Re: A new scenario for check constraints

On Fri, Oct 8, 2021 at 4:14 AM Shaozhong SHI <shishaozhong(at)gmail(dot)com> wrote:

> Hi, All,
>
> Can Postgres do some thing like this one?
> Checking for potential constraint violations before entering SQL Server
> TRY and CATCH logic (mssqltips.com)
> <https://www.mssqltips.com/sqlservertip/2632/checking-for-potential-constraint-violations-before-entering-sql-server-try-and-catch-logic/>
>
> The scenario is that we have a large Postgres table. Can a solution be
> designed to create a table with constraint specifications and filter in all
> records meeting specifications and producing reports (e.g., on problematic
> ones)?
>
> Your question about TRY/CATCH and your subsequent paragraph don't seem
related to me. For exception handling, I think functionally it's identical
to the MS SQL example you shared (though syntactically different):
https://www.postgresql.org/docs/current/plpgsql-control-structures.html#PLPGSQL-ERROR-TRAPPING

Regarding your second question, I think you just want to write some stored
procedures -- the cool thing about Pg is you can write them in almost any
language you can think of, but I believe writing them in SQL is the easiest
and with the most support/examples online:

You can create "procedures" and "functions" and to be honest I'm not
totally clear on the difference, but I know others here are:
https://www.postgresql.org/docs/current/sql-createprocedure.html

Write with specific issues you are having and the specific code you are
using, and the results you are expecting and you'll get better support.

Steve