Question

class User {

public static void main(String arg[]) throws SQLException {
    Connection con = DBConnect.getConnection();
    con.setAutoCommit(false);
    PreparedStatement pstmt;
    System.out.println(con.getMetaData().supportsSavepoints()); // true
    try {
        pstmt = con.prepareStatement("insert into emp(emp_id, emp_name, salary, address, contact_number)values(?,?,?,?,?)");
        pstmt.setInt(1, 1);
        pstmt.setString(2, "a");
        pstmt.setDouble(3, 8);
        pstmt.setString(4, "s");
        pstmt.setInt(5, 9);
        pstmt.executeUpdate();
        con.commit();
        Savepoint sp = con.setSavepoint();
        if (myMethod(con)) {
            /**
             * I want to rollback the nested transaction if any error occur
             */
            con.rollback(sp);
        }
    } catch (SQLException e) {
        e.printStackTrace();
    }
}

public static boolean myMethod(Connection con) throws SQLException {

    PreparedStatement pstmt;
    try {
        pstmt = con.prepareStatement("insert into emp(emp_id, emp_name, salary, address, contact_number)values(?,?,?,?,?)");
        pstmt.setInt(1, 2);
        pstmt.setString(2, "G");
        pstmt.setDouble(3, 8);
        pstmt.setString(4, "G");
        pstmt.setInt(5, 10);
        pstmt.executeUpdate();
        con.commit();
    } catch (SQLException e) {
        e.printStackTrace();
    }
    return true;
}

}

在上面的代码中，如果任何条件失败，我想回滚嵌套事务。我在提交第一个事务后创建了一个保存点。我得到了一个异常

java.sql.SQLException: SAVEPOINT _667166fe_13ab4b3e3de__8000 does not exist
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:2928)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1571)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:1666)
at com.mysql.jdbc.Connection.execSQL(Connection.java:2988)
at com.mysql.jdbc.Statement.executeUpdate(Statement.java:935)
at com.mysql.jdbc.Statement.executeUpdate(Statement.java:873)
at com.mysql.jdbc.Connection.rollback(Connection.java:4777)
at com.User.main(User.java:31)

我想知道嵌套事务是否会回滚？

Answer 1

由于您之前和之后（在myMethod（）方法中）con.commit();已经调用Savepoint sp = con.setSavepoint();，因此没有savepoint因此抱怨。

COMMIT removes all the save points.请参阅此处的文档：

Oracle SAVEPOINT Statement
SQLite Save Point

如果要设置保存点，请删除commit来电。

在代码的当前状态下，如果成功提交了所有事务，则无法回滚。

“java.sql.SQLException：SAVEPOINT _667166fe_13ab4b3e3de__8000不存在”嵌套事务回滚中发生异常？

1 个答案: