如何将变量传递给 MySQL 脚本?
mysqlmysqli database
您可以使用会话变量将变量传递给 MySQL 脚本。首先，您需要使用 SET 命令设置会话变量。之后，您需要将该变量传递给 MySQL 脚本。
语法如下 −
第一步:使用 Set 命令。
SET @anyVariableName − = ’yourValue’;
第二步:将变量传递给 MySQL 脚本。
UPDATE yourTableName SET yourColumnName1 = yourColumnName1+integerValue WHERE yourColumnName2 = @anyVariableName;
为了理解上述语法，让我们创建一个表。创建表的查询如下 −
mysql> create table Employee_Information -> ( -> EmployeeId int NOT NULL AUTO_INCREMENT, -> EmployeeName varchar(20) NOT NULL, -> EmployeeSalary int, -> EmployeeStatus varchar(20), -> PRIMARY KEY(EmployeeId) -> ); Query OK, 0 rows affected (0.53 sec)
现在，您可以使用 insert 命令在表中插入一些记录。查询如下 −
mysql> insert into Employee_Information(EmployeeName,EmployeeSalary,EmployeeStatus) values('Sam',17650,'FullTime');
Query OK, 1 row affected (0.13 sec)
mysql> insert into Employee_Information(EmployeeName,EmployeeSalary,EmployeeStatus) values('Carol',12000,'Trainee');
Query OK, 1 row affected (0.18 sec)
mysql> insert into Employee_Information(EmployeeName,EmployeeSalary,EmployeeStatus) values('Bob',17650,'FullTime');
Query OK, 1 row affected (0.20 sec)
mysql> insert into Employee_Information(EmployeeName,EmployeeSalary,EmployeeStatus) values('Mike',12000,'Trainee');
Query OK, 1 row affected (0.14 sec)
mysql> insert into Employee_Information(EmployeeName,EmployeeSalary,EmployeeStatus) values('John',17650,'FullTime');
Query OK, 1 row affected (0.16 sec)
使用 select 语句显示表中的所有记录。
mysql> select *from Employee_Information;
以下是输出 −
+------------+--------------+----------------+----------------+ | EmployeeId | EmployeeName | EmployeeSalary | EmployeeStatus | +------------+--------------+----------------+----------------+ | 1 | Sam | 17650 | FullTime | | 2 | Carol | 12000 | Trainee | | 3 | Bob | 17650 | FullTime | | 4 | Mike | 12000 | Trainee | | 5 | John | 17650 | FullTime | +------------+--------------+----------------+----------------+ 5 rows in set (0.00 sec)
以下是将变量传递给 MySQL 脚本 − 的查询
mysql> set @EmpStatus − = 'FullTime'; Query OK, 0 rows affected (0.03 sec) mysql> update Employee_Information set EmployeeSalary = EmployeeSalary+6500 where EmployeeStatus = @EmpStatus; Query OK, 3 rows affected (0.18 sec) Rows matched − 3 Changed − 3 Warnings − 0
现在再次使用 SELECT 语句检查表记录。我已将 EmployeeSalary 增加了 6500，适用于全职工作的员工。
查询如下 −
mysql> select *from Employee_Information;
以下是输出 −
+------------+--------------+----------------+----------------+ | EmployeeId | EmployeeName | EmployeeSalary | EmployeeStatus | +------------+--------------+----------------+----------------+ | 1 | Sam | 24150 | FullTime | | 2 | Carol | 12000 | Trainee | | 3 | Bob | 24150 | FullTime | | 4 | Mike | 12000 | Trainee | | 5 | John | 24150 | FullTime | +------------+--------------+----------------+----------------+ 5 rows in set (0.00 sec)
