execute-command.md

Execute a command

All methods introduced in the create a command and fetch data deal with SELECT queries which fetch data from databases.

For queries that don't return any data, you should call the Yiisoft\Db\Command\CommandInterface::execute() method:

• If the query is successful, Yiisoft\Db\Command\CommandInterface::execute() will return the number of rows affected by the command execution.
• If no rows were affected by the command execution, it returns 0.
• If the query fails, it throws a Yiisoft\Db\Exception\Exception.

Let's say there is a customer table, with row having 1 id is present and row having 1000 id is missing. And non-SELECT queries are being executed for both of them.

Then, in the following code affected row count will be 1, because the row has been found and successfully updated:

use Yiisoft\Db\Connection\ConnectionInterface;

/** @var ConnectionInterface $db */

$command = $db->createCommand("UPDATE {{%customer}} SET [[name]] = 'John Doe' WHERE [[id]] = 1");
$rowCount = $command->execute(); // 1

This query however affects no rows, because no rows were found by the given condition in WHERE clause:

use Yiisoft\Db\Connection\ConnectionInterface;

/** @var ConnectionInterface $db */

$command = $db->createCommand("UPDATE {{%customer}} SET [[name]] = 'John Doe' WHERE [[id]] = 1000");
$rowCount = $command->execute(); // 0

In case of invalid SQL, the according exception will be thrown.

use Yiisoft\Db\Connection\ConnectionInterface;

/** @var ConnectionInterface $db */

$db->createCommand('bad SQL')->execute();