Question

我有一个无法运行的SQL事务查询。请问任何人请告诉我为什么？我也无法使用preparedstament.executequery();运行它。

START TRANSACTION;
SELECT total_installment_remaining  FROM payment_loan WHERE loan_id = 1 FOR UPDATE;
UPDATE payment_loan SET total_installment_remaining =total_installment_remaining-1 WHERE loan_id = 1;
COMMIT;

Answer 1

关闭自动提交，然后使用Connection.commit()结束交易。

connection.setAutocommit(false);
Statement stmt = con2.createStatement();

// this will automatically start a transaction
ResultSet rs = stmt.executeQuery("SELECT total_installment_remaining  FROM payment_loan WHERE loan_id = 1 FOR UPDATE");

// process the result if needed
...

stmt.executeUpdate("UPDATE payment_loan SET total_installment_remaining =total_installment_remaining-1 WHERE loan_id = 1");

// end the transaction and persist then changes
connection.commit();

如果您不需要代码中的SELECT结果，那么您首先不需要SELECT ... FOR UPDATE，因为UPDATE会锁定无论如何。

Answer 2

String query = "START TRANSACTION;SELECT total_installment_remaining  FROMpayment_loan WHERE loan_id = 1 FOR UPDATE;UPDATE payment_loan SET total_installment_remaining =total_installment_remaining-1 WHERE loan_id = 1;COMMIT;";
    try {
        ps2 = con2.prepareStatement(query);
        ResultSet rs2 = ps2.executeQuery();
        while (rs2.next()) {
            rs2.getInt(1);
        }
        // rs.close();
        // con.close();
    } catch (SQLException e) {
        logger.error("",e);
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

如何在PreparedStatement中运行SQL TRANSACTION

2 个答案: