博客

通过JDBC查询数据库时出现了以下报错

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'user_role.user_id = 1' at line 1

检查语法是没有问题的，但是忽略了一点。

            var selectionStatement = connection.prepareStatement(
                    "SELECT role.role_name AS roleName from user_role" +
                            " INNER JOIN role on user_role.role_id= role.id"+
                            "WHERE user_role.user_id = ?"
            );

原来是代码中SQL语句拼接时，WHERE关键字前面没有加空格导致与前面的字符串混在一起。修改后解决报错问题。

            var selectionStatement = connection.prepareStatement(
                    "SELECT role.role_name AS roleName from user_role" +
                            " INNER JOIN role on user_role.role_id= role.id"+
                            " WHERE user_role.user_id = ?"
            );