Mysql query: decrease value by 1
mysql
Solution
You don't need any quotes.
UPDATE my_table SET my_field = my_field - 1 WHERE `other` = '123'
To understand, it's like a classic affectation in any languages: "I want `my_field` being equal to `my_field` (the current value) minus `1`. If you put quotes, it means "I want `my_field` being equal to the string:
- `'my_field-1'` (for your first query)
- `'my_field' - 1` (which means nothing, at least for me: what the result of a string minus an integer?)
- `'-1'`, which will be converted to -1 if your field has the INTEGER signed type.
In some cases (if you have spaces or special characters if your field name), you can surrounded the field name with `backticks`:
UPDATE my_table SET `my_field` = `my_field` - 1 WHERE other = '123'
Problem
I would like decrease by 1 the value contained inside a field (integer or drop-down). I tried these 3 queries but none of them work as expected: ``` UPDATE `my_table` SET `my_field` = 'my_field-1' WHERE `other` = '123' UPDATE `my_table` SET `my_field` = 'my_field' -1 WHERE `other` = '123' UPDATE `my_table` SET `my_field` = '-1' WHERE `other` = '123' ``` I searched here and on Google but all solutions I found are similar. Any idea why this doesn't work at my side?