You can pass a variable to a MySQL script using session variable. First you need to set a session variable using SET command. After that you need to pass that variable to a MySQL script.
The syntax is as follows −
First Step: Use of Set command.
SET @anyVariableName − = ’yourValue’;
Second Step: Pass a variable to a MySQL script.
UPDATE yourTableName SET yourColumnName1 = yourColumnName1+integerValue WHERE yourColumnName2 = @anyVariableName;
To understand the above syntax, let us create a table. The query to create a table is as follows −
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)
Now you can insert some records in the table using insert command. The query is as follows −
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)Display all records from the table using select statement.
mysql> select *from Employee_Information;
The following is the output −
+------------+--------------+----------------+----------------+ | 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)
The following is the query to pass a variable to a MySQL script −
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
Now check the table records once again using SELECT statement. I have incremented the EmployeeSalary with 6500, for the employees working FullTime.
The query is as follows −
mysql> select *from Employee_Information;
The following is the output −
+------------+--------------+----------------+----------------+ | 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)