When processing a result set, there are four ways for an application to retrieve a result item’s value:
It calls ct_bind to associate a result item with a program variable. When the program calls ct_fetch to fetch a result row, the item’s value is automatically converted to the destination variable’s format and the result is placed into the bound destination variable. Most applications use this method for all result items except large text or image values. See “text and image data handling” for more information.
It calls ct_get_data to retrieve a result item’s value in chunks. After calling ct_fetch to fetch the row, the application calls ct_get_data in a loop. Each ct_get_data call retrieves a chunk of the result item’s value. Most applications use ct_get_data only to retrieve large text or image values.
It calls ct_dyndesc(CS_USE_DESC) to associate a dynamic descriptor with the result set. After a dynamic descriptor is associated with a result set, an application repeatedly calls ct_fetch to fetch each row, and for each row, calls ct_dyndesc once for each result item. Typical applications do not use ct_dyndesc, which is intended for precompiler support.
It calls ct_dynsqlda(CS_USE_DESC) to associate an application-managed SQLDA structure with the result columns. An application calls ct_dynsqlda once to bind all result columns to the value buffers pointed at by the SQLDA structure. Subsequent calls to ct_fetch place column values in the value buffers. Typical applications do not use ct_dynsqlda, which is intended for precompiler support.
