How to Retrieve the Auto-Generated ID After an INSERT in JDBC?

Retrieving Auto-Generated IDs in JDBC

This guide demonstrates how to retrieve the automatically generated ID after an INSERT operation within a JDBC environment.

Steps:

1. Prepare the Statement: Create a PreparedStatement and explicitly enable the retrieval of generated keys using Statement.RETURN_GENERATED_KEYS.

   <code class="language-java">PreparedStatement statement = connection.prepareStatement(SQL_INSERT, Statement.RETURN_GENERATED_KEYS);</code>

2. Execute the INSERT: Execute the prepared statement to insert your data into the database.

   <code class="language-java">int affectedRows = statement.executeUpdate();</code>

3. Retrieve Generated Keys: Use statement.getGeneratedKeys() to obtain a ResultSet containing the generated keys. The first column of this ResultSet will typically hold the newly generated ID.

   <code class="language-java">try (ResultSet generatedKeys = statement.getGeneratedKeys()) {
       if (generatedKeys.next()) {
           user.setId(generatedKeys.getLong(1));
       }
   }</code>

4. Exception Handling: Wrap your JDBC code in a try-catch block to handle potential SQLExceptions.

   <code class="language-java">try {
       // JDBC code from steps 1-3
   } catch (SQLException e) {
       // Handle the exception appropriately (e.g., log the error, throw a custom exception)
   }</code>

Important Considerations:

The behavior of Statement.getGeneratedKeys() can be database and JDBC driver specific. Ensure your driver supports this functionality and that your database is configured to auto-generate IDs.

The above is the detailed content of How to Retrieve the Auto-Generated ID After an INSERT in JDBC?. For more information, please follow other related articles on the PHP Chinese website!