MySQL :: MySQL 8.4 C API Developer Guide :: 7.4.8 mysql_store_result_nonblocking() (original) (raw)

7.4.8 mysql_store_result_nonblocking()

enum net_async_status
mysql_store_result_nonblocking(MYSQL *mysql,
                               MYSQL_RES **result)

Description

Note

mysql_store_result_nonblocking() is an asynchronous function. It is the counterpart of themysql_store_result() synchronous function, for use by applications that require asynchronous communication with the server. For general information about writing asynchronous C API applications, see Chapter 7, C API Asynchronous Interface.

mysql_store_result_nonblocking() is used similarly tomysql_store_result(). For details about the latter, seeSection 5.4.84, “mysql_store_result()”. The two functions differ as follows:

• mysql_store_result() returns a pointer to a MYSQL_RESULT value that contains the result set, orNULL if there is no result set or an error occurred.
• mysql_store_result_nonblocking() returns an enum net_async_status status indicator and takes a second result argument that is the address of a pointer to aMYSQL_RESULT into which to store the result set. When the return status isNET_ASYNC_COMPLETE, theresult argument isNULL if there is no result set or an error occurred.

mysql_store_result_nonblocking() was added in MySQL 8.0.16.

Return Values

Returns an enum net_async_status value. See the description inSection 7.2, “C API Asynchronous Interface Data Structures”. ANET_ASYNC_ERROR return status indicates an error.

When the return status isNET_ASYNC_COMPLETE, theresult argument is NULL if there is no result set or an error occurred. To determine whether an error occurred, check whethermysql_error() returns a nonempty string, mysql_errno() returns nonzero, ormysql_field_count() returns zero.

Example

See Chapter 7, C API Asynchronous Interface.