Ok if I understand you, besides the language example that Dorris showed, you can write a stored procedure in another language (e.g. C# as you mentioned below) and then somehow "attach" this to the database and so when you call the function, the database is able to run the C# routine and return some value or table etc. Do I understand this correctly?

Thanks,
Albert

>>Kinda a random question but it has crossed my mind as I have worked through the many posts - what are stored procedures written in when they are contained within SQL Server or PostgreSQL server? I would assume it is some sort of function call that runs some sort of script?
>>
>>Albert
>
>Let's separate it to MS SQL Server and postgreSQL,
>
>MS SQL Server: Mostly written in T-SQL (SQL that MS SQL use). But also you could use a .Net (probably C#) language to write an SP (Stored Procedure), UDF (User Defined Function), UDT (User Defined Type), Triggers. When you do that, ie: write a UDF in C#, and register with your database, then that function become part of your database as if it were a built-in function (ie: I have some of them which one is only about parsing a comma separated value list to a single column table for passing multiple IDs as a single string. The same thing as a T-SQL procedure was timing out when thousands of IDs were passed. With the CLR version even 10+K IDs is processed in milliseconds).
>Note: SP and Function are similar with some differences. Don't overlook Functions (that returns table - aka TVF).
>
>postgreSQL: The default language is pgSQL, Comparing T-SQL and pgSQL is .... hmm no need to get blames, you can see it yourself checking a few T-SQL and pgSQL codes. Also postgreSQL supports them to be written in other languages, the ones I know off the top of my head are V8 Javascript, Python, C, Go (and I love that ability). Unlike MS SQL CLR, which is similarly supporting a .Net language is not as easy as this one.