UpdateBatch 和 CancelBatch 方法示例 (VJ++)

适用于:Access 2013、Office 2013

以下示例演示了如何结合使用 UpdateBatch 方法和 CancelBatch 方法。

 
// BeginUpdateBatchJ 
import java.io.*; 
import com.ms.wfc.data.*; 
 
public class UpdateBatchX 
{ 
 // The main entry point of the application. 
 public static void main (String[] args) 
 { 
 UpdateBatchX(); 
 System.exit(0); 
 } 
 // UpdateBatchX Function 
 
 static void UpdateBatchX() 
 { 
 // Define ADO Objects. 
 Recordset rstTitles = null; 
 
 // Declarations. 
 String strCnn = "Provider='sqloledb';Data Source='MySqlServer';"+ 
 "Initial Catalog='Pubs';Integrated Security='SSPI';"; 
 String strTitle; 
 String strMessage; 
 BufferedReader in = 
 new BufferedReader(new InputStreamReader(System.in)); 
 
 try 
 { 
 rstTitles = new Recordset(); 
 rstTitles.setCursorType(AdoEnums.CursorType.KEYSET); 
 rstTitles.setLockType(AdoEnums.LockType.BATCHOPTIMISTIC); 
 rstTitles.open("Titles", strCnn, AdoEnums.CursorType.KEYSET, 
 AdoEnums.LockType.BATCHOPTIMISTIC, 
 AdoEnums.CommandType.TABLE); 
 
 rstTitles.moveFirst(); 
 
 // Loop through recordset and ask user if she wants 
 // to change the type for the specified table. 
 while(!rstTitles.getEOF()) 
 { 
 if(rstTitles.getField("Type").getString(). 
 trim().equalsIgnoreCase("psychology")) 
 { 
 strTitle = rstTitles.getField("Title").getString(); 
 strMessage = "Title: "+ strTitle + "\n" + 
 "Change type to self_help?Enter (Y/N)"; 
 System.out.println(strMessage); 
 if(in.readLine().trim().equalsIgnoreCase("Y")) 
 rstTitles.getField("type").setString("self_help"); 
 } 
 rstTitles.moveNext(); 
 } 
 // Ask the user if she wants to commit to all the 
 // changes made above. 
 System.out.println("Save all changes?Enter (Y/N)"); 
 if(in.readLine().trim().equalsIgnoreCase("Y")) 
 rstTitles.updateBatch(); 
 else 
 rstTitles.cancelBatch(); 
 
 // Print current data in recordset. 
 rstTitles.requery(); 
 rstTitles.moveFirst(); 
 while(!rstTitles.getEOF()) 
 { 
 System.out.println(rstTitles.getField("title").getString() + 
 " - " + rstTitles.getField("type").getString()); 
 rstTitles.moveNext(); 
 } 
 
 // Restore original values because this is a demonstration. 
 rstTitles.moveFirst(); 
 while(!rstTitles.getEOF()) 
 { 
 if(rstTitles.getField("type").getString(). 
 trim().equalsIgnoreCase("self_help")) 
 rstTitles.getField("type").setString("psychology"); 
 rstTitles.moveNext(); 
 } 
 rstTitles.updateBatch(); 
 
 System.out.println("Press <Enter> to continue.."); 
 in.readLine(); 
 
 } 
 catch(AdoException ae) 
 { 
 // Notify the user of any errors that result from ADO. 
 
 // As passing a recordset, check for null pointer first. 
 if(rstTitles != null) 
 { 
 PrintProviderError(rstTitles.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 (rstTitles != null) 
 if (rstTitles.getState() == 1) 
 rstTitles.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("\t Source: " + je.getClass() + "\n"); 
 System.out.println("\t Description: "+ je.getMessage() + "\n"); 
 } 
} 
// EndUpdateBatchJ