With the attribute, the consumer needed to set it even if only one of many stored procedures being executed by the ADO application returned a rowset. Execute ' It is a good idea to disable the property after execute as the ' same command object may be used for a different SQL statement obj Cmd. The use of this property should be limited to SQL statements containing parameters of N data type as setting it incurs a processing overhead of at least one round-trip to the database. This property should be set to Dim obj Con As NEW ADODB. This property provides a way to selectively add statements to the cache when statement caching is enabled. ' Statement caching is enabled by setting the 'Stmt Cache Size' ' connection string attribute to a value greater than zero obj Con. The stored procedure or function being called could be either standalone or packaged. To see performance gains from metadata caching, Oracle recommends caching only those statements that are executed repeatedly. In addition, these operations cannot be undone with the . Open "select ename, dname " & _ "from emp, dept " & _ "where emp.deptno = dept.deptno", _ obj Con, ad Open Static, ad Lock Optimistic, ad Cmd Text 'Recordset created is updatable. Create Parameter("p Date", ad Date, ad Param Input) obj Cmd. When used with SQL Server Integration Services (SSIS), this allows an application to perform a fast-load to an OLE DB Destination using Oracle Provider for OLE DB.The use of this property should provide a performance boost to applications making use of the attribute previously. By default, this property is set to Dim obj Con As NEW ADODB. By default, the property is set to Dim obj Con As NEW ADODB. Connection String = "Stmt Cache Size=10; Data Source=My Ora Db;" & _ "User ID=scott; Password=tiger;" obj Con. However, the CREATE OR REPLACE PACKAGE Employees AS TYPE empcur IS REF CURSOR; PROCEDURE Get Emp Records(p_cursor OUT empcur, q_cursor OUT empcur, indeptno IN NUMBER, p_errorcode OUT NUMBER); FUNCTION Get Dept(inempno IN NUMBER, p_errorcode OUT NUMBER) RETURN empcur; END Employees; CREATE OR REPLACE PACKAGE BODY Employees AS PROCEDURE Get Emp Records(p_cursor OUT empcur, q_cursor OUT empcur, indeptno IN NUMBER, p_errorcode OUT NUMBER) IS BEGIN p_errorcode := 0; OPEN p_cursor FOR SELECT * FROM emp WHERE deptno = indeptno ORDER BY empno; OPEN q_cursor FOR SELECT empno FROM emp WHERE deptno = indeptno ORDER BY empno; EXCEPTION WHEN OTHERS THEN p_errorcode:= SQLCODE; END Get Emp Records; FUNCTION Get Dept(inempno IN NUMBER, p_errorcode OUT NUMBER) RETURN empcur IS p_cursor empcur; BEGIN p_errorcode := 0; OPEN p_cursor FOR SELECT deptno FROM emp WHERE empno = inempno; RETURN (p_cursor); EXCEPTION WHEN OTHERS THEN p_errorcode:= SQLCODE; END Get Dept; END Employees; Dim Con As New ADODB. method cancels the Ora OLEDB command currently being executed. Rowsets created using queries with joins are updatable by Ora OLEDB only with the Client Cursor Engine enabled. Please note that Cursor Location 'needs to be explicitly set to ad Use Client for this join recordset 'to be updatable. Oracle; User ID=scott;" & _ "Password=tiger; Data Source=My Ora DB;" & _ "Fetch Size=200; Cache Type=File;" con. This behavior occurs because Ora OLEDB does not perform explicit locks on the rows being modified. This can dramatically speed up load times versus using a conventional load.To connect to a specific database, the consumer is required to set the following properties of the Ora OLEDB is compatible with OLE DB Services that are available in OLE DB version 2.0 and later.OLE DB Services contains useful services such as automatic transaction enlistment, Client Cursor Engine (CCE), connection and session pooling, which can enhance application performance, and others.Sessions enabled for distributed transaction enlistments cannot run statements that use the direct path load and parallel DML capabilities of the Oracle database.Such statements are executed as conventional path serial statements.Example: Setting the Custom Property PLSQLRSet Dim obj Res As NEW ADODB. This method can be useful when the application needs to cancel a long running command during times of heavy network traffic or heavy server use. C/C OLE DB consumers must enable this service to make these rowsets updatable. , only the explicitly provided values for insert and update operations are returned when column values are requested for those rows. However, when new data is submitted to the database, the database only performs the update if the rowset data was not already updated by another user, which means that dirty writes are not allowed. In Visual Basic, date formats are controlled by the Regional Settings properties in Windows Control Panel. In order to perform a fast-load, set the column, the time zone setting of the client is used.
If Oracle-specific connection string attributes are not provided at connection time, then the default registry values are used.
Ora OLEDB also supports returning rowsets from PL/SQL stored procedures and functions. For Oracle Provider for OLE DB, if the Private Sub Command1_Click() Dim obj Con As New ADODB. For insert operations, the default time zone from the client session is added to the is used. Oracle.1; User ID=user_name;"& _ "Password=pwd; Data Source=Oracle;" con. Open "select * from test_table2", con, ad Open Dynamic, ad Lock Optimistic rec.
By default, ADO creates a nonupdatable rowset from a command object. TIMESTAMP Column Insert Data: 4/16/2003 AM (No time zone) Data in DB: 4/16/2003 .000000 AM Data Retrieval: 4/16/2003 AM TIMESTAMP WITH TIME ZONE Column Insert Data: 4/16/2003 AM (Time zone of the Client session is used) Data in DB: 4/16/2003 .000000 AM - Data Retrieval: 4/16/2003 AM (Time zone is dropped) , which is the same as US PDT (Pacific daylight time). Open "select timestamp_column from test_table", con, ad Open Dynamic,_ ad Lock Optimistic rec. Open 'no restriction on using ad Use Server or ad Use Client rec. Add New Array("year_to_month_column", "day_to_second_column"), _ Array("8-1", "3 .12") 'update data rec.
After all references to the session object are released, the session object is removed from memory and the connection is dropped. Properties ("PLSQLRSet") = TRUE ' Stored Procedures returning resultsets must be called using the ' ODBC escape sequence for calling stored procedures. Command Text = "" ' Get the first recordset Set Rst1 = Cmd. Properties("PLSQLRSet") = FALSE ' Get the second recordset Set Rst2 = Rst1. However, if the literal values in the statements are different, the parsed information cannot be reused unless the subsequent statements also have the same literal values.
Ora OLEDB supports local and distributed transactions, which provide explicit commit and abort transactional operations. In addition, a local transaction cannot be started if the session is currently enlisted in a distributed transaction. Create Parameter("Prm2", ad Small Int, ad Param Output) Cmd. Next Recordset ' Just as in a stored procedure, the REF CURSOR return value must ' not be bound in a stored function. Stmt Cache Size Connection String Attribute This attribute enables or disables Ora OLEDB statement caching.