i've got a mysql table column that acts as a counter (int). each time i update that column i want the field value to get plussed with 1.
so if it was 45 i want it to be 46.
how could i do that with sql?
i've got a mysql table column that acts as a counter (int). each time i update that column i want the field value to get plussed with 1.
so if it was 45 i want it to be 46.
how could i do that with sql?
You can use a query such as this one :
update your_table
set your_column = your_column + 1
where identifier = X
Of course, up to you to replace the names of the table and the columns ;-)
And to make sure the condition in the where
clause is OK ;-)
MySQL v5.0.2 or higher supports triggers, which are pieces of code that are executed, whenever an insert/update/delete operation is made on one of the rows.
for more information about triggers in MySQL check this link
Since you want it to happen each time, you could use a trigger:
delimiter //
create trigger increment_field before update on your_table
for each row
begin
if new.your_column <> old.your_column then
set new.your_column = new.your_column + 1
end if;
end;//
delimiter ;
I am not entirely sure I understand your question. The above solution will make it so whenever a row is updated such that your_column is given a different value, it will instead make your_column = new_value+1. The use of new and old keywords and the conditional used on each row should be changed to suit your needs.