message,
      dgEx.Error.ToString());
  }

  dbFile.Close(); /* Release all locks. */
  db.Close();

  if (dbFile == null)
      dbFile = new FileAdapter();
  if (dbFile.Status == FileAdapter.AdapterStatus.Closed)
  {
      dbFile.SetConnection( myAdgConnection );
      dbFile.FileName = fileName;
      dbFile.MemberName = memberName;
      dbFile.OpenNewAdgDataSet(out myDataSet);
  }
  

  /* Read only records from format one. */
  AdgConnection db = createAdgConnection("MyDatabaseName");
  FileAdapter dbFile = new FileAdapter(db, "*Libl/SalesMem", "SalesMem");
  dbFile.AccessMode = AccessMode.Read | AccessMode.Write;
  AdgDataSet myDS = null;
  dbFile.OpenNewAdgDataSet(out myDS);

  /* Add a record to format 0, "RCustMast". */
  /* Get new customer number to avoid adding a duplicate key. */
  dbFile.ReadSequential(myDS, ReadSequentialMode.Last, LockRequest.Read);
  decimal newCustNo = Convert.ToDecimal(myDS.ActiveRow["CMCustNo"]) + 100m;

  DataRow newRecord = myDS.PrepareRow("RCustMast");
  /* Create a customer record. */

  newRecord["CMCustNo"] = newCustNo;
  newRecord["CMName"] = "Amalgamated Software of North America";
  newRecord["CMAddr1"] = "9901 IH-10 West, Suite 1000";
  newRecord["CMCity"] = "San Antonio";
  newRecord["CMState"] = "TX";
  newRecord["CMCntry"] = "US";
  newRecord["CMPostCode"] = "78230";
  newRecord["CMActive"] = "1";
  newRecord["CMPhone"] = "2104080212";

  myDS.AddPreparedRowAndSetActive(0);
  dbFile.SetFormat("RCustMast");
  try
  {
      dbFile.AddRecord(myDS);
  }
  catch(dgException dgEx)
  {
      if (dgEx.Error != dgErrorNumber.dgEaDUPKEY)
          throw dgEx; /* If the 
            exception wasn't thrown due to a duplicate key, throw it again. */
      MessageBox.Show("Key value \"" + 
            newRecord["CMName"].ToString() +
          "\" already in this 
            file.", "Error");
      dbFile.Close();
      db.Close();
      //Exit procedure or take other action here to 
            avoid adding next record.
  }
  /* Now add a record to format 1, "RSalesMast". */
  DataRow newRecord2 = myDS.PrepareRow("RSalesMast");

  /* Create a record of sales for 2004. */
  newRecord2["CSCustNo"] = newRecord["CMCustNo"];
  newRecord2["CSYear"] = 2004m;
  newRecord2["CSType"] = 1m;
  newRecord2["CSSales01"] = 100m;
  newRecord2["CSSales02"] = 200m;
  newRecord2["CSSales03"] = 300m;
  newRecord2["CSSales04"] = 400m;
  newRecord2["CSSales05"] = 500m;
  newRecord2["CSSales06"] = 600m;
  newRecord2["CSSales07"] = 500m;
  newRecord2["CSSales08"] = 400m;
  newRecord2["CSSales09"] = 200m;
  newRecord2["CSSales10"] = 100m;
  newRecord2["CSSales11"] = 1m;
  newRecord2["CSSales12"] = 0m;

  myDS.AddPreparedRowAndSetActive(1);
  dbFile.SetFormat("RSalesMast");
  try
  {
      dbFile.AddRecord(myDS);
  }
  catch(dgException dgEx)
  {
      if (dgEx.Error != dgErrorNumber.dgEaDUPKEY)
          throw dgEx; /* If the 
            exception wasn't thrown due to a duplicate key, throw it again. */
      MessageBox.Show("Key " + 
            newRecord["CSName"].ToString() + " already in this file.", "Error");
  }

  dbFile.Close();
  db.Close();

  AdgConnection db = createAdgConnection("MyDatabaseName");
  FileAdapter dbFile = new FileAdapter(db, "*Libl/CSMASTERL1", "CSMASTERL1");
  dbFile.AccessMode = AccessMode.Read;
  AdgDataSet myDS = null;
  dbFile.OpenNewAdgDataSet(out myDS);

  /* The code below will find all of the sales for all 
   * customers with a number from 300 to 1400, 
   * and read all the customer numbers from lowest to highest. */
  AdgKeyTable key1 = myDS.NewKeyTable("RCSMASTL1");
  key1.Row["CSCUSTNO"] = Convert.ToDecimal(300);
  key1.KeyPartCount = 1;
  AdgKeyTable key2 = myDS.NewKeyTable("RCSMASTL1");
  key2.Row["CSCUSTNO"] = Convert.ToDecimal(1400);
  key2.KeyPartCount = 1;
  dbFile.SeekRange(RangeMode.First, key1, RangeFirst.Include, key2, RangeLast.Include);

  /* Read until we go past record 1421. */
  bool EOF = false;
  decimal Total = 0;
  while(!EOF)
  {
      try
      {
          dbFile.ReadSequential(myDS, ReadSequentialMode.Next, LockRequest.NoWait);
          for (int j=1; j <= 12; j++)
          {
              string number = j.ToString();
              if (number.Length < 2)
                  number = "0" + number;
              Total += Convert.ToDecimal(myDS.ActiveRow["CSSALES" + number]); 
          }
      }
      catch(dgException dgEx)
      {
          if (dgEx.Error == dgErrorNumber.dgEaEOF)
              EOF = true;
          else
          {
              throw dgEx; //Throw exception if we didn't expect it.
          }
      }
  }
  MessageBox.Show("Total sales for customers 300 to 1400 totalled " 
      + Total.ToString() + ".", "Result");

  dbFile.Close();
  db.Clone();

  AdgConnection db = createAdgConnection("MyDatabaseName");
  FileAdapter dbFile = new FileAdapter(db, "*Libl/CMASTNEWL1", "CMMASTERL1");
  dbFile.AccessMode = AccessMode.Read;
  AdgDataSet myDS = null;
  dbFile.OpenNewAdgDataSet(out myDS);

  /* Seek the file pointer to just before Customer number 1500. */
  AdgKeyTable key = myDS.NewKeyTable("RCMMASTL1");
  key.Row["CMCustNo"] = Convert.ToDecimal(1500);
  dbFile.SeekKey(SeekMode.SetLL, key);
  /* We read the next record to get customer number 1500.*/
  dbFile.ReadSequential(myDS, ReadSequentialMode.Next, LockRequest.Default);
  string CustomerName1 = myDS.ActiveRow["CMName"].ToString();

  /* We set the file pointer to just after customer number 2000. */
  key.Row["CMCustNo"] = Convert.ToDecimal(2000);
  dbFile.SeekKey(SeekMode.SetGT, key);
  /* We read backwards one record to get customer number 2000. */
  dbFile.ReadSequential(myDS, ReadSequentialMode.Previous, LockRequest.Default);
  string CustomerName2 = myDS.ActiveRow["CMName"].ToString();

  /* We set the file pointer to greater than or equal to 2979. */
  key.Row["CMCustNo"] = Convert.ToDecimal(2979);
  dbFile.SeekKey(SeekMode.SetGE, key);
  /* Record 2979 usually does not exist, so we should be on record
  * 3000, which we read by reading the current record (using
  * SeekMode.SetLL would have gotten us record 2900). */
  dbFile.ReadSequential(myDS, ReadSequentialMode.Next, LockRequest.Default);
  string CustomerName3 = myDS.ActiveRow["CMName"].ToString();

  /* We set the file pointer to greater than or equal to 4000. */
  key.Row["CMCustNo"] = Convert.ToDecimal(4000);
  dbFile.SeekKey(SeekMode.SetGE, key);
  /* Record 4000 does exist, and by reading the next record we should access it. */
  dbFile.ReadSequential(myDS, ReadSequentialMode.Next, LockRequest.Default);
  string CustomerName4 = myDS.ActiveRow["CMName"].ToString();

  dbFile.Close();
  db.Close();

AdgConnection db = createAdgConnection("MyDatabaseName");
FileAdapter dbFile = new FileAdapter(db, "Examples/SalesMem", "SalesMem");
dbFile.AccessMode = AccessMode.Read;
AdgDataSet myDS = null;
dbFile.OpenNewAdgDataSet(out myDS);

/* Here we find the name of the customer whose sales (not counting returns) were
 * the best on average in January from 1998 to 2004. This example assumes
 * there are no customer numbers in the second format which are not found in the
 * first format, and that there are no years on record past 1998 to 2004.
 * We use the ResetFormat method to read from both formats, and
 * this gives us the ability to easy see the next customer's name before we
 * read their records. */

decimal total = 0;
decimal currentAverage = 0;
string currentName = "";
decimal maxAverage = -1;
string maxName = "";

dbFile.ResetFormat(); /* Read from both formats automatically. */
/* Make sure we start off on format 0. */
do{
    dbFile.ReadSequential(myDS,ReadSequentialMode.Next, LockRequest.Read);
  }while(dbFile.CurrentFormatIndex != 0);
try /* Read until end of file. Throw exception again if it was not due to EOF. */
    {
    while(true) /* Hitting end of file will throw an exception and let us leave. */
    {
/* Remember, the ActiveRow changes depending on the current format. */
        currentName = myDS.ActiveRow["CMName"].ToString();
        total = 0;
        dbFile.ReadSequential(myDS, ReadSequentialMode.Next, LockRequest.Read);
        while (dbFile.CurrentFormatIndex == 1)
        {
            total += Convert.ToDecimal(myDS.ActiveRow["CSSales01"]);
            dbFile.ReadSequential(myDS, ReadSequentialMode.Next, LockRequest.Read);
        }
/* there could be as many as seven records from 1998 - 2004. */
        currentAverage = total / 7;
        if (currentAverage > maxAverage)
        {
            maxName = currentName;
            maxAverage = currentAverage;
        }
    }
}
catch(dgException dgEx)
{
    if (dgEx.Error != dgErrorNumber.dgEaEOF)
        throw dgEx;
}
string decimalResult = maxAverage.ToString();
decimalResult = decimalResult.Substring(0, decimalResult.IndexOf('.') + 3);
MessageBox.Show("The cusomter with the highest average sales in " +
    "January from 1998 - 2004 is \"" + maxName +
     "\", with an average of " + decimalResult + ".",
     "Result");
dbFile.Close();
db.Close();

 /* Here, we are using a pre-initialized FileAdapter (named "dbFile")
  * which was opened using AccessMode.RWCD, which automatically locks
  * each read record read, so it will remain unchanged until we
  * update it or read a new record. Here we don't want to
  * update the record if the customer is not from Texas, and if
  * this code is being called by unknown client code it could be awhile
  * before the next read. In order to remove the lock without
  * performing some additional action, we use the ReleaseCurrent method . */
 dbFile.ReadSequential(myDS, ReadSequentialMode.Next, LockRequest.Default);
 if (myDS.ActiveRow["CMState"].ToString() == "TX" &&
     myDS.ActiveRow["CMActive"].ToString() == "0")
 {
     myDS.ActiveRow["CMActive"] = '1';
     dbFile.ChangeCurrent(myDS);
 }
 else
 {
     dbFile.ReleaseCurrent();
 }

  AdgConnection db = createAdgConnection("MyDatabaseName");
  FileAdapter dbFile = new FileAdapter(db, "*Libl/CMASTNEWL1", "CMMASTERL1");
  dbFile.AccessMode = AccessMode.Read;
  AdgDataSet myDS = null;

  int refreshInterval = 10; //Used so we don't slow down refreshing too much...
  dbFile.OpenAttributes.BlockingFactor = refreshInterval;
  dbFile.OpenNewAdgDataSet(out myDS);

  /* Here, we read every record until end of file is reached.
   * Because this is an fairly long process, we set up a progress bar
   * to keep the user from being discouraged. We set its Maximum
   * value to the number of records in the file, which is found
   * using FileAdapter's RecordCount propert, divided by
   * our refreshInterval. */
  int recordsReadSinceLastRefresh = 0;
  prgBar.Minimum = 0;
  prgBar.Maximum = Convert.ToInt32(dbFile.RecordCount) / refreshInterval;

  bool EOF = false;
  while(!EOF)
  {
      try
      {
          /* Though it seems like we have to read each record one at a time,
           * in reality DG stores the first 10 records the first time we read
           * and then afterwards we simply read from the cache. When those run out, 
           * DG will automatically grab another ten records from the database.
           * Note that 10 is our refresh interval, meaning that this I/O operation
           * occurs at the same time that we update our progress bar. If the blocking
           * factor was higher than our refresh interval, not only would we have to 
           * wait longer to read the first record but the progress bar would go longer
           * without being updated. */
          dbFile.ReadSequential(myDS, ReadSequentialMode.Next, LockRequest.NoWait);
          /* Perform some action on each record here... */
          recordsReadSinceLastRefresh ++;
          if (recordsReadSinceLastRefresh == refreshInterval)
          {
              recordsReadSinceLastRefresh = 0;
              prgBar.PerformStep();
              this.Refresh(); //Refreshes the form.
          }
      }
      catch(dgException dgEx)
      {
          if (dgEx.Error == dgErrorNumber.dgEaEOF)
              EOF = true;
          else
          {
              //Exit procedure or end application here.
          }
      }
  }
  dbFile.Close();
  db.Close();

   AdgConnection db = createAdgConnection("MyDatabaseName");
   FileAdapter dbFile = new FileAdapter(db, "*Libl/CMASTNEWL1",
           "CMMASTERL1");
   dbFile.AccessMode = AccessMode.Read;
   AdgDataSet myDS = null;
   dbFile.OpenNewAdgDataSet(out myDS);

   /* Read the first record (in terms of Customer number, which CMASTNEWL1 is
    * keyed by.) */
   dbFile.ReadSequential(myDS, ReadSequentialMode.First, LockRequest.Default);
   string FirstCustomerName = myDS.ActiveRow["CMCustNo"].ToString();

   /* Seek the file pointer to just before Customer number 1500. */
   AdgKeyTable key = myDS.NewKeyTable("RCMMastL1");
   key.Row["CMCustNo"] = Convert.ToDecimal(1500);
   dbFile.SeekKey(SeekMode.SetLL, key);
   /* We read the next record to get customer number 1500.*/
   dbFile.ReadSequential(myDS, ReadSequentialMode.Next, LockRequest.Default);
   string OneThousandFiveHundrethCustomerName =
           myDS.ActiveRow["CMName"].ToString();

  AdgConnection db = createAdgConnection("MyDatabaseName");
  FileAdapter dbFile = new FileAdapter(db, "*Libl/CSMASTERL1", "CSMASTERL1");
  dbFile.AccessMode = AccessMode.Read;
  AdgDataSet myDS = null;
  dbFile.OpenNewAdgDataSet(out myDS);

  /* We read all of the records for customer 300 in order to get 
   * their net sales as well as their average yearly gross sales
   * and returns. */
  AdgKeyTable custNoKey = myDS.NewKeyTable("RCSMastL1");
  custNoKey.Row["CSCustNo"] = Convert.ToDecimal(300);
  custNoKey.KeyPartCount = 1; //Only use the first field of the key.
  decimal totalSales = 0;
  decimal totalReturns = 0;
  int saleRecordsRead = 0;
  int returnRecordsRead = 0;
  bool EOF = false;
  /* Because ReadSequentialEqual will return EOF if the record
   * it immediately gets is not equal to its search key, we need
   * to first seek to an equal record. */ 
  dbFile.SeekKey(SeekMode.SetLL, custNoKey);
  while(!EOF){
      try{
          dbFile.ReadSequentialEqual(myDS, ReadEqualMode.NextEqual, LockRequest.Read, custNoKey);
          if (Convert.ToDecimal(myDS.ActiveRow["CSType"]) == 1)
          {
              totalSales += Convert.ToDecimal(myDS.ActiveRow["CSSales01"]) + 
                  Convert.ToDecimal(myDS.ActiveRow["CSSales02"]) +
                  Convert.ToDecimal(myDS.ActiveRow["CSSales03"]) + 
                  Convert.ToDecimal(myDS.ActiveRow["CSSales04"]) +
                  Convert.ToDecimal(myDS.ActiveRow["CSSales05"]) + 
                  Convert.ToDecimal(myDS.ActiveRow["CSSales06"]) +
                  Convert.ToDecimal(myDS.ActiveRow["CSSales07"]) + 
                  Convert.ToDecimal(myDS.ActiveRow["CSSales08"]) +
                  Convert.ToDecimal(myDS.ActiveRow["CSSales09"]) + 
                  Convert.ToDecimal(myDS.ActiveRow["CSSales10"]) +
                  Convert.ToDecimal(myDS.ActiveRow["CSSales11"]) + 
                  Convert.ToDecimal(myDS.ActiveRow["CSSales12"]);
              saleRecordsRead ++;
          }
          else
          {
              totalReturns -= Convert.ToDecimal(myDS.ActiveRow["CSSales01"]) + 
                  Convert.ToDecimal(myDS.ActiveRow["CSSales02"]) +
                  Convert.ToDecimal(myDS.ActiveRow["CSSales03"]) + 
                  Convert.ToDecimal(myDS.ActiveRow["CSSales04"]) +
                  Convert.ToDecimal(myDS.ActiveRow["CSSales05"]) + 
                  Convert.ToDecimal(myDS.ActiveRow["CSSales06"]) +
                  Convert.ToDecimal(myDS.ActiveRow["CSSales07"]) + 
                  Convert.ToDecimal(myDS.ActiveRow["CSSales08"]) +
                  Convert.ToDecimal(myDS.ActiveRow["CSSales09"]) + 
                  Convert.ToDecimal(myDS.ActiveRow["CSSales10"]) +
                  Convert.ToDecimal(myDS.ActiveRow["CSSales11"]) + 
                  Convert.ToDecimal(myDS.ActiveRow["CSSales12"]);
              returnRecordsRead ++;
          }
      }
      catch(dgException dgEx){
          if (dgEx.Error == dgErrorNumber.dgEaEOF)
          {
              EOF = true;
          }
          else
          {
              MessageBox.Show("Error getting next record for customer 300:" + 
                  dgEx.Message, "Error");
              //Exit procedure or end application here.
          }
      }
  }
  /* Compute additional results. */
  decimal netSales = totalSales - totalReturns;
  decimal averageSalesPerYear;
  if (saleRecordsRead > 0)
      averageSalesPerYear = totalSales / saleRecordsRead;
  else
      averageSalesPerYear = 0;
  decimal averageReturnsPerYear;
  if (returnRecordsRead > 0)
      averageReturnsPerYear = totalReturns / returnRecordsRead;
  else
      averageReturnsPerYear = 0;
  dbFile.Close();
  db.Close();

  AdgConnection db = createAdgConnection("MyDatabaseName");
  FileAdapter dbFile = new FileAdapter(db, "*Libl/CMASTNEWL1", 
            "CMMASTERL1");
  dbFile.AccessMode = AccessMode.Read;

  AdgDataSet myDS = null;
  try
  {
      dbFile.OpenNewAdgDataSet(out myDS);
  }
  catch(dgException dgEx)
  {
      MessageBox.Show("Error opening file! " + 
            dgEx.Message, "Error");
      //Exit procedure or end application here.
  }

  /* We read all records with a customer number greater
   * than, but not equal to 10000 and less than or equal
   * to, 40000. */
  AdgKeyTable OneKey = myDS.NewKeyTable("RCMMastL1");
  OneKey.Row["CMCustNo"] = 10000;
  AdgKeyTable TwoKey = myDS.NewKeyTable("RCMMastL1");
  TwoKey.Row["CMCustNo"] = 40000;

  try
  {
      dbFile.ReadRange(myDS, RangeMode.First,
      LockRequest.Read, OneKey,
      RangeFirst.Exclude, TwoKey,
      RangeLast.Include);
  }
  catch(dgException dgEx)
  {
      MessageBox.Show("Error getting records 
            10000-40000 :" +
          dgEx.Message, "Error");
      //Exit procedure or end application here.
  }

  int totalSum = 0;
  int activeSum = 0;
  bool EOF = false;
  while(!EOF)
  {
      try
      {

            dbFile.ReadSequential(myDS, ReadSequentialMode.Next, 
            LockRequest.NoWait);
          if (Convert.ToChar(myDS.ActiveRow["CMActive"]).ToString() 
            == "1")
          activeSum ++;
          totalSum ++;
      }
      catch(dgException dgEx)
      {
          if (dgEx.Error == 
            dgErrorNumber.dgEaEOF)

            EOF = true;
          else
          {
 
            //Exit procedure or end application here.
          }
      }
  }

  string percent = Convert.ToDecimal((Convert.ToDecimal(activeSum)
      /Convert.ToDecimal(totalSum)) * 100).ToString();
  MessageBox.Show(percent.Substring(0, percent.IndexOf('.')) +
      "% of the customers sampled are active.");
  dbFile.Close();
  db.Close(); 

  AdgConnection db = createAdgConnection("MyDatabaseName");
  FileAdapter dbFile = new FileAdapter(db, "*Libl/CMASTNEWL1", "CMMASTERL1");
  dbFile.AccessMode = AccessMode.Read;
  AdgDataSet myDS = null;
  dbFile.OpenNewAdgDataSet(out myDS);
  /* We retrieve the record for customer number 92300. */
  AdgKeyTable keyTbl = myDS.NewKeyTable("RCMMASTL2");
  keyTbl.Row["CMCUSTNO"] = 92300;
  try
  {
      dbFile.ReadRandomKey(myDS, ReadRandomMode.Equal, LockRequest.Default, keyTbl);
  }
  catch(dgException dgEx)
  {
      MessageBox.Show("Error finding the record: " + dgEx.Message,
          dgEx.Error.ToString());
  }

  dbFile.Close();
  db.Close();

  AdgConnection db = createAdgConnection("MyDatabaseName");
  FileAdapter dbFile = new FileAdapter(db, "*Libl/CMASTNEWL1", "CMMASTERL1");
  dbFile.AccessMode = AccessMode.Read; 
  AdgDataSet myDS = null;

  string[] keys = new string[]{"CMCUSTNO"};
  KeyUsages[] usages = new KeyUsages[]{KeyUsages.ASCEND};

  /* Read the first customer name listed for Texas. */
  dbFile.OpenSimpleQuery(ref myDS, "*UNIQUE", "CMSTATE=\"TX\"", keys, usages);
  dbFile.ReadSequential(myDS, ReadSequentialMode.First, LockRequest.Read);
  string FirstInTexas = myDS.ActiveRow["CMName"].ToString();
  /* First close the file to avoid throwing an exception... */
  dbFile.Close();
  /* Read the first customer name listed in Tennessee. */ 
  dbFile.OpenSimpleQuery(ref myDS, "*UNIQUE", "CMSTATE=\"TN\"", keys, usages);
  dbFile.ReadSequential(myDS, ReadSequentialMode.First, LockRequest.Read);
  string FirstInTennessee = myDS.ActiveRow["CMName"].ToString();

  dbFile.Close();
  db.Close();

  AdgConnection db = createAdgConnection("MyDatabaseName");
  FileAdapter dbFile = new FileAdapter(db, "*Libl/CMASTNEWL1", "CMMASTERL1");
  dbFile.AccessMode = AccessMode.Read;

  /* The AdgDataSet consists of data read from the database file
   * using the FileAdapter class. It also must be used in most
   * of the FileAdapter's operations. */
  AdgDataSet myDS = null;
  try
  {
      dbFile.OpenNewAdgDataSet(out myDS);
  }
  catch(dgException dgEx)
  {
      /* There are many reasons why opening a file can fail. Here, we
       * catch some of the more general ones. */
      if (dgEx.Error == dgErrorNumber.dgEmMNOTFND)
          MessageBox.Show("Member " + dbFile.MemberName + " not found!", "Error opening file");
      else if (dgEx.Error == dgErrorNumber.dgEmFNOTFND)
          MessageBox.Show("File " + dbFile.FileName + " not found!", "Error opening file");
      else
          MessageBox.Show(dgEx.Message, "Error opening file");
      //Exit procedure here.
  }

  /* The code below finds the names of every data field in the 
   * file "*Libl/CMASTNEWL1" and puts them into an array list. */
  ArrayList fieldNames = new ArrayList();

  for (int i = 0; i < myDS.Formats; i ++)
  {
      foreach(DataColumn column in myDS.Tables[i].Columns)
      {
          fieldNames.Add(column.ToString());
      }
  } 

  dbFile.Close();
  db.Close();

  /* Unlike OpenNewAdgDataSet, the Open method does not create
   * a new AdgDataSet to meet the requirements of the file being
   * opened. However, it is slightly faster because of this, so
   * Open is a preferable way to open a file if a suitable.
   * AdgDataSet already exists or you don't need one. 
   * Note, however, that opening a file is a relatively slow
   * operation and the need to reopen a file rarely occurs. */

  FileAdapter dbFile = new FileAdapter();
  dbFile.SetConnection( createAdgConnection("MyDatabaseName") );
  dbFile.FileName = "*Libl/CMASTNEW";
  dbFile.MemberName = "CMMASTER";
  AdgDataSet myDS = null;

  /* Only need to open the file to show the number of records,
   * then we're through with it. */
  dbFile.Open(myDS); /* Will not initialize the data set. */

  MessageBox.Show("Number of deleted and non-deleted records still " +
      "taking up space in file \"" + dbFile.FileName +
      "\" is " + dbFile.FileLength.ToString());
  dbFile.Close();
  dbFile.Connection.Close();

  AdgConnection db = createAdgConnection("MyDatabaseName");
  FileAdapter dbFile = new FileAdapter(db, "*Libl/CMASTNEWL1", "CMMASTERL1");
  dbFile.AccessMode = AccessMode.Read;
  AdgDataSet myDS = null;

  int refreshInterval = 10; //Used so we don't slow down refreshing too much...
  dbFile.OpenAttributes.BlockingFactor = refreshInterval;
  dbFile.OpenNewAdgDataSet(out myDS);

  /* Here, we read every record until end of file is reached.
   * Because this is an fairly long process, we set up a progress bar
   * to keep the user from being discouraged. We set its Maximum
   * value to the number of records in the file, which is found
   * using FileAdapter's RecordCount property, divided by
   * our refreshInterval. */
  int recordsReadSinceLastRefresh = 0;
  prgBar.Minimum = 0;
  prgBar.Maximum = Convert.ToInt32(dbFile.RecordCount) / refreshInterval;

  bool EOF = false;
  while(!EOF)
  { 
      try
      {
          /* Though it seems like we have to read each record one at a time,
           * in reality DG stores the first 10 records the first time we read
           * and then afterwards we simply read from the cache. When those run out, 
           * DG will automatically grab another ten records from the database.
           * Note that 10 is our refresh interval, meaning that this I/O operation
           * occurs at the same time that we update our progress bar. If the blocking
           * factor was higher than our refresh interval, not only would we have to 
           * wait longer to read the first record but the progress bar would go longer
           * without being updated. */
          dbFile.ReadSequential(myDS, ReadSequentialMode.Next, LockRequest.NoWait);
          /* Perform some action on each record here... */
          recordsReadSinceLastRefresh ++;
          if (recordsReadSinceLastRefresh == refreshInterval)
          {
              recordsReadSinceLastRefresh = 0;
              prgBar.PerformStep();
              this.Refresh(); //Refreshes the form.
          }
      }
      catch(dgException dgEx)
      {
          if (dgEx.Error == dgErrorNumber.dgEaEOF)
              EOF = true;
          else
          {
              //Exit procedure or end application here.
          }
      }
  }
  dbFile.Close();
  db.Close();

  /* We attempt to open the class variable FileAdapter "dbFile" 
   * which may or may not have been initialized another routine. */
  public void OpenFile(){
      AdgDataSet myDS = null;
      if (dbFile == null)
      {
          MessageBox.Show("FileAdapter not initialized.");
          return;
      }
      try
      {
          dbFile.OpenNewAdgDataSet(out myDS);
      }
      catch(dgException dgEx)
      {
          if (dgEx.Error == dgErrorNumber.dgEmMNOTFND)
          {
              MessageBox.Show("Member " + dbFile.MemberName + " not found!");
          }
          else if (dgEx.Error == dgErrorNumber.dgEmFNOTFND)
          {
              MessageBox.Show("File " + dbFile.FileName + " not found!");
          }
          else 
          {
              MessageBox.Show("Couldn't open file!" + dgEx.Message, "");
          } 
          // Exit routine or end application here.
      }
  }
 

  /* Will open up "CustReport" and will write a single detail, and
   * change its background color. */
  AdgConnection dataBase = createAdgConnection("MyDatabaseName");
  FileAdapter printFile = new FileAdapter(dataBase, "*Libl/CustReport", "*First");
  printFile.AccessMode = AccessMode.PrintPreview;
  AdgDataSet dataSet;
  printFile.OpenNewAdgDataSet(out dataSet);

  DataRow dr = dataSet.PrepareRow("rptDetail");
  dr["prtCMName"] = "This line is light blue.";

  IPrintProperties ip = printFile.GetPrintProperties("rptDetail");
  int oleColor = ColorTranslator.ToOle(Color.LightBlue);
  ip.SetValue("lblRowColor", "BackColor", oleColor);

  dataSet.AddRow("rptDetail");
  printFile.SetFormat("rptDetail");
  printFile.AddRecord(dataSet);

  printFile.Close(); /* Shows print preview - can also accomplish this with
                      * ForceEOD, which doesn't close the file. */
  dataBase.Close();

  /* In this simple routine we wish to write the format names 
   * of a file to a combo box using the FileAdapter "dbFile" 
   * and its accompanying AdgDataSet "myDS", which may or 
   * may not have been initialized and opened elsewhere. */
  if (dbFile == null)
  {
      MessageBox.Show("Error- FileAdapter not initialized.");
      return;
  }
  if (dbFile.Status != FileAdapter.AdapterStatus.Open)
  {
      MessageBox.Show("Error- "+ dbFile.FileName + " not open.");
      return;
  }
  if (myDS == null)
  {
      MessageBox.Show("DataSet not initialized!");
      return;
  }

  for (int i = 0; i < myDS.Formats; i ++)
  {
      /* List the format names in the combo box "cbFmtNames". */
      cbFmtNames.Items.Add(myDS.GetFormatName(i));
  }

  FileAdapter dbFile = new FileAdapter();
  dbFile.SetConnection( createAdgConnection("MyDatabaseName") );
  dbFile.FileName = "*Libl/CMASTNEW";
  dbFile.MemberName = "CMMASTER";
  AdgDataSet myDS = null;
  dbFile.Open(myDS); /* Will not initialize the data set. */

  /* Figure out the number of records which were logically 
   * deleted but are still taking up space on the physical file.
   * FileLength returns the number of deleted and non-deleted 
   * records stored on a physical file, while RecordCount returns
   * the number of non-deleted records only. */
  long deletedRecords = dbFile.FileLength - dbFile.RecordCount;
  MessageBox.Show("Number of deleted records still taking up space in file \"" 
      + dbFile.FileName + "\" is " + deletedRecords.ToString());
  dbFile.Close();
  dbFile.Connection.Close();

  AdgConnection dataBase = createAdgConnection("MyDatabaseName");
  FileAdapter dbFile = new FileAdapter(dataBase);
  dbFile.FileName = "*Libl/CMASTNEWL1";
  dbFile.MemberName = "CMMASTERL1";

  AdgConnection dataBase = createAdgConnection("MyDatabaseName");
  FileAdapter dbFile = new FileAdapter();
  dbFile.SetConnection( dataBase;
  dbFile.FileName = "*Libl/CMASTNEWL1";
  dbFile.MemberName = "CMMASTERL1";

  AdgConnection db = createAdgConnection("MyDatabaseName");
  using (FileAdapter dbFile = new FileAdapter(db, "*Libl/CMASTNEWL1", "CMMASTERL1"))
  {
      dbFile.AccessMode = AccessMode.Read;
      AdgDataSet myDS = null;
      dbFile.OpenNewAdgDataSet(out myDS);

      /* Seek the file pointer to just before Customer number 3000. */
      AdgKeyTable key = myDS.NewKeyTable("RCMMastL1");
      key.Row["CMCustNo"] = Convert.ToDecimal(3000);
      dbFile.SeekKey(SeekMode.SetGE, key);
      /* We check to see if we matched 3000 or if we went beyond it. */
      if (dbFile.ExactSeek)
          MessageBox.Show("Record 3000 exists.");
      else
          MessageBox.Show("Record 3000 not found.");
      /* Now we try to find Customer number 1125. */
      key.Row["CMCustNo"] = Convert.ToDecimal(1125);
      dbFile.SeekKey(SeekMode.SetGE, key);
      if (dbFile.ExactSeek)
          MessageBox.Show("Record 1125 exists.");
      else
          MessageBox.Show("Record 1125 not found.");
  }//Using statement automatically closes dbFile.
  db.Close();

  AdgConnection db = createAdgConnection("MyDatabaseName");
  FileAdapter dbFile = new FileAdapter(db, "*Libl/CMASTNEWL1", "CMMASTERL1");
  dbFile.AccessMode = AccessMode.Delete | AccessMode.Read;

  AdgDataSet myDS = null;
  try
  {
      dbFile.OpenNewAdgDataSet(out myDS);
  }
  catch(dgException dgEx)
  {
      MessageBox.Show("Error opening file! " + dgEx.Message, "Error");
      //Exit procedure or end application here.
  }

  /* We erase all records with a customer number equal to
   * or greater than 5000 and less than, but not
   * equal to, 6000. */
  AdgKeyTable OneKey = myDS.NewKeyTable("RCMMastL1");
  OneKey.Row["CMCustNo"] = 5000;
  AdgKeyTable TwoKey = myDS.NewKeyTable("RCMMastL1");
  TwoKey.Row["CMCustNo"] = 6000;
  try
  {
      dbFile.DeleteRange(OneKey, RangeFirst.Include, TwoKey, RangeLast.Exclude);
  }
  catch(dgException dgEx)
  {
      MessageBox.Show("Error deleting records 5000-6000 :" +
          dgEx.Message, "Error");
  }

  dbFile.Close();
  db.Close();

  AdgConnection db = createAdgConnection("MyDatabaseName");
  FileAdapter dbFile = new FileAdapter(db, "*Libl/CMASTNEWL1", "CMMASTERL1");
  /* Open a file for reading and deleting- this allows us to delete a record by its key value. */
  dbFile.AccessMode = AccessMode.Delete | AccessMode.Read;

  AdgDataSet myDS = null;
  try
  {
      dbFile.OpenNewAdgDataSet(out myDS);
  }
  catch(dgException dgEx)
  {
      MessageBox.Show("Error opening file! " + dgEx.Message, "Error");
      //Exit procedure or end application here.
  }

  /* We retrieve the record for customer number 82900 and delete it! */
  AdgKeyTable keyTbl = myDS.NewKeyTable("RCMMASTL1");
  keyTbl.Row["CMCustNo"] = 82900;
  dbFile.DeleteKey(keyTbl);

  dbFile.Close();
  db.Close();

  AdgConnection db = createAdgConnection("MyDatabaseName");
  FileAdapter dbFile = new FileAdapter(db, "*Libl/CMASTNEWL1", "CMMASTERL1");
  dbFile.AccessMode = AccessMode.Read | AccessMode.Delete;

  AdgDataSet myDS = null;
  try
  {
      dbFile.OpenNewAdgDataSet(out myDS);
  }
  catch(dgException dgEx)
  {
      MessageBox.Show("Error opening file! " + dgEx.Message, "Error");
      //Exit procedure or end application here.
  }

  dbFile.ReadSequential(myDS, ReadSequentialMode.First, LockRequest.Default);

  /* We retrieve the record for customer number 7800... */
  AdgKeyTable keyTbl = myDS.NewKeyTable("RCMMASTL1");
  keyTbl.Row["CMCUSTNO"] = 7800;
  try
  {
      dbFile.ReadRandomKey(myDS, ReadRandomMode.Equal, LockRequest.Default, keyTbl);
      /*... and delete it! */
      dbFile.DeleteCurrent();
  }
  catch(dgException dgEx)
  {
      MessageBox.Show("Error deleting the record: " + dgEx.Message,
      dgEx.Error.ToString());
  }

  dbFile.Close();
  db.Close();

  /* We open the file in order to delete all of its records. */
  AdgConnection db = createAdgConnection("MyDatabaseName");
  FileAdapter dbFile = new FileAdapter(db, "*Libl/CMASTNEW", "CMMASTER");
  dbFile.AccessMode = AccessMode.Delete;
  /* Its generally good practice to make sure you have an exclusive lock
   * on a file that you are deleting all of the records from, but some
   * databases do not require it. */
  dbFile.OpenAttributes.ShareTypes = ShareTypes.Exclusive;
  AdgDataSet myDS = null;

  try
  {
      dbFile.Open(myDS);
  }
  catch(dgException dgEx)
  {
      db.Close();
      if (dgEx.Error == dgErrorNumber.dgEmBUSYOBJ)
      {
          MessageBox.Show("Couldn't open the file for exclusive access.", "Error opening file.");
          //Exit routine or procedure here to avoid preceding file operations.
      }
      else 
          throw dgEx;
  }
  dbFile.DeleteAllRecords();
  
  dbFile.Close();
  db.Close();

  /* Initialize a new fileadapter. Since the AdgConnection is needed
   * only for this file adapter, it is created and destroyed using the
   * FileAdapter's Connection property. */
  FileAdapter dbFile = new FileAdapter();
  dbFile.SetConnection( createAdgConnection("MyDatabaseName") );
  dbFile.FileName = "*Libl/CMASTNEWL2";
  dbFile.MemberName = "CMMASTERL2";
  dbFile.AccessMode = AccessMode.Read;

  AdgDataSet myDS = null;
  dbFile.OpenNewAdgDataSet(out myDS);

  /* Find first record beginning with M. */
  AdgKeyTable keyTbl = myDS.NewKeyTable("RCMMASTL2");
  keyTbl.Row["CMName"] = "M";
  dbFile.SeekKey(SeekMode.SetLL, keyTbl);

  dbFile.ReadSequential(myDS, ReadSequentialMode.Next, LockRequest.Read);
  string firstMCustomer = myDS.ActiveRow["CMName"].ToString();

  dbFile.Close(); /* Close file. */
  dbFile.Connection.Close(); /* Close database. */

  AdgConnection db = createAdgConnection("MyDatabaseName");
  FileAdapter dbFile = new FileAdapter(db, "*Libl/CMASTNEWL1", "CMMASTERL1");
  dbFile.AccessMode = AccessMode.Read;
  AdgDataSet myDS = null;

  /* Though all open files will automatically be closed when a process
   * is terminated, it is good practice to close them as soon as you are
   * finished with them. You also may need to close a file in order
   * to reopen it with different attributes or to open it as a query file. */

  /* Read the first customer name listed for Texas. */
  string[] keys = new string[]{"CMCUSTNO"}; //The key fields used in our query.
  KeyUsages[] usages = new KeyUsages[]{KeyUsages.ASCEND}; //How we use them.

  dbFile.OpenSimpleQuery(ref myDS, "*UNIQUE", "CMSTATE=\"TX\"", keys, usages);
  dbFile.ReadSequential(myDS, ReadSequentialMode.First, LockRequest.Read);
  string FirstInTexas = myDS.ActiveRow["CMName"].ToString();

  /* Going to try a new query- first we close the file to avoid 
   * throwing an exception... */
  dbFile.Close();
  /* Read the first customer name listed in Tennessee. */ 
  dbFile.OpenSimpleQuery(ref myDS, "*UNIQUE", "CMSTATE=\"TN\"", keys, usages);
  dbFile.ReadSequential(myDS, ReadSequentialMode.First, LockRequest.Read);
  string FirstInTennessee = myDS.ActiveRow["CMName"].ToString();

  dbFile.Close();
  db.Close();

  AdgConnection db = createAdgConnection("MyDatabaseName");
  FileAdapter dbFile = new FileAdapter(db, "*Libl/CMASTNEWL1", "CMMASTERL1");
  dbFile.AccessMode = AccessMode.Read | AccessMode.Change;

  AdgDataSet myDS = null;
  try
  {
      dbFile.OpenNewAdgDataSet(out myDS);
  }
  catch(dgException dgEx)
  {
      MessageBox.Show("Error opening file! " + dgEx.Message, "Error");
      //Exit procedure or end application here.
  }
  /* We read the first record of the file... */
  dbFile.ReadSequential(myDS, ReadSequentialMode.First, LockRequest.Default);
  myDS.SetActive(myDS.GetFormatName(0), 0); 
  /* ...and make the customer name all caps. */
  string CustName = System.Convert.ToString(myDS.ActiveRow["CMName"]);
  CustName = CustName.ToUpper();
  myDS.ActiveRow["CMName"] = CustName;
  try
  {
      /* Here we update the record. */
      dbFile.ChangeCurrent(myDS);
  }
  catch (dgException dgEx)
  {
      MessageBox.Show("Error updating record: " + dgEx.Message, "Error.");
      // Exit routine or take alternative action here.
      test.Actual = "Catch occured.";
  }

  dbFile.Close();
  db.Close();

  AdgConnection db = createAdgConnection("MyDatabaseName");
  FileAdapter dbFile = new FileAdapter(db, "*Libl/CMASTNEWL1", 
            "CMMASTERL1");
  dbFile.AccessMode = AccessMode.RWCD;

  AdgDataSet myDS = null;
  try
  {
     db.Open();
     dbFile.OpenNewAdgDataSet(out myDS);
  }
  catch(dgException dgEx)
  {
     MessageBox.Show("Error opening file! " + dgEx.Message, 
            "Error");
     //Exit procedure or end application here.
  }

  DataRow newRow = myDS.PrepareRow(0);
  newRow["CMCustNo"] = 50;
  newRow["CMName"] = "Amalgamated Software of North America";
  newRow["CMAddr1"] = "IH-10 West";
  newRow["CMCity"] = "San Antonio";
  newRow["CMState"] = "TX";
  newRow["CMCntry"] = "US";
  newRow["CMPostCode"] = "78230";
  newRow["CMActive"] = "1";
  newRow["CMFax"] = "2105554679";
  newRow["CMPhone"] = "555-4678";
  myDS.AddPreparedRowAndSetActive(0);
  try
  {
     dbFile.AddRecord(myDS);
  }
  catch (dgException dgEx)
  {
     MessageBox.Show("Adding new record was unsuccessful! "
        + dgEx.Message, "Error!");
     //Exit procedure or end application here.
  }

  FileAdapter dbFile = new FileAdapter();
  dbFile.SetConnection( createAdgConnection("MyDatabaseName") );
  dbFile.FileName = "*Libl/CMASTNEWL1";
  dbFile.MemberName = "CMMASTERL1";

  /* Open a file for reading and deleting- this allows us to delete a record by its key value. */
  dbFile.AccessMode = AccessMode.Read | AccessMode.Delete;
  AdgDataSet myDS = null;
  dbFile.OpenNewAdgDataSet(out myDS);

  /* We retrieve the record for customer number 82900 and delete it! */
  AdgKeyTable keyTbl = myDS.NewKeyTable("RCMMASTL1");
  keyTbl.Row["CMCustNo"] = 82900m;
  try
  {
      dbFile.DeleteKey(keyTbl);
  }
  catch(dgException dgEx)
  {
      if (dgEx.Error == dgErrorNumber.dgEaNOTFND)
      {
          MessageBox.Show("Record not found. ");
      }
  }
  dbFile.Close();
  dbFile.Connection.Close();