[postgis-users] Help with a selection query

[paul.malm at lfv.se]

I’ve sent this question to postgres user group without any success. Thats why I’m trying with you.

I have a column named col (varchar)
 
col could look like this
902930
902920
902900
903110
913210
913200
…
I would like to remove an object that doesn’t end ‘00’ and if there are objects that start with the same 4 charcters and ending with 00.
All objects ending with 00 shall remain.
All objects not ending with 00 shall remain if there is no object starting with the same 4 characters and ending with 00   
 
The result of the col table should be:
902900
903110
913200
 
903110 is not removed because there is no 903100
913210 is removed because there is a 913200
902930 and 902920 are removed because there is 902900
 
I hope you understand the logic , perhaps there is no logic in my explanation.
Thanks in advance,
Paul