How to get the name of a unique constraint in postgresql?

Question

I need to drop a unique constraint from a postgresql table, but I didn't give it a name in the schema. Does anybody know, how to get the name of such a constraint, or how to drop it?

Answer 1

That is something like (for single column constaint):

tableName_columnName_key 

To get constaint name write (in psql):

\d tableName 

or use pg_constraint system catalog:

SELECT conname FROM pg_constraint WHERE conrelid =     (SELECT oid      FROM pg_class     WHERE relname LIKE 'tableName'); 

Also you can get it from pgAdmin in objects tree.