How do I use the @ sign in MySQL?
To use the @ sign, use MySQL SET command. The @sign is used to set user-defined variables. Following is the syntax −
SET @anyVariableName:=yourValue;
Let us first create a table −
mysql> create table DemoTable1331
-> (
-> Id int,
-> Name varchar(20)
-> );
Query OK, 0 rows affected (0.51 sec)
Insert some records in the table using insert command −
mysql> insert into DemoTable1331 values(10,'Chris');
Query OK, 1 row affected (0.71 sec)
mysql> insert into DemoTable1331 values(101,'David');
Query OK, 1 row affected (0.13 sec)
mysql> insert into DemoTable1331 values(40,'Bob');
Query OK, 1 row affected (0.12 sec)
mysql> insert into DemoTable1331 values(30,'Mike');
Query OK, 1 row affected (0.15 sec)
mysql> insert into DemoTable1331 values(60,'John');
Query OK, 1 row affected (0.12 sec)
Display all records from the table using select statement −
mysql> select * from DemoTable1331;
This will produce the following output −
+------+-------+
| Id | Name |
+------+-------+
| 10 | Chris |
| 101 | David |
| 40 | Bob |
| 30 | Mike |
| 60 | John |
+------+-------+
5 rows in set (0.00 sec)
Here is the query to use @sign in MySQL −
mysql> set @Value:=40;
Query OK, 0 rows affected (0.00 sec)
mysql> select * from DemoTable1331 where Id > @Value;
This will produce the following output −
+------+-------+
| Id | Name |
+------+-------+
| 101 | David |
| 60 | John |
+------+-------+
2 rows in set (0.03 sec)
Published on 05-Nov-2019 11:21:43
