The docs for multi_query
say:
Returns FALSE if the first statement failed. To retrieve subsequent errors from other statements you have to call mysqli_next_result() first.
The docs for next_result
say:
Returns TRUE on success or FALSE on failure.
Finally, the example posted in the docs for multi_query
use the return value from next_result
to determine when there are no more queries; e.g. to stop looping:
<?php $mysqli = new mysqli("localhost", "my_user", "my_password", "world"); /* check connection */ if (mysqli_connect_errno()) { printf("Connect failed: %sn", mysqli_connect_error()); exit(); } $query = "SELECT CURRENT_USER();"; $query .= "SELECT Name FROM City ORDER BY ID LIMIT 20, 5"; /* execute multi query */ if ($mysqli->multi_query($query)) { do { /* store first result set */ if ($result = $mysqli->store_result()) { while ($row = $result->fetch_row()) { printf("%sn", $row[0]); } $result->free(); } /* print divider */ if ($mysqli->more_results()) { printf("-----------------n"); } } while ($mysqli->next_result()); // <-- HERE! } /* close connection */ $mysqli->close(); ?>
I don’t know the number of queries provided, nor do I know anything about the SQL that I’m going to execute. I therefore can’t just compare the number of queries against the number of returned results. Yet I want to display an error message to the user if, say, the third query was the broken query. But I don’t seem to have a way to tell if next_result
failed because there were no more queries to execute, or if it’s because there was an error in the SQL syntax.
How can I check all the queries for errors?
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Answer
Despite the code example in the docs, perhaps the better method would be something like this:
if ($mysqli->multi_query(...)) { do { // fetch results if (!$mysqli->more_results()) { break; } if (!$mysqli->next_result()) { // report error break; } } while (true); }