Creates a prepared (or compiled) version of the command on the data source.
Assembly: System.Data (in System.Data.dll)
Before you call , specify the data type of each parameter in the statement to be prepared. For each parameter that has a variable length data type, you must set the Size property to the maximum size needed. returns an error if these conditions are not met.
If you call an Execute method after you call , any parameter value that is larger than the value specified by the 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 Size.
The following example creates an OleDbCommand and opens the connection. The example then prepares a stored procedure on the data source by passing a string that is an SQL SELECT statement and a string to use to connect to the data source.