OpenSchema Method Example (VJ++)
This example uses the OpenSchema method to display the name and type of each table in the Pubs database.
// BeginOpenSchemaJ import com.ms.wfc.data.*; import java.io.*; import com.ms.com.*; public class OpenSchemaX { // The main entry point of the application. public static void main (String[] args) { System.out.println("\nResults for OpenSchemaX:\n\n"); OpenSchemaX(); System.out.println("\nResults for OpenSchemaX2:\n\n"); OpenSchemaX2(); System.exit(0); } // OpenSchemaX Function static void OpenSchemaX() { // Define ADO Objects Connection cnn1 = null; Recordset rstSchema = null; // Declarations String strCnn; BufferedReader in = new BufferedReader(new InputStreamReader(System.in)); int intDisplayRecords = 5; int intRecordCount = 0; try { cnn1 = new Connection(); strCnn = "Provider = Microsoft.Jet.OLEDB.4.0;" + "Data Source=C:\\Program Files\\Microsoft " + "Office\\Office\\Samples\\Northwind.mdb;"; cnn1.open(strCnn); rstSchema = cnn1.openSchema(AdoEnums.Schema.TABLES); while (!rstSchema.getEOF()) { System.out.println("Table Name: " + rstSchema.getField("TABLE_NAME").getString()+"\n"+ "Table Type: " + rstSchema.getField("TABLE_TYPE").getString()+"\n"); intRecordCount++; if ( intRecordCount == intDisplayRecords) { System.out.println("Press <Enter> to continue.."); in.readLine(); intRecordCount = 0; } rstSchema.moveNext(); } System.out.println("Press <Enter> to continue.."); in.readLine(); } catch(AdoException ae) { // Notify user of any errors that result from ADO. // As passing a Recordset, check for null pointer first. if(rstSchema != null) { PrintProviderError(rstSchema.getActiveConnection()); } else { System.out.println("Exception: " + ae.getMessage()); } } // System read requires this catch. catch(java.io.IOException je) { PrintIOError(je); } finally { // Cleanup objects before exit. if (rstSchema != null) if (rstSchema.getState() == 1) rstSchema.close(); if (cnn1 != null) if (cnn1.getState() == 1) cnn1.close(); } } // OpenSchemaX2 Function static void OpenSchemaX2() { // Define ADO Objects Connection cnn2 = null; Recordset rstSchema = null; // Declarations String strCnn; BufferedReader in = new BufferedReader(new InputStreamReader(System.in)); int intDisplayRecords = 5; int intRecordCount = 0; try { cnn2 = new Connection(); strCnn = "Provider = Microsoft.Jet.OLEDB.4.0;" + "Data Source=C:\\Program Files\\Microsoft " + "Office\\Office\\Samples\\Northwind.mdb;"; cnn2.open(strCnn); Variant[] va = new Variant[4]; va[0] = new Variant(); va[1] = new Variant(); va[2] = new Variant(); va[3] = new Variant("VIEW"); rstSchema = cnn2.openSchema(AdoEnums.Schema.TABLES,(Object[])va); while (!rstSchema.getEOF()) { System.out.println("Table Name: " + rstSchema.getField("TABLE_NAME").getString()+"\n"+ "Table Type: " + rstSchema.getField("TABLE_TYPE").getString()+"\n"); intRecordCount++; if ( intRecordCount == intDisplayRecords) { System.out.println("Press <Enter> to continue.."); in.readLine(); intRecordCount = 0; } rstSchema.moveNext(); } System.out.println("Press <Enter> to continue.."); in.readLine(); } catch(AdoException ae) { // Notify user of any errors that result from ADO. // As passing a Recordset, check for null pointer first. if(rstSchema != null) { PrintProviderError(rstSchema.getActiveConnection()); } else { System.out.println("Exception: " + ae.getMessage()); } } // System read requires this catch. catch(java.io.IOException je) { PrintIOError(je); } finally { // Cleanup Objects before exit. rstSchema.close(); cnn2.close(); // Cleanup objects before exit. if (rstSchema != null) if (rstSchema.getState() == 1) rstSchema.close(); if (cnn2 != null) if (cnn2.getState() == 1) cnn2.close(); } } // PrintProviderError Function static void PrintProviderError( Connection Cnn1 ) { // Print Provider errors from Connection object. // ErrItem is an item object in the Connections Errors collection. com.ms.wfc.data.Error ErrItem = null; long nCount = 0; int i = 0; nCount = Cnn1.getErrors().getCount(); // If there are any errors in the collection, print them. if( nCount > 0); { // Collection ranges from 0 to nCount - 1 for (i = 0; i< nCount; i++) { ErrItem = Cnn1.getErrors().getItem(i); System.out.println("\t Error number: " + ErrItem.getNumber() + "\t" + ErrItem.getDescription() ); } } } // PrintIOError Function static void PrintIOError( java.io.IOException je) { System.out.println("Error \n"); System.out.println("\tSource = " + je.getClass() + "\n"); System.out.println("\tDescription = " + je.getMessage() + "\n"); } } // EndOpenSchemaJ