Prepared statements provide performance advantages for statements that are used repeatedly. ODBC provides a full set of functions for using prepared statements.

For an introduction to prepared statements, see Preparing statements.

To execute a prepared SQL statement

1. Prepare the statement using SQLPrepare.

   For example, the following code fragment illustrates how to prepare an INSERT statement:

   SQLRETURN retcode; SQLHSTMT stmt; retcode = SQLPrepare( stmt, "INSERT INTO Departments ( DepartmentID, DepartmentName, DepartmentHeadID ) VALUES (?, ?, ?,)", SQL_NTS);

   In this example:

   • retcode   Holds a return code that should be tested for success or failure of the operation.

   • stmt   Provides a handle to the statement so that it can be referenced later.

   • ?   The question marks are placeholders for statement parameters.

2. Set statement parameter values using SQLBindParameter.

   For example, the following function call sets the value of the DepartmentID variable:

   SQLBindParameter( stmt, 1, SQL_PARAM_INPUT, SQL_C_SSHORT, SQL_INTEGER, 0, 0, &sDeptID, 0, &cbDeptID);

   In this example:

   • stmt   is the statement handle.

   • 1   indicates that this call sets the value of the first placeholder.

   • SQL_PARAM_INPUT   indicates that the parameter is an input statement.

   • SQL_C_SHORT   indicates the C data type being used in the application.

   • SQL_INTEGER   indicates SQL data type being used in the database.

     The next two parameters indicate the column precision and the number of decimal digits: both zero for integers.

   • &sDeptID   is a pointer to a buffer for the parameter value.

   • 0   indicates the length of the buffer, in bytes.

   • &cbDeptID   is a pointer to a buffer for the length of the parameter value.

3. Bind the other two parameters and assign values to sDeptId.

4. Execute the statement:

   retcode = SQLExecute( stmt);

   Steps 2 to 4 can be carried out multiple times.

5. Drop the statement.

   Dropping the statement frees resources associated with the statement itself. You drop statements using SQLFreeHandle.

For a complete sample, including error checking, see samples-dir\SQLAnywhere\ODBCPrepare\odbcprepare.cpp.

For more information about SQLPrepare, see  SQLPrepare in the Microsoft ODBC Programmer's Reference.