While working on a proxy checker tool for one of my projects, I was struggling on how to execute a conditional query on my SQLite database to update a column only if its value is greater than 0 (it would be pointless in my case to let the script update the column with negative values).

In Mysql one would do like this (we use the ternary operator IF(to_check_expression>0,expression1,expression2)):

update table_name set column_name=IF((column_name-1)>0,(column_name-1),0)

However, in SQLite this method will not work. Instead I had to use the case when (condition) then expression1 else expression2 end method.

The above query in MySQL can be rewritten like this in SQLite:

update table_name set column_name=case when (column_name-1)>0 then (column_name-1) else 0 end

That’s it. I hope it helps someone!

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