How Can I Execute Multiple SQL Statements in a Single JDBC Statement?

Multiple Queries in a Single Statement Using JDBC

JDBC allows for the execution of multiple SQL statements in a single operation. This can be useful in situations where you need to perform multiple independent actions or update multiple tables within a single transaction.

Example Code:

Consider the following sample code, which emulates the behavior of the MySQL query you mentioned:

String sqlQuery = "SELECT * FROM TABLE; INSERT INTO TABLE;";
Statement statement = connection.createStatement();
statement.execute(sqlQuery);

Method 1: Connection Property

To enable the execution of multiple queries in a single statement, you can set the allowMultiQueries connection property to true. This instructs the JDBC driver to allow the execution of multiple queries separated by semicolons.

String url = "jdbc:mysql://localhost:3306/databaseinjection?allowMultiQueries=true";
Connection connection = DriverManager.getConnection(url, sqlUsername, sqlPassword);

Method 2: Stored Procedure

Alternatively, you can create a stored procedure in your database that encapsulates the multiple queries. Then, call the stored procedure from Java using a CallableStatement. This allows you to capture multiple ResultSet objects returned by the procedure.

// Create a stored procedure
String storedProcedure = "CREATE PROCEDURE multi_query() BEGIN SELECT * FROM TABLE; INSERT INTO TABLE; END;";
// Call the stored procedure
CallableStatement cstmt = connection.prepareCall("{call multi_query()}");
cstmt.execute();
// Retrieve result sets
while (cstmt.getMoreResults()) {
    ResultSet resultSet = cstmt.getResultSet();
    // Handle the result set here
}

Benefits of Multiple Queries:

• Reduced database round trips, potentially improving performance.
• Atomicity of transactions, ensuring all queries are executed successfully or rolled back.
• Easier management of complex SQL operations that involve multiple tables.

Note:

• Not all database systems support the execution of multiple queries in a single statement.
• It's important to handle potential exceptions and ensure that all queries are handled correctly.

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