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Allocating ODBC handles

The handle types required for ODBC programs are as follows:

To use an ODBC handle

1. Call the SQLAllocHandle function.

   SQLAllocHandle takes the following parameters:

   • an identifier for the type of item being allocated

   • the handle of the parent item

   • a pointer to the location of the handle to be allocated

     For a full description, see  SQLAllocHandle in the Microsoft ODBC Programmer's Reference.

2. Use the handle in subsequent function calls.

3. Free the object using SQLFreeHandle.

   SQLFreeHandle takes the following parameters:

   • an identifier for the type of item being freed

   • the handle of the item being freed

     For a full description, see  SQLFreeHandle in the Microsoft ODBC Programmer's Reference.

The following code fragment allocates and frees an environment handle:

SQLHENV env;
SQLRETURN retcode;
retcode = SQLAllocHandle( 
      SQL_HANDLE_ENV, 
      SQL_NULL_HANDLE, 
      &env ); 
if( retcode == SQL_SUCCESS 
    || retcode == SQL_SUCCESS_WITH_INFO ) {
  // success: application Code here
}
SQLFreeHandle( SQL_HANDLE_ENV, env );

For more information about return codes and error handling, see Handling errors.