JDBC事务，sql语句的执行顺序 [英] JDBC transaction, execution order of sql statements

问题描述

我有以下JDBC代码:

Connection conn = connectUserDataSource();
        // Setting auto commit to false to execute all queries as part of transaction
        conn.setAutoCommit(false);
        PreparedStatement deletePreparedStatement = null;
        PreparedStatement insertPreparedStatement = null;
        try
        {
            deletePreparedStatement = conn.prepareStatement(sqlDelete);
            deletePreparedStatement.setInt(1, someId);
            deletePreparedStatement.executeUpdate();

            insertPreparedStatement = conn.prepareStatement(sqlInsert);
            for(SomeObject obj : objects)
            {
                insertPreparedStatement.setInt(1, obj.getId());
            }

            insertPreparedStatement.executeBatch();
            // committing transaction
            conn.commit();
            transactionComplete = true;
        }

我希望2条准备好的语句成为一个JDBC事务的一部分.我想知道创建它们的顺序是否会是SQL语句的执行顺序:先删除，然后在插入-.

解决方案

它们是从上到下执行的，因此按照您执行的顺序，删除将首先执行，插入之后.

I have following JDBC code:

Connection conn = connectUserDataSource();
        // Setting auto commit to false to execute all queries as part of transaction
        conn.setAutoCommit(false);
        PreparedStatement deletePreparedStatement = null;
        PreparedStatement insertPreparedStatement = null;
        try
        {
            deletePreparedStatement = conn.prepareStatement(sqlDelete);
            deletePreparedStatement.setInt(1, someId);
            deletePreparedStatement.executeUpdate();

            insertPreparedStatement = conn.prepareStatement(sqlInsert);
            for(SomeObject obj : objects)
            {
                insertPreparedStatement.setInt(1, obj.getId());
            }

            insertPreparedStatement.executeBatch();
            // committing transaction
            conn.commit();
            transactionComplete = true;
        }

And I would like 2 prepared statements to be part of one JDBC transaction. I am wondering whether order at which they are created will be the execution order of SQL statements: delete first and inserts - after.

解决方案

They are executed from top to bottom, so in the order you did it, the deletes will execute first and the insert after them.

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