The relation was created in Postgres 9.6 with use of the following commands:
CREATE TABLE import_event ( import_event_id BIGINT NOT NULL, filename VARCHAR (200) CONSTRAINT NN_import_event__filename NOT NULL ); ALTER TABLE ONLY import_event ADD CONSTRAINT PK_import_cak_key PRIMARY KEY (import_event_id);
Notice that not null constraint is named.
Then the following command was executed
insert into import_event (import_event_id) values (1);
Of course, the constraint violation error was raised. The content of the message is as follows
ERROR: null value in column "filename" violates not-null constraint DETAIL: Failing row contains (1, null).**strong text**
The problem is that the name of not null constraint is missing in that message. However, the correct error message:
ERROR: new row for relation "import_event" violates check constraint "nn_import_event__filename"
is produced when not null constraint is declared as follows
ALTER TABLE ONLY import_event ADD CONSTRAINT NN_import_event__filename CHECK(filename IS NOT NULL);
Is that a bug in Postgres 9.6 or is there a problem with constraint declaration?