how can I query for unset timestamps - Mailing list pgsql-sql

From Bret Hughes
Subject how can I query for unset timestamps
Date
Msg-id 1109106594.3945.120.camel@bretsony
Whole thread Raw
List pgsql-sql
I have a table that I recently altered by adding several timestamp
columns.  I would like to query the table for those rows for which the
timestamp has not been set but am unable to find a way to do so.  any
tips ?  in psql the column appears empty and char_length returns
nothing.

Some of what I have tried 

"" -> not valid

char_length(last_timestamp) > 0  -> returns the rows with the time
stamps

where NOT char_length(last_timestamp) > 0  -> returns 0 rows

where NOT (char_length(last_timestamp) > 0 ) -> returns 0 rows

where last_timestamp = NULL;  -> 0 rows

this is kicking my butt, and starting to piss me off so if any one has
tips I would appreciate it.

Bret





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