25.2.7.27. mysql_stmt_store_result()
int mysql_stmt_store_result(MYSQL_STMT
*stmt)
Description
You must call mysql_stmt_store_result() for
every statement that successfully produces a result set
(SELECT, SHOW,
DESCRIBE, EXPLAIN), and
only if you want to buffer the complete result set by the
client, so that the subsequent
mysql_stmt_fetch() call returns buffered
data.
It is unnecessary to call
mysql_stmt_store_result() for other
statements, but if you do, it does not harm or cause any
notable performance problem. You can detect whether the
statement produced a result set by checking if
mysql_stmt_result_metadata() returns
NULL. For more information, refer to
Section 25.2.7.22, “mysql_stmt_result_metadata()”.
Note: MySQL doesn't by
default calculate
MYSQL_FIELD->max_length for all columns
in mysql_stmt_store_result() because
calculating this would slow down
mysql_stmt_store_result() considerably and
most applications doesn't need max_length.
If you want max_length to be updated, you
can call mysql_stmt_attr_set(MYSQL_STMT,
STMT_ATTR_UPDATE_MAX_LENGTH, &flag) to enable
this. See Section 25.2.7.3, “mysql_stmt_attr_set()”.
Return Values
Zero if the results are buffered successfully. Non-zero if an
error occurred.
Errors
-
CR_COMMANDS_OUT_OF_SYNC
Commands were executed in an improper order.
-
CR_OUT_OF_MEMORY
Out of memory.
-
CR_SERVER_GONE_ERROR
The MySQL server has gone away.
-
CR_SERVER_LOST
The connection to the server was lost during the query.
-
CR_UNKNOWN_ERROR
An unknown error occurred.
