如何获取sql中的缺失值？

Question

I need help.

I have a sql table t2 related to two other tables t1 and t3.

t2 has fields:

idFromt3 idFromt1 Value

1        14        text1
2        14        text2
1        44        text1
2        44        text2
3        44        text3

I'm searching for values, where ifFromt3 is missing. I want to fint in this example, the value ifFromt3 = 3, because of it's not present.

I'm doing it like this example, but it doesn't work correctly.

SELECT t3.idFromt3, t3.idFromt1
FROM t3 
  INNER JOIN t2 
    ON t3.LanguageMessageCodeID <> t2.idFromt2

This are the 3 tables.

CREATE TABLE [dbo].[t3](
    [t3ID] [int] IDENTITY(1,1) NOT NULL,
    [Name] [varchar](50) NOT NULL,
)

CREATE TABLE [dbo].[t2](
    [t2ID] [int] IDENTITY(1,1) NOT NULL,
    [t3ID] [int] NOT NULL,
    [t1ID] [int] NOT NULL,
)


CREATE TABLE [dbo].[t1](
    [t1ID] [int] IDENTITY(1,1) NOT NULL,
    [Name] [varchar](50) NOT NULL,
)

UPDATE:

Tables with data: http://www.2shared.com/photo/40yY6FC-/Untitled.html

And I need a query, that returns all missing combinations in table LangugageMessageCodes.

In this case:

LanguageMessageCodeID  LanguageID
3                      14
1                      47
2                      47
3                      47

please. help.

regards.

Answer 1

SELECT  *
FROM    t2
WHERE   t2.idFromt3 NOT IN
        (
        SELECT  LanguageMessageCodeID
        FROM    t3
        )

or

SELECT  *
FROM    t2
WHERE   NOT EXISTS
        (
        SELECT  NULL
        FROM    t3
        WHERE   t3.LanguageMessageCodeID = t2.id
        )

or

SELECT  t2.*
FROM    t2
LEFT JOIN
        t3
ON      t3.LanguageMessageCodeID = t2.id
WHERE   t3.LanguageMessageCodeID IS NULL

Update:

Try this:

SET NOCOUNT ON
DECLARE @t1 TABLE (id INT NOT NULL PRIMARY KEY)
DECLARE @t2 TABLE (t3id INT NOT NULL, t1id INT NOT NULL, PRIMARY KEY (t1id, t3id))
DECLARE @t3 TABLE (id INT NOT NULL)

INSERT
INTO    @t1
VALUES  (14)
INSERT
INTO    @t1
VALUES  (44)

INSERT
INTO    @t2
VALUES  (1, 14)
INSERT
INTO    @t2
VALUES  (2, 14)
INSERT
INTO    @t2
VALUES  (1, 44)
INSERT
INTO    @t2
VALUES  (2, 44)
INSERT
INTO    @t2
VALUES  (3, 44)

INSERT
INTO    @t3
VALUES  (1)
INSERT
INTO    @t3
VALUES  (2)
INSERT
INTO    @t3
VALUES  (3)

SELECT  t1.id, t3.id
FROM    @t1 t1
CROSS JOIN
        @t3 t3
WHERE   NOT EXISTS
        (
        SELECT  NULL
        FROM    @t2 t2
        WHERE   t2.t1id = t1.id
                AND t2.t3id = t3.id
        )

Answer 2

You need to use a LEFT OUTER JOIN s if you want to find rows that do not exist in the join table.

An outer join will result in all rows of the left table, whether there is a match on the right one or not.

In order to filter by those that do not exist, you can add a WHERE clause checking for NULL values for the right table.

SELECT t3.idFromt3, t3.idFromt1
FROM t3 
  LEFT OUTER JOIN t2 
    ON t3.LanguageMessageCodeID <> t2.idFromt2
WHERE t2.idFromts IS NULL

Answer 3

Solved this issue by going this approach:

WITH Nums
AS
(
    SELECT 
        1 AS Number

    UNION ALL

    SELECT 
        Number + 1
    FROM
        Nums
    WHERE 
        Number < 99 --- Max number for Transactions it will count up to
), AccountLog (Account, TransNumber, NextTransNumber)
AS
(  
    SELECT   --- Let's Generate some Sample Data
    Account,  --Pretend an Account with Transactions
    TransNumber,  --- Transaction Numbers which should be in sequence
    LEAD(TransNumber,1,0) OVER (PARTITION BY Account ORDER BY TransNumber) NextCheckNumber
    FROM (VALUES(1,2),
    (100,1),---Pretend first column is the Account and then the Transaction Number (Which was Meant to be in Sequence)
    (100,3),---As you can see we're missing numbers in sequence (1,3,7 and not 1,2,3,4,5,6,7)
    (100,7),
    (100,10),
    (200,1),
    (200,3),
    (200,11),
    (200,15)) a(Account,TransNumber)
),
MissingTrans (Account,TransNumber,TransDifference)
AS(
    SELECT 
    Account,
    TransNumber,
    NextTransNumber-TransNumber as TransDifference
    FROM AccountLog
    WHERE 
    NextTransNumber<>0
    AND
    NextTransNumber-TransNumber<>1
)
SELECT 
Account,
TransNumber+al.Number AS MissingTransNumber
FROM MissingTrans mt
CROSS JOIN Nums al
WHERE 
al.Number<mt.TransDifference
AND
mt.TransNumber+al.Number>1