How to get rid of MySQL error 'Prepared statement needs to be re-prepared'
This is a possibility: MySQL bug #42041
They suggest upping the value of table_definition_cache
.
You can read about statement caching in the MySQL docs.
@docwhat's answer seems nice, but on a shared hosting server, not everyone is allowed to touch the table_open_cache
or table_definition_cache
options.
Since this error is related to prepared statements, I have tried to 'emulate' those with PDO by providing the following option:
$dbh = new PDO('mysql:host=localhost;dbname=test', $user, $pass, [
PDO::ATTR_EMULATE_PREPARES => true
]);
Note: actually this is in a Laravel 5.6 project, and I added the option in config/database.php
:
'connections' => [
'mysql' => [
'driver' => 'mysql',
'host' => env('DB_HOST', '127.0.0.1'),
'port' => env('DB_PORT', '3306'),
'database' => env('DB_DATABASE', 'forge'),
'username' => env('DB_USERNAME', 'forge'),
'password' => env('DB_PASSWORD', ''),
'unix_socket' => env('DB_SOCKET', ''),
'charset' => 'utf8mb4',
'collation' => 'utf8mb4_unicode_ci',
'prefix' => '',
'strict' => true,
'engine' => null,
'options' => [
PDO::ATTR_EMULATE_PREPARES => true,
],
],
(...)
],
I have not tested the impact of emulating prepared statements on the duration of loading my site, but it works against the error SQLSTATE[HY000]: General error: 1615 Prepared statement needs to be re-prepared
I got.
Update on the performance: the emulated version seems to be slightly faster (32.7±1.4ms emulated, 35.0±2.3ms normal, n=10, p-value=0.027 for two-tailed Student's T-test).