Drop column constraint

On 10/30/20 8:30 AM, Rich Shepard wrote:

A table has a unique constraint on a column that needs removing. Reading
the
postgres-12.x docs for alter table it appears the correct syntax is:

alter table locations drop constraint unique;

It should be:

alter table locations drop constraint 'constraint_name';

Where you can find 'constraint_name' from:

\d locations

but this is wrong.

Trying 'alter table locations alter column loc_nbr drop constraint
unique;' also
failed.

What's the proper syntax to drop the unique constraint on a table column?

TIA,

Rich

--
Adrian Klaver
adrian.klaver@aklaver.com

On 30/10/2020 15:30, Rich Shepard wrote:

A table has a unique constraint on a column that needs removing.
Reading the
postgres-12.x docs for alter table it appears the correct syntax is:

alter table locations drop constraint unique;

but this is wrong.

Trying 'alter table locations alter column loc_nbr drop constraint
unique;' also
failed.

What's the proper syntax to drop the unique constraint on a table column?

TIA,

Rich

You need

alter table locations drop constraint <constraint name>;

Cheers, Chris Sterritt

On Fri, 30 Oct 2020, Adrian Klaver wrote:

It should be:
alter table locations drop constraint 'constraint_name';

Adrian,

Yes, I forgot to quote the constraint_name, And, I used the DDL name
'unique' rather than the internal name "locations_loc_nbr_key". Using the
latter, and adding 'cascade' (because the dependent table is empty) did the
trick.

Thank you,

Rich

On 10/30/20 8:54 AM, Rich Shepard wrote:

On Fri, 30 Oct 2020, Adrian Klaver wrote:

It should be:
alter table locations drop constraint 'constraint_name';

Adrian,

Yes, I forgot to quote the constraint_name, And, I used the DDL name
'unique' rather than the internal name "locations_loc_nbr_key". Using the

Actually unique is not the name, it is the constraint type. You can
create your own name when creating the constraint or Postgres will
create one for you.

latter, and adding 'cascade' (because the dependent table is empty) did the
trick.

Thank you,

Rich

--
Adrian Klaver
adrian.klaver@aklaver.com

On Fri, 30 Oct 2020, Adrian Klaver wrote:

Actually unique is not the name, it is the constraint type. You can create
your own name when creating the constraint or Postgres will create one for
you.

Adrian,

Got it, thanks.

Rich