How Can I Execute Multiple Queries in a Single JDBC Statement?

Efficiently Executing Multiple JDBC Queries with a Single Statement

JDBC offers several methods for executing multiple SQL queries within a single statement, enhancing database interaction efficiency. One approach involves leveraging the allowMultiQueries connection property. This setting permits the execution of multiple semicolon-separated queries in a single call.

To enable this feature, include allowMultiQueries=true in your database URL:

<code class="language-java">String dbUrl = "jdbc:mysql:///test?allowMultiQueries=true";</code>

With this enabled, the execute() method can handle multiple queries. For instance:

<code class="language-java">String multiQuerySqlString = "SELECT * FROM table1; INSERT INTO table2 VALUES (1, 'value1');";
boolean hasMoreResultSets = stmt.execute(multiQuerySqlString);</code>

The hasMoreResultSets boolean indicates the presence of further result sets. Iterate through the results as needed:

<code class="language-java">while (hasMoreResultSets || stmt.getUpdateCount() != -1) {
    if (hasMoreResultSets) {
        ResultSet rs = stmt.getResultSet();
        // Process ResultSet data here
    } else {
        int queryResult = stmt.getUpdateCount();
        // Handle Data Manipulation Language (DML) statement results
    }
    hasMoreResultSets = stmt.getMoreResults();
}</code>

Another effective technique involves creating a stored procedure encompassing multiple queries. This procedure can then be invoked using a CallableStatement. Results are retrieved via multiple ResultSet objects.

<code class="language-java">String storedProcedure = "CALL multi_query()";
CallableStatement cstmt = con.prepareCall(storedProcedure);
boolean hasMoreResultSets = cstmt.execute();
while (hasMoreResultSets) {
    ResultSet rs = cstmt.getResultSet();
    // Process ResultSet data here
    hasMoreResultSets = cstmt.getMoreResults();
}</code>

Both the allowMultiQueries property and stored procedures provide efficient ways to execute multiple queries using a single JDBC statement, optimizing database operations.

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