Argument Value Checks

The Driver Manager checks the following types of arguments. Unless otherwise noted, the Driver Manager returns SQL_ERROR for errors in argument values.

• Environment, connection, and statement handles usually cannot be null pointers. The Driver Manager returns SQL_INVALID_HANDLE when it finds a null handle.
  
  
• Required pointer arguments, such as OutputHandlePtr in SQLAllocHandle and CursorName in SQLSetCursorName, cannot be null pointers.
  
  
• Option flags that do not support driver-specific values must be a legal value. For example, Operation in SQLSetPos must be SQL_POSITION, SQL_REFRESH, SQL_UPDATE, SQL_DELETE, or SQL_ADD.
  
  
• Option flags must be supported in the version of ODBC supported by the driver. For example, InfoType in SQLGetInfo cannot be SQL_ASYNC_MODE (introduced in ODBC 3.0) when calling an ODBC 2.0 driver.
  
  
• Column and parameter numbers must be greater than 0 or greater than or equal to 0, depending on the function. The driver must check the upper limit of these argument values based on the current result set or SQL statement.
  
  
• Length/indicator arguments and data buffer length arguments must contain appropriate values. For example, the argument that specifies the length of a table name in SQLColumns (NameLength3) must be SQL_NTS or a value greater than 0; BufferLength in SQLDescribeCol must be greater than or equal to 0. The driver might also need to check these arguments. For example, it might check that NameLength3 is less than or equal to the maximum length of a table name in the data source.