ANSI Standard

Hi,

How do I know if a function (or a certain sql syntax) in Postgres is a SQL ANSI Standard, hence it works on all databases such as MySQL, SQL Server, Oracle…

I noticed that concat, decode, nvl, instr are functions that work for some databases and don’t for others.

I only want to use ANSI Standard functions that work everywhere.

How do I identify them?

How do I know if a function is specific to Postgres and don’t work for other databases.

Sorry, I may have asked the same question more than a time

But I just wanted it to be clear

I’d appreciate any reply to my question

Thanks

Pascal