CODEWITHSUNDEEP
postgresql
Standaa - Remember Monica
Standaa - Remember Monica

Reputation: 1920

Postgres : Difference between timestamp 'myTimestamp' and 'myTimestamp'::timestamp

I stumbled upon this S.O question, which mentions that a check constraint has to be written like this: CHECK (ts >= timestamp '2015-08-11 00:00:00' AND ts < timestamp '2015-08-12 00:00:00')

I am personally writing my type casts like this : CHECK (ts >= '2015-08-11 00:00:00'::timestamp AND ts < '2015-08-12 00:00:00'::timestamp)

Is 'timestamp' a type cast in the first example ? Are both checks equivalent ? Is there any performance difference between the two ?

Upvotes: 0

Views: 39

Answers (1)

user330315
user330315

Reputation:

The first syntax: '2015-08-11 18:30:00' is standard ANSI SQL to write a timestamp literal, this is also used for dates: date '2015-08-11' or just a time value: time '18:30:00'. This is a "constant" value, not a "cast" similar to simply writing 'foobar' as a varchar constant.

The second form is a cast from a text value to a timestamp and is Postgres specific.

Upvotes: 1

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