How to update a MySQL column by subtracting a value with some conditions?

Let us first create a table −

mysql> create table DemoTable
(
   Score int
);
Query OK, 0 rows affected (0.65 sec)

Insert some records in the table using insert command −

mysql> insert into DemoTable values(45);
Query OK, 1 row affected (0.11 sec)
mysql> insert into DemoTable values(29);
Query OK, 1 row affected (0.11 sec)
mysql> insert into DemoTable values(56);
Query OK, 1 row affected (0.09 sec)
mysql> insert into DemoTable values(24);
Query OK, 1 row affected (0.09 sec)
mysql> insert into DemoTable values(32);
Query OK, 1 row affected (0.09 sec)

Display all records from the table using select statement −

mysql> select *from DemoTable;

This will produce the following output −

+-------+
| Score |
+-------+
|    45 |
|    29 |
|    56 |
|    24 |
|    32 |
+-------+
5 rows in set (0.00 sec)

Following is the query to update MySQL column by subtracting a value with some conditions −

mysql> update DemoTable set Score=Score-2 where Score > 30;
Query OK, 3 rows affected (0.14 sec)
Rows matched: 3 Changed: 3 Warnings: 0

Let us check the table records once again −

mysql> select *from DemoTable;

This will produce the following output −

+-------+
| Score |
+-------+
|    43 |
|    29 |
|    54 |
|    24 |
|    30 |
+-------+
5 rows in set (0.00 sec)

AmitDiwan

Published on 24-Sep-2019 12:47:10

• Related Questions & Answers
• Subtracting a number from a single MySQL column value?
• How to update MySQL column with random value?
• How to change a column in an R data frame with some conditions?
• Update only a single column value in MySQL
• How to update a MySQL table by swapping two column values?
• Update a MySQL column with JSON format?
• How to update a specific column value fetched with CASE statement?
• Subtracting a day in MySQL
• How to update a MySQL date type column?
• Update a column value, replacing part of a string in MySQL?
• Update a column of text with MySQL REPLACE()
• SELECT a row by subtracting dates in WHERE in MySQL?
• How to update records in a column with random numbers in MySQL?
• How to update a value with substring of current value by removing the separator and numbers after a separator in MySQL?
• MySQL SELECT to sum a column value with previous value