How to: Use Data-at-Execution Columns (ODBC)

新增： 2006 年 4 月 14 日

To use data-at-execution text, ntext, or image columns

For each data-at-execution column, put special values into the buffers previously bound by SQLBindCol:
- For the last parameter, use SQL_LEN_DATA_AT_EXEC(length) where length is the total length of the text, ntext, or image column data in bytes.
- For the fourth parameter, put a program-defined column identifier.
Calling SQLSetPos returns SQL_NEED_DATA, which indicates that data-at-execution columns are ready for processing.
For each data-at-execution column:
- Call SQLParamData to get the column array pointer. It will return SQL_NEED_DATA if there is another data-at-execution column.
- Call SQLPutData one or more times to send the column data, until length is sent.
Call SQLParamData to indicate that all the data for the final data-at-execution column is sent. It will not return SQL_NEED_DATA.