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)

AmitDiwan

Published on 12-Dec-2019 06:08:53

• Related Questions & Answers
• Multiple COUNT() for multiple conditions in a single MySQL query?
• MySQL query to concatenate records with similar corresponding ids in a single row separated by a special character
• Display records with conditions set using if statement in UPDATE statement with MySQL
• MySQL update multiple records in a single query?
• Delete records from a MySQL table with IN() in a single query
• MySQL Query to set currency records
• MySQL query to set different combinations for values in a table?
• Counting different distinct items in a single MySQL query?
• How to set different auto-increment ids for two tables with a user-defined variable?
• Select count of values (Yes, No) with same ids but different corresponding records in MySQL?
• MySQL query with OR & AND conditions
• Using MySQL keywords in a query surrounded with single quotes?
• Count two different columns in a single query in MySQL?
• Set conditions for columns with values 0 or 1 in MySQL
• Order MySQL query by multiple ids?