Item, propriété – Exemple (VJ++)

S’applique à : Access 2013, Office 2013

Cet exemple montre comment la propriété Item accède aux membres d’une collection. L’exemple ouvre la table Authors de la base de données Pubs avec une commande paramétrable.

Le paramètre de la commande émise sur la base de données est accédé à partir de la collection Parameters de l’objet Command par index et par nom. Les champs de l'objet Recordset retourné sont ensuite accédés à partir de la collection Fields de cet objet par index et par nom.

 
// BeginItemJ 
import com.ms.wfc.data.*; 
import java.io.* ; 
import com.ms.com.*; 
 
public class ItemX 
{ 
 // The main entry point for the application. 
 
 public static void main (String[] args) 
 { 
 ItemX(); 
 System.exit(0); 
 } 
 
 // ItemX function 
 
 static void ItemX() 
 { 
 
 // Define ADO Objects. 
 Connection cnConn1 = null; 
 Recordset rstAuthors = null; 
 Command cmd = null; 
 Parameter prm = null; 
 Field fld = null; 
 
 // Declarations. 
 BufferedReader in = 
 new BufferedReader (new InputStreamReader(System.in)); 
 String strCnn = "Provider='sqloledb';Data Source='MySqlServer';" + 
 "Initial Catalog='Pubs';Integrated Security='SSPI';"; 
 Variant [] varColumn = null; 
 int intIndex; 
 int intLimit; 
 
 try 
 { 
 cnConn1 = new Connection(); 
 rstAuthors = new Recordset(); 
 cmd = new Command(); 
 
 // Set the array with the Authors table field (column) names. 
 varColumn = new Variant[9]; 
 varColumn[0] = new Variant("au_id"); 
 varColumn[1] = new Variant("au_lname"); 
 varColumn[2] = new Variant("au_fname"); 
 varColumn[3] = new Variant("phone"); 
 varColumn[4] = new Variant("address"); 
 varColumn[5] = new Variant("city"); 
 varColumn[6] = new Variant("state"); 
 varColumn[7] = new Variant("zip"); 
 varColumn[8] = new Variant("contract"); 
 
 cmd.setCommandText("SELECT * FROM Authors WHERE state = ?"); 
 prm = cmd.createParameter("ItemXparm", 
 AdoEnums.DataType.CHAR, 
 AdoEnums.ParameterDirection.INPUT, 
 2, 
 "CA"); 
 cmd.getParameters().append(prm); 
 
 cnConn1.open(strCnn); 
 cmd.setActiveConnection(cnConn1); 
 
 // Connection and CommandType are omitted 
 // because a Command Object is provided. 
 rstAuthors.open(cmd, 
 null , 
 AdoEnums.CursorType.STATIC, 
 AdoEnums.LockType.READONLY); 
 
 System.out.println( 
 "The Parameters collection accessed by index..."); 
 prm = cmd.getParameters().getItem(0); 
 System.out.println("Parameter name = '" + 
 prm.getName() + 
 "', value = '" + 
 prm.getValue().toString() + "'\n"); 
 
 System.out.println( 
 "The Parameters collection accessed by name..."); 
 prm = cmd.getParameters().getItem("ItemXparm"); 
 System.out.println("Parameters name = '" + 
 prm.getName() + 
 "', value = '" + 
 prm.getValue().toString() + "'\n"); 
 System.out.println("Press <Enter> to continue.."); 
 in.readLine(); 
 
 System.out.println( 
 "The Fields collection accessed by index..."); 
 rstAuthors.moveFirst(); 
 intLimit = rstAuthors.getFields().getCount() - 1; 
 for(intIndex = 0; intIndex <= intLimit; intIndex++) 
 { 
 fld = rstAuthors.getFields().getItem(intIndex); 
 short intVtType = fld.getValue().getvt(); 
 String strFieldValue; 
 switch(intVtType) 
 { 
 case Variant.VariantString : 
 strFieldValue = fld.getValue().toString(); 
 break; 
 case Variant.VariantBoolean : 
 if(fld.getValue().getBoolean()) 
 strFieldValue = "True"; 
 else 
 strFieldValue = "False"; 
 break; 
 default : 
 strFieldValue = fld.getValue().toString(); 
 break; 
 } 
 System.out.println("Field " + 
 Integer.toString(intIndex) + 
 " : Name = '" + 
 fld.getName() + 
 "', value = '" + 
 strFieldValue + 
 "'"); 
 } 
 System.out.println("\nPress <Enter> to continue.."); 
 in.readLine(); 
 
 System.out.println("The Fields collection accessed by name..."); 
 rstAuthors.moveFirst(); 
 for(intIndex = 0; intIndex <= 8; intIndex++) 
 { 
 fld = rstAuthors.getFields().getItem 
 (varColumn[intIndex].toString()); 
 short intVtType = fld.getValue().getvt(); 
 String strFieldValue; 
 switch(intVtType) 
 { 
 case Variant.VariantString : 
 strFieldValue = fld.getValue().toString(); 
 break; 
 case Variant.VariantBoolean : 
 if(fld.getValue().getBoolean()) 
 strFieldValue = "True"; 
 else 
 strFieldValue = "False"; 
 break; 
 default : 
 strFieldValue = fld.getValue().toString(); 
 break; 
 } 
 System.out.println("Field " + 
 "name = '" + 
 fld.getName() + 
 "', value = '" + 
 strFieldValue + 
 "'"); 
 } 
 System.out.println("\nPress <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 (rstAuthors != null) 
 { 
 PrintProviderError(rstAuthors.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 (rstAuthors != null) 
 if (rstAuthors.getState() == 1) 
 rstAuthors.close(); 
 if (cnConn1 != null) 
 if (cnConn1.getState() == 1) 
 cnConn1.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"); 
 } 
} 
// EndItemJ