Data-at-Execution Parameter Limitations

If you use a data-at-execution parameter to send more than 65,535 bytes of data (for SQL Server 4.21a) or 250K of data (for SQL Server version 6.0 and later) for a SQL_LONGVARCHAR (text) or SQL_LONGVARBINARY (image) column, the parameter is subject to the following restrictions:

• It can be used only as an insert_value in an INSERT statement.
• It can be used only as an expression in the SET clause of an UPDATE statement.
• It cannot be used in a statement with data-at-execution parameters that have a datatype other than SQL_LONGVARCHAR or SQL_LONGVARBINARY.
• It can be used in a statement with non-data-at-execution parameters of any datatype.
• If its value is NULL, the cbColDef argument in SQLBindParameter and the cbValueMax argument in SQLPutData must be SQL_NULL_DATA.
• Canceling the operation (a call to SQLPutData for a column after SQLParamData returns SQL_NEED_DATA) before completion will cause a partial update. The text or image column you were processing when you canceled will be set to an intermediate "place holder" value, and any unprocessed text or image columns will remain unchanged.