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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)
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