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)
Published on 12-Dec-2019 10:38:53
