如何獲取sql中的缺失值？

Question

我需要幫助。

我有一個與另外兩個表 t1 和 t3 相關的 sql 表 t2。

t2 有字段：

idFromt3 idFromt1 Value

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

我正在尋找缺少 ifFromt3 的值。 我想在這個例子中找到值 ifFromt3 = 3，因為它不存在。

我正在像這個例子那樣做，但它不能正常工作。

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

這是3張桌子。

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,
)

更新：

數據表： http : //www.2shared.com/photo/40yY6FC-/Untitled.html

我需要一個查詢，它返回表LangugageMes​​sageCodes 中所有缺失的組合。

在這種情況下：

LanguageMessageCodeID  LanguageID
3                      14
1                      47
2                      47
3                      47

請。 幫助。

問候。

Answer 1

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

或

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

或

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

更新：

試試這個：

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

如果要查找連接表中不存在的行，則需要使用LEFT OUTER JOIN 。

外連接將導致左表的所有行，無論右表是否存在匹配項。

為了過濾不存在​​的那些，您可以添加一個WHERE子句檢查右表的NULL值。

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

Answer 3

通過采用這種方法解決了這個問題：

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