MySQL PreparedStatement: Why is `executeQuery()` Failing with a Syntax Error?

MySQL Prepared Statement: Resolving executeQuery() Syntax Errors

A common issue when using Java's PreparedStatement with MySQL involves SQLException errors indicating SQL syntax problems near the placeholder (?). This often arises from incorrectly executing the statement.

The Problem:

Java code employing PreparedStatement might throw an exception similar to:

<code>... you have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '?'</code>

The Incorrect Approach:

The error typically occurs when attempting to execute the PreparedStatement using executeQuery() with a string argument (e.g., the SQL query itself):

<code class="language-java">statement.executeQuery(searchPerson); // Incorrect</code>

This treats searchPerson as a literal SQL string, ignoring the placeholders set within the PreparedStatement.

The Correct Solution:

The key is to execute the PreparedStatement without any parameters passed to executeQuery():

<code class="language-java">statement.executeQuery(); // Correct</code>

The parameters are already bound to the PreparedStatement using setString(), setInt(), etc., before the executeQuery() call. Providing the query string again as an argument overrides this binding and leads to the syntax error. executeQuery() simply executes the statement with the pre-bound parameters.

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