Question

DELIMITER $$
CREATE TRIGGER `tr_tblEmployee_Update` BEFORE UPDATE ON `tblEmployee` FOR EACH ROW 
BEGIN

 DECLARE id int; DECLARE OldGender varchar(10); DECLARE NewGender varchar(10); DECLARE NewName varchar(50); DECLARE OldName varchar(50);
 DECLARE OldSalary int; DECLARE NewSalary int; DECLARE OldID_Dep int; DECLARE NewId_Dep int;
 DECLARE AuditString varchar(300);

    SET id = ID_Employee; SET NewGender = Gender; SET NewName = Name; SET NewSalary = Salary; SET NewID_Dep = ID_Dep;
    SET OldGender = Gender; SET OldName = Name; SET OldSalary = Salary; SET OldID_Dep = ID_Dep;

    SET AuditString = concat('Employee with id = ',id,' changed: ')
    IF(OldName<>NewName)
        SET AuditString = concat(AuditString, 'Name from ',OldName,' to ',NewName);
    IF(OldGender<>NewGender)
        SET AuditString = concat(AuditString, ' Gender from ',OldGender,' to ',NewGender);
    IF(OldSalary<>NewSalary)
        SET AuditString = concat(AuditString, ' Salary from ',OldName,' to ',NewName);
    IF(OldDep<>NewDep)
        SET AuditString = concat(AuditString, ' Department from ',OldName,' to ',NewName);

    INSERT INTO tblemployeeaudit(AuditData) VALUES(AuditString);
END
$$
DELIMITER ;

您好，我想多次使用具有相同变量（AuditString）的concat函数，但每次尝试执行此操作时都会出错。

错误 - ＃1064 - 您的SQL语法出错;检查手册对应于您的MariaDB服务器版本以获得正确的语法在'IF（OldName！= NewName）附近使用 SET AuditString = concat（AuditString，'Name from'，Ol'... at line 12

Answer 1

这是最终解决方案，以防其他人遇到与我相同的问题。

DELIMITER $$ 在tr_tblEmployee_Update之前为每个行创建TRIGGER tblEmployee BEGIN

DECLARE id int; DECLARE OldGender varchar（10）; DECLARE NewGender varchar（10）; DECLARE NewName varchar（50）; DECLARE OldName varchar（50）; DECLARE OldSalary int; DECLARE NewSalary int; DECLARE OldID_Dep int; DECLARE NewId_Dep int; DECLARE AuditString varchar（300）;

SET id = OLD.ID_Employee; SET NewGender = NEW.Gender; SET NewName = NEW.NAME; SET NewSalary = NEW.Salary;
SET OldGender = OLD.Gender; SET OldName = OLD.NAME; SET OldSalary = OLD.Salary;

SET AuditString = concat('Employee with id = ',id,' changed: ');
IF(OldName<>NewName) THEN
    SET AuditString = concat(AuditString, 'Name from ',OldName,' to ',NewName);
END IF;
IF(OldGender<>NewGender) THEN
    SET AuditString = concat(AuditString, ' Gender from ',OldGender,' to ',NewGender);
END IF;
IF(OldSalary<>NewSalary) THEN
    SET AuditString = concat(AuditString, ' Salary from ',OldSalary,' to ',NewSalary);
END IF;    
INSERT INTO tblemployeeaudit(AuditData) VALUES(AuditString);

END

如何在函数concat（）MySql中多次使用相同的变量

1 个答案: