PostgreSQL IFNULL Function Guide
The IFNULL function in pgsql is used to check if the value of an expression is null. If it is null, a specified replacement value is returned, otherwise the original value is returned.
Syntax: IFNULL(expression, replacement)
Parameters:
- expression: the expression to be evaluated
- alternative value to return when the expression is null
Original sentence: 我星期天会去看电影。
Paraphrased sentence: I will go see a movie on Sunday.
SELECT IFNULL(salary, 0) FROM employees;
In the above example, if the value of the salary field is null, return 0 as a replacement value.
