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OdbcCommand.Prepare Method

Creates a prepared or compiled version of the command at the data source.

Namespace: System.Data.Odbc
Assembly: System.Data (in

public override void Prepare ()
public void Prepare ()
public override function Prepare ()
Not applicable.

Exception typeCondition


The Connection is not set.


The Connection is not .Data.Odbc.OdbcConnection.Open.

The Prepare method calls the ODBC SQLPrepare function. Depending on the capabilities of the underlying ODBC driver and data source, parameter information such as data types may be checked when the statement is prepared, if all parameters have been bound, or when it is executed if not all parameters have been bound. For maximum interoperability, an application should unbind all parameters that applied to a previous SQL statement before preparing a new SQL statement on the same OdbcCommand. This prevents errors that are caused by previous parameter information being applied to the new SQL statement.

If you call an Execute method after you call Prepare, any parameter value that is larger than the value specified by the .Data.Odbc.OdbcParameter.Size property is automatically truncated to the original specified size of the parameter, and no truncation errors are returned.

Output parameters (whether prepared or not) must have a user-specified data type. If you specify a variable length data type, you must also specify the maximum .Data.Odbc.OdbcParameter.Size.

Windows 98, Windows Server 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0, 1.1