Insert into partitioned table return violates check constraint but shouldn't

Question

I've a table in a postgresql and I want it to be partitioned. The structure is below

TABLE "DTD1"."logAdminActivity" ( 
    "username" CHARACTER VARYING( 200 ) NOT NULL, 
    "action" CHARACTER VARYING( 100 ) NOT NULL, 
    "pk" CHARACTER VARYING( 5 )  NOT NULL, 
    "tabel" CHARACTER VARYING( 200 )NOT NULL, 
    "timestamp" TIMESTAMP WITHOUT TIME ZONE
);

Then I've create some partition table that inherit Tabel "DTD1"."logAdminActivity" above look like this:

CREATE TABLE "DTD1".logAdminActivity_kategori ( 
    CHECK ('tabel'='kategori')
) INHERITS ("DTD1"."logAdminActivity");

CREATE TABLE "DTD1".logAdminActivity_subyek (
    CHECK ('tabel'='subyek')
 ) INHERITS ("DTD1"."logAdminActivity");

...

CREATE TABLE "DTD1".logAdminActivity_satuan (
    CHECK ('tabel'='satuan')
 ) INHERITS ("DTD1"."logAdminActivity");

CREATE TABLE "DTD1".logAdminActivity_memberfilter (
    CHECK ('tabel'='memberFilter')
 ) INHERITS ("DTD1"."logAdminActivity");

After that I create indexes each partitioned table in username coloumn. Then I create this trigger function and trigger that call that trigger function in below. So, when I insert the data, the coresponding tabel coloumn will be redirected into proper partition table.

CREATE OR REPLACE FUNCTION "DTD1".logAdminActivity_insert_trigger()
RETURNS TRIGGER AS $$
BEGIN
    IF ( New."tabel" = 'kategori' ) THEN
        INSERT INTO "DTD1".logAdminActivity_kategori VALUES (NEW.*);
    ELSIF ( New."tabel" = 'subyek' ) THEN
        INSERT INTO "DTD1".logAdminActivity_subyek VALUES (NEW.*);
    ..    
    ELSE
        RAISE EXCEPTION 'Tabel out of range.  Fix the logAdminActivity_insert_trigger() function!' ;
    END IF;
    RETURN NULL;
END;
$$
LANGUAGE plpgsql;

CREATE TRIGGER insert_logAdminActivity_trigger
    BEFORE INSERT ON "DTD1"."logAdminActivity"
    FOR EACH ROW EXECUTE PROCEDURE "DTD1".logAdminActivity_insert_trigger();

Then I test it by insert procedure such as

INSERT INTO "DTD1"."logadminactivity_subyek" ( "action", "pk", "tabel", "timestamp", "username") 
VALUES ( 'bla', '12312', 'subyek', '2014-01-01 02:02:03', 'asdf' );

But why it return error look like this

ERROR: new row for relation "logadminactivity_subyek" violates check constraint "logadminactivity_subyek_check" DETAIL: Failing row contains (asdf, bla, subyek, 12312, 2014-01-01 02:02:03).

How it can be happened because I've try to follow the documentation in this ?

http://www.postgresql.org/docs/9.3/static/ddl-partitioning.html

I think the 'tabel' value from query above ('subyek') is not match with trigger function but when I check with check constrain it pass. Is there any part I miss about it or is there any solution to solve this problem?

Regards

Answer 1

CHECK ('tabel'='subyek')

That check constraint is incorrect because 'tabel' is a constant.

It is equivalent to CHECK (false).

You want

CHECK ("tabel"='subyek')