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Set different IDs for records with conditions using a single MySQL query
For conditions, use CASE statement in MySQL. Let us first create a table −
mysql> create table DemoTable1545 -> ( -> Id int, -> FirstName varchar(20) -> ); Query OK, 0 rows affected (1.65 sec)
Insert some records in the table using insert command −
mysql> insert into DemoTable1545 values(1,'John'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable1545 values(2,'Chris'); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable1545 values(3,'Bob'); Query OK, 1 row affected (0.15 sec)
Display all records from the table using select statement −
mysql> select * from DemoTable1545;
This will produce the following output −
+------+-----------+ | Id | FirstName | +------+-----------+ | 1 | John | | 2 | Chris | | 3 | Bob | +------+-----------+ 3 rows in set (0.00 sec)
Here is the query to set different IDs using CASE statement −
mysql> update DemoTable1545 -> set Id= -> case when FirstName like '%John%' then 101 -> when FirstName like '%Chris%' then 201 -> when FirstName like '%Bob%' then 501 -> else Id -> end; Query OK, 3 rows affected (0.18 sec) Rows matched: 3 Changed: 3 Warnings: 0
Let us check the table records once again −
mysql> select * from DemoTable1545;
This will produce the following output −
+------+-----------+ | Id | FirstName | +------+-----------+ | 101 | John | | 201 | Chris | | 501 | Bob | +------+-----------+ 3 rows in set (0.00 sec)
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