Искомое предложение по запросу

Question

мы можем получить как «новую запись» в колонке «изменено» для au_id, который не присутствует в одной таблице, и присутствуют в другой таблице

CREATE TABLE authors 
(
au_id VARCHAR (100), 
au_lname VARCHAR (100), 
au_fname VARCHAR (100), 
phone VARCHAR (100), 
address VARCHAR (100), 
city VARCHAR (100), 
state VARCHAR (100), 
zip VARCHAR (100), 
[contract] VARCHAR (100) 
) 

INSERT authors 

SELECT '1', 'address', 'KALIA','29' ,'Second Avenue' ,  '9',' Second', 'Avenue','LALQUILA' UNION ALL 
SELECT '2', 'address', 'WALIA','279' ,'Hague Way',  '79', 'Hague', 'Way','QUTUBMINAR' UNION ALL 
SELECT '3', 'address', 'TOLIA','269', 'East Hague Street','69', 'East', 'Hague','Street' 

SELECT * FROM authors 
CREATE TABLE authorsCopy 
(
au_id VARCHAR (100), 
au_lname VARCHAR (100), 
au_Fname VARCHAR (100), 
phone VARCHAR (100), 
address VARCHAR (100), 
city VARCHAR (100), 
state VARCHAR (100), 
zip VARCHAR (100), 
[contract] VARCHAR (100) 
) 

INSERT authorsCopy 

SELECT '1', 'address', 'KALIA','29' ,'Second CHAIBASA' ,  '9',' Second', 'Avenue','LALQUILA' UNION ALL 
SELECT '2', 'address', 'WALIA','279' ,'Hague Way',  '79', 'Hague', 'Way','QUTUBMINAR' UNION ALL 
SELECT '3', 'address', 'TOLIA', '269', 'East Hague Street','69', 'East', 'Hague','Street' UNION ALL 
SELECT '4', 'address', 'MIR', '279' ,'TATANAGAR',  '79', 'Hague', 'Way','QUTUBMINAR' UNION ALL 
SELECT '5', 'address', 'WANGDU', '269', 'GHATSILA','69', 'East', 'Hague','Street' 

SELECT * FROM authorsCopy 


DECLARE @temp TABLE(au_id VARCHAR(11) PRIMARY KEY) /*this holds the primary keys of rows that have changed */ 
INSERT INTO @Temp(au_ID) --determine which rows have changed 
    SELECT au_ID 
    FROM --use the EXCEPT technique qhich is the quickest in our tests 
    (
    SELECT au_id, au_lname, au_fname, phone, [address], city, state, zip, [contract] 
    FROM authors 
     EXCEPT 
    SELECT au_id, au_lname, au_fname, phone, address, city, state, zip, contract 
    FROM authorsCopy 
)f--now we just SELECT those columns that have changed 
SELECT lefthand.au_id,lefthand.name,lefthand.value AS original,Righthand.value AS changed 
    FROM (--now we just lay out the two tables as key value pairs, using the string versions of the data 
    SELECT authors.au_id, 'au_lname' AS 'name',au_lname AS 'value' 
    FROM authors LEFT OUTER JOIN @Temp altered ON altered.au_id=authors.au_id 
    UNION 
    SELECT authors.au_id, 'au_fname' AS 'name',au_fname AS 'value' 
    FROM authors LEFT OUTER JOIN @Temp altered ON altered.au_id=authors.au_id 
    UNION 
    SELECT authors.au_id, 'phone',phone 
    FROM authors LEFT OUTER JOIN @Temp altered ON altered.au_id=authors.au_id 
    UNION 
    SELECT authors.au_id, 'address',address 
    FROM authors LEFT OUTER JOIN @Temp altered ON altered.au_id=authors.au_id 
    UNION 
    SELECT authors.au_id, 'City' AS 'name',City AS 'value' 
    FROM authors LEFT OUTER JOIN @Temp altered ON altered.au_id=authors.au_id 
    UNION 
    SELECT authors.au_id, 'State',state 
    FROM authors LEFT OUTER JOIN @Temp altered ON altered.au_id=authors.au_id 
    UNION 
    SELECT authors.au_id, 'zip',zip 
    FROM authors LEFT OUTER JOIN @Temp altered ON altered.au_id=authors.au_id 
    UNION 
    SELECT authors.au_id, 'contract',CONVERT(CHAR(1),contract) 
    FROM authors LEFT OUTER JOIN @Temp altered ON altered.au_id=authors.au_id) LeftHand 
    LEFT OUTER JOIN (
    SELECT authorsCopy.au_id, 'au_lname' AS 'name',au_lname AS 'value' 
    FROM authorsCopy LEFT OUTER JOIN @Temp altered ON altered.au_id=authorsCopy.au_id 
    UNION 
    SELECT authorsCopy.au_id, 'au_fname',au_fname 
    FROM authorsCopy LEFT OUTER JOIN @Temp altered ON altered.au_id=authorsCopy.au_id 
    UNION 
    SELECT authorsCopy.au_id, 'phone',phone 
    FROM authorsCopy LEFT OUTER JOIN @Temp altered ON altered.au_id=authorsCopy.au_id 
    UNION 
    SELECT authorsCopy.au_id, 'address',address 
    FROM authorsCopy LEFT OUTER JOIN @Temp altered ON altered.au_id=authorsCopy.au_id 
    UNION 
    SELECT authorsCopy.au_id, 'City' AS 'name',City AS 'value' 
    FROM authorsCopy LEFT OUTER JOIN @Temp altered ON altered.au_id=authorsCopy.au_id 
    UNION 
    SELECT authorsCopy.au_id, 'State',state 
    FROM authorsCopy LEFT OUTER JOIN @Temp altered ON altered.au_id=authorsCopy.au_id 
    UNION 
    SELECT authorsCopy.au_id, 'zip',zip 
    FROM authorsCopy LEFT OUTER JOIN @Temp altered ON altered.au_id=authorsCopy.au_id 
    UNION 
    SELECT authorsCopy.au_id, 'contract',CONVERT(CHAR(1),contract) 
    FROM authorsCopy LEFT OUTER JOIN @Temp altered ON altered.au_id=authorsCopy.au_id) rightHand 
     ON lefthand.au_ID=righthand.au_ID 
    AND lefthand.name=righthand.name 
    WHERE lefthand.value<>righthand.value 

Answer 1

sqldemon, я не собираюсь притворяйтесь, что мое решение красноречиво или фантастично, поскольку, безусловно, будут другие способы достижения такого же результата. Тем не менее, поскольку вы написали свой код в декларативном SQL, и вы не используете функции или хранимые процедуры, я собираюсь предположить, что вы ищете что-то простое и прямолинейное. Ниже приведен запрос, который будет возвращать значения бит, позволяющие определить, какие записи из таблицы Авторы являются новыми, а какие из них были каким-то образом изменены и идентифицировать столбцы, которые были изменены. Вы можете включить окончательный оператор выбора в другой CTE или загрузить его результаты во временную таблицу и использовать его для возврата того, что лучше всего подходит для вас (например, новые значения бок о бок со старыми значениями).

With New_Records as (
Select c.au_id 

From #authorsCopy c 
    Left Outer Join #authors a 
     on a.au_id = c.au_id 

Where a.au_id is null 
) 

Select a.au_id 
    , CAST(Case 
     When n.au_id is not null 
      Then 1 
      Else 0 
     End as bit) as new_record 
    , CAST(Case 
     When c.au_id is not null 
      Then 1 
      Else 0 
     End as bit) as changed_record 
    , CAST(Case 
     When a.au_fname <> c.au_Fname 
      Then 1 
      Else 0 
     End as bit) as au_fname_diff 
    , CAST(Case 
     When a.au_lname <> c.au_lname 
      Then 1 
      Else 0 
     End as bit) as au_lname_diff 
    , CAST(Case 
     When a.address <> c.address 
      Then 1 
      Else 0 
     End as bit) as address_diff 
    , CAST(Case 
     When a.city <> c.city 
      Then 1 
      Else 0 
     End as bit) as city_diff 
    , CAST(Case 
     When a.state <> c.state 
      Then 1 
      Else 0 
     End as bit) as state_diff 
    , CAST(Case 
     When a.phone <> c.phone 
      Then 1 
      Else 0 
     End as bit) as phone_diff 
    , CAST(Case 
     When a.contract <> c.contract 
      Then 1 
      Else 0 
     End as bit) as contract_diff 

From #authors a 
    Left Outer Join New_Records n 
     on a.au_id = n.au_id 
    Left Outer Join #authorsCopy c 
     on a.au_id = c.au_id 
      and (a.au_fname <> c.au_Fname 
       or a.au_lname <> c.au_lname 
       or a.address <> c.address 
       or a.city <> c.city 
       or a.state <> c.state 
       or a.zip <> c.zip 
       or a.phone <> c.phone 
       or a.contract <> c.contract)