SQL WHERE excluding records using AND and NOT

sqlsyntax

Here's a query I'm working on:

SELECT  TBL_SUB_KEY AS port
      , poe.[TBL_COMPANY]
      , poe.[TBL_DIVISION_1]
FROM    dbo.TMVKTAB AS poe
WHERE   ( TBL_NUMBER = '8A' )
        AND ( TBL_SUB_KEY <> '' )
        AND ( poe.[TBL_COMPANY] <> '011'
              AND poe.[TBL_DIVISION_1] <> '11'
            )

What I want returned are all the records that are not in Company = '011'/Division_1' = '11'.

I thought combining the company/division in the () would achieve this, but it does not. It eliminates all the company '011' records and it eliminates all division '11' records.

However, when I do this:

SELECT  TBL_SUB_KEY AS port
      , poe.[TBL_COMPANY]
      , poe.[TBL_DIVISION_1]
FROM    dbo.TMVKTAB AS poe
WHERE   ( TBL_NUMBER = '8A' )
        AND ( TBL_SUB_KEY <> '' )
        AND NOT ( poe.[TBL_COMPANY] = '011'
              AND poe.[TBL_DIVISION_1] = '11'
            )

it seems to pull the correct results. Why is this?

Best Solution

It's a boolean logic issue:

NOT (A and B) <=> NOT A  OR NOT B

i.e.:

NOT ( poe.[TBL_COMPANY] = '011' AND poe.[TBL_DIVISION_1] = '11')

Is equivalent to:

( poe.[TBL_COMPANY] <> '011' OR poe.[TBL_DIVISION_1] <> '11')

Read:

http://en.wikipedia.org/wiki/Boolean_logic

Related Solutions

SQL JOIN – WHERE clause vs. ON clause

They are not the same thing.

Consider these queries:

SELECT *
FROM Orders
LEFT JOIN OrderLines ON OrderLines.OrderID=Orders.ID
WHERE Orders.ID = 12345

and

SELECT *
FROM Orders
LEFT JOIN OrderLines ON OrderLines.OrderID=Orders.ID 
    AND Orders.ID = 12345

The first will return an order and its lines, if any, for order number 12345. The second will return all orders, but only order 12345 will have any lines associated with it.

With an INNER JOIN, the clauses are effectively equivalent. However, just because they are functionally the same, in that they produce the same results, does not mean the two kinds of clauses have the same semantic meaning.

Postgresql – Insert, on duplicate update in PostgreSQL

PostgreSQL since version 9.5 has UPSERT syntax, with ON CONFLICT clause. with the following syntax (similar to MySQL)

INSERT INTO the_table (id, column_1, column_2) 
VALUES (1, 'A', 'X'), (2, 'B', 'Y'), (3, 'C', 'Z')
ON CONFLICT (id) DO UPDATE 
  SET column_1 = excluded.column_1, 
      column_2 = excluded.column_2;

Searching postgresql's email group archives for "upsert" leads to finding an example of doing what you possibly want to do, in the manual:

Example 38-2. Exceptions with UPDATE/INSERT

This example uses exception handling to perform either UPDATE or INSERT, as appropriate:

CREATE TABLE db (a INT PRIMARY KEY, b TEXT);

CREATE FUNCTION merge_db(key INT, data TEXT) RETURNS VOID AS
$$
BEGIN
    LOOP
        -- first try to update the key
        -- note that "a" must be unique
        UPDATE db SET b = data WHERE a = key;
        IF found THEN
            RETURN;
        END IF;
        -- not there, so try to insert the key
        -- if someone else inserts the same key concurrently,
        -- we could get a unique-key failure
        BEGIN
            INSERT INTO db(a,b) VALUES (key, data);
            RETURN;
        EXCEPTION WHEN unique_violation THEN
            -- do nothing, and loop to try the UPDATE again
        END;
    END LOOP;
END;
$$
LANGUAGE plpgsql;

SELECT merge_db(1, 'david');
SELECT merge_db(1, 'dennis');

There's possibly an example of how to do this in bulk, using CTEs in 9.1 and above, in the hackers mailing list:

WITH foos AS (SELECT (UNNEST(%foo[])).*)
updated as (UPDATE foo SET foo.a = foos.a ... RETURNING foo.id)
INSERT INTO foo SELECT foos.* FROM foos LEFT JOIN updated USING(id)
WHERE updated.id IS NULL;

See a_horse_with_no_name's answer for a clearer example.

Best Solution

Related Solutions

SQL JOIN – WHERE clause vs. ON clause

Postgresql – Insert, on duplicate update in PostgreSQL

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