RE: Order of operations in postgreSQL. - Mailing list pgsql-bugs

From Wetmore, Matthew (CTR)
Subject RE: Order of operations in postgreSQL.
Date
Msg-id 668989cd22e8457ca7a85d0e74c34bde@express-scripts.com
Whole thread Raw
In response to Order of operations in postgreSQL.  ("Ken McClaren" <ken.mcclaren@kipuhealth.com>)
Responses Re: Order of operations in postgreSQL.  ("Ken McClaren" <ken.mcclaren@kipuhealth.com>)
List pgsql-bugs

From your stackoverflow example. (please don’t post links, they will be hard to use in future if link expires)

 

This is what is happening.

 

Your code:  TO_TIMESTAMP( trim ( substring(m.text_value, 1, 19)), 'YYYY-MM-DD"T"HH24:MI:SS' ) as tms 
 

Your ERROR: ERROR: invalid value "test" for "YYYY"

 

Postgres logs are very clear about what is going on, if you step back and read them.

 

Test is in ‘’, the error says ‘test’ is invalid for YYYY

 

Reproduced by:

 

SELECT TO_TIMESTAMP( trim ( substring('test00000000000000', 1, 19)), 'YYYY-MM-DD"T"HH24:MI:SS' )

 

Returns: ERROR: invalid value "test" for "YYYY" DETAIL: Value must be an integer.

 

From: Ken McClaren <ken.mcclaren@kipuhealth.com>
Sent: Wednesday, May 31, 2023 10:49 AM
To: pgsql-bugs@lists.postgresql.org
Cc: John Hall <john.hall@kipuhealth.com>
Subject: [EXTERNAL] Order of operations in postgreSQL.

 

https://stackoverflow.com/questions/76339408/gracefully-handle-datatime-in-postgresql/76345292?noredirect=1#comment134659364_76345292

 

Just a few notes on this issue:

 

PSQL:

Appears to be applying the filter to all the columns in the table after the join.

 

TSQL:

Tried to duplicate this behavior and got these results.

 

select t1.id as t1id,

       cast(cast(t1.test_value as varchar(max)) as datetime) as tms

from table1 t1

    join table2 t2

        on t1.id = t2.id

where cast(cast(t1.test_value as varchar(max)) as datetime) > '2023-05-27'

 

These statements work as expected in SQL Server.

 

Let me know if you have any questions.

 

 

 

Logo

Description automatically generated

Ken McClaren
Database Administrator

 

864.313.5997

Easley, SC

Instagram | LinkedIn | Facebook | Twitter

kipuhealth.com 

 

 

 

Attachment

pgsql-bugs by date:

Previous
From: "Ken McClaren"
Date:
Subject: Order of operations in postgreSQL.
Next
From: Kyotaro Horiguchi
Date:
Subject: Re: BUG #17947: Combination of replslots pgstat issues causes error/assertion failure