https://stackoverflow.com › questions › 43934155

The short answer is that COALESCE function is what you can use in postgres. COALESCE is better than IFNULL for several reasons: COALESCE is a standard SQL function (implemented in ~every RDBMS), while IFNULL is not standard, even if widely used.

https://stackoverflow.com › questions › 2214525

IsNull forces the result-type to the type of argument1, while coalesce uses the respective types for each argument. If you just search-and-replace isnull with coalesce, you can potentially get a lot of errors...

https://www.postgresql.org › docs › current › functions-conditional.html

NULLIF returns a null value if its two arguments are equal, otherwise it returns the first argument. Learn how to use NULLIF and other conditional expressions in PostgreSQL, such as CASE, COALESCE, GREATEST and LEAST.

https://stackoverflow.com › questions › 49042477

NULLIF() is very different from IFNULL(). I think that what you want is COALESCE(), which will return the first non-NULL argument (it can have more than 2 arguments): SELECT * FROM table_a WHERE NOT (COALESCE(column_a::boolean, false)); Reference: 9.17.2. COALESCE. Also, in Postgres you need to use true or false. 0 and 1 do not work for boolean ...

https://docs.postgresql.fr › 15 › functions-conditional.html

Cette fonction du standard SQL fournit des possibilités similaires à NVL et IFNULL, qui sont utilisées dans d'autres systèmes de bases de données.

https://www.postgresqltutorial.com › postgresql-tutorial › postgresql-nullif

Learn how to use the NULLIF function to handle null values in PostgreSQL. See examples of basic usage, table data, and division-by-zero prevention with NULLIF.

https://www.postgresqltutorial.com › postgresql-tutorial › postgresql-coalesce

In this tutorial, you will learn about the PostgreSQL COALESCE() function that returns the first non-null argument.

https://docs.postgresql.fr › 9.6 › functions-conditional.html

Cette section décrit les expressions conditionnelles respectueuses du standard SQL disponibles avec PostgreSQL ™.