mysql：当我执行下面提到的事情时е
整数值不正确：'。42 . ' 对于第1行的“user\u id”列）
此错误并且无法插入记录为什么会发生这种情况？

CREATE TABLE `test` (
       `uid` INT PRIMARY KEY AUTO_INCREMENT,
        `uname` VARCHAR(25) NOT NULL,
         `urole` VARCHAR(25) NOT NULL,
         `udesig` VARCHAR(25) NOT NULL,
    `usalary` INT(6) NOT NULL

     );

CREATE TABLE `audit_trail_test` (
         `_id` INT PRIMARY KEY AUTO_INCREMENT,
         `_group_id` INT(5) NOT NULL,
         `uid` INT NOT NULL,
           `uname` VARCHAR(25) NOT NULL,
         `urole` VARCHAR(25) NOT NULL,
         `udesig` VARCHAR(25) NOT NULL,
         `usalary` INT(6) NOT NULL

     );
CREATE TABLE `audit_trail_revisions` (
         `id` INT PRIMARY KEY AUTO_INCREMENT,
         `user_id` INT NOT NULL,
         `time` DATETIME NOT NULL
     );

DELIMITER $$
CREATE PROCEDURE create_revision_record()
     BEGIN
        IF @group_id IS NULL THEN
             INSERT INTO `audit_trail_revisions`
                 (user_id, `time`)
                     VALUES
                 (@user_id, @time);
            SET @group_id = LAST_INSERT_ID();
        END IF;
     END;

     CREATE TRIGGER `test_insert` AFTER INSERT ON `test`
         FOR EACH ROW BEGIN
             CALL create_revision_record();
             INSERT INTO `audit_trail_test`
                 (
                     uid,
                     uname,
     urole,
     udesig,
     usalary,
                     _group_id
                 )
            VALUES
                 (
                     NEW.uid,
                     NEW.uname,
     NEW.urole,
     NEW.udesig,
     NEW.usalary,
                     @group_id
                );
         END;
     $$

CREATE TRIGGER `test_update` AFTER UPDATE ON `test`
         FOR EACH ROW BEGIN
             CALL create_revision_record();
             INSERT INTO `audit_trail_test`
                 (
                     uid,
                     uname,
     urole,
     udesig,
     usalary ,
                    _group_id
                 )
             VALUES
                 (
                     NEW.uid,
                     NEW.uname,
     NEW.urole,
     NEW.udesig,
     NEW.usalary,
                     @group_id
                 );
         END;
     $$

DELIMITER $$
 CREATE PROCEDURE delete_revision_record()
     BEGIN
         IF @group_id IS  NULL THEN
             INSERT INTO `audit_trail_revisions`
                 (user_id, `time`)
                     VALUES
                 (@user_id, @time);
             SET @group_id = LAST_INSERT_ID();
        END IF;
     END;

 CREATE TRIGGER `test_delete` AFTER DELETE ON `test`
         FOR EACH ROW BEGIN
             CALL delete_revision_record();
             DELETE FROM `audit_trail_test` WHERE uid=_id;
        END;
     $$

query : 1.SET @user_id = ' . 42 . ', @time = NOW();
query : 2.insert into test(uname,urole,udesig,usalary) values('abc','cba','bac',10000);