sql "for update" code example

Example 1: sql update query

--update query example
 UPDATE table_name
 SET column1 = value1, column2 = value2, ...
 WHERE condition;

Example 2: sql update

/*Swap f to m and m to f*/
UPDATE salary
SET
    sex = CASE sex
        WHEN 'm' THEN 'f'
        ELSE 'm'
    END;