What Causes the \'Commands out of Sync\' Error in MySQL (#2014)?

MySQL Error #2014: Understanding "Commands out of Sync"

When attempting to execute a stored procedure, you may encounter the enigmatic error message "#2014 - Commands out of sync; you can't run this command now." This error highlights a fundamental misunderstanding in the order of command execution.

Delving into the Error

The MySQL reference manual clarifies the "Commands out of sync" error in section B.3.2.12:

If you get Commands out of sync; you can't run this command now in your client code, you are calling client functions in the wrong order.

This error arises when you attempt to execute client functions in an incorrect sequence. For instance, using mysql_use_result() followed by another query without calling mysql_free_result(). Additionally, executing multiple data-returning queries without invoking mysql_use_result() or mysql_store_result() can trigger this error.

Resolving the Error

The solution lies in ensuring the correct order of function calls. Avoid using mysql_use_result() unless absolutely necessary. Alternatively, consider using mysql_store_result() instead.

Tool-Related Issues

In some cases, the "Commands out of sync" error can be attributed to the tool you're using. A post on the MySQL forums suggests that using MySQL-Fron instead of MySQL Query Browser can alleviate the problem. This implies that the issue could stem from the specific interface rather than the server or database itself.

By understanding the root cause of the "Commands out of sync" error, you can modify your approach and ensure seamless execution of your stored procedures.

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