How to increase a value in a table by a certain number without reading last value and afterwards updating it?
product | quantity |
---|---|
iLamp | 50 |
I want to increase (or decrease) quantity by x. I am first reading last value (50), increasing or decreasing it, and writing it back. Is there a direct way?
ベストアンサー1
Example 1 (for all rows):
UPDATE product SET price = price + 50
Example 2 (for a specific row):
UPDATE product SET price = price + 50 WHERE id = 1
Example 3 (for specific rows):
UPDATE product SET price = price + 50 WHERE id IN [1, 2, 3]
Example 4 (generic):
UPDATE {table} SET {column} = {column} + {value} WHERE {condition}
Where:
{table}
- table name{column}
- column name{value}
- a number by which column's value should be increased or decreased{condition}
- some condition if any