使用 Nullif 作为条件的一部分
Using Nullif as part of a condition
我目前所处的场景是，我们有一个笨重、陈旧、庞大的数据库，为我们的一两个用户不太友好的系统提供支持（这是由第三方控制的，所以我不能改变那个）。
展望未来，我希望将必要的数据推送到一个新的（结构更好的）数据库中，并实施一种机制来保持两者之间的数据同步。
这个旧数据库的一个古怪特征是，它不使用空值，而是使用空字符串并将它们视为空值。
在新数据库中，我想在没有数据的地方使用空值（因为我想不出有什么好的理由不这样做）。
我的问题是当我将数据从旧数据库提取到新数据库时（使用 MERGE 语句），我正在使用 NULLIF([myCol], '') 来检查实际上是否有任何数据 -如果不是，则将其视为 null。
例如，在为学生同步数据时，我计划按照以下方式做一些事情（数据库和模式的名称与问题无关，所以我对结构进行了一些匿名处理） :
USE [NewDB];
DROP TABLE IF EXISTS #myTempTable;
SELECT *
INTO #myTempTable
FROM [OldDB].[schemaName].[Students];
MERGE [schema].[Person] p
USING #myTempTable s
ON TRIM(s.STUD_ISN) = p.StudentDBID
--WHEN MATCHED and not equal, update
WHEN NOT MATCHED
THEN INSERT (
[Surname] ,
[PreferredSurname] ,
[FormerSurname] ,
[Forename] ,
[MiddleNames] ,
[PreferredForename] ,
[DoB] ,
[Gender] ,
[GenderIdentity] ,
[Title] ,
[Deceased] ,
[DeceasedDate] ,
[StudentDBID])
VALUES (
NULLIF(TRIM([s].[STUD_Surname]), '') ,
NULLIF(TRIM([s].[STUD_Preferred_Surname]), '') ,
NULLIF(TRIM([s].STUD_Former_Surname), '') ,
NULLIF(TRIM([s].[STUD_Forename_1]), '') ,
NULLIF(TRIM([s].[STUD_Forename_2]), '') ,
NULLIF(TRIM([s].[STUD_Known_As]), '') ,
[s].[STUD_DOB] ,
NULLIF(TRIM([s].[STUD_Gender]), '') ,
NULLIF(TRIM([s].STUD_Gender_Identity), '') ,
NULLIF(TRIM([s].STUD_Title), '') ,
[s].STUD_Deceased ,
[s].STUD_Date_of_Death ,
TRIM([s].STUD_ISN)
);
现在，显然当前查询只处理以下场景：
The old database has data and the new one doesn't
因为我对以下场景的逻辑有些不满：
The new database has the corresponding record, but it needs updating.
对于基于文本的字段，有 3 种不同的情况需要更新“新”数据：
- 两个值都不是 null/empty，但它们不相等
- “旧”数据库中的记录是 null/empty 而“新”数据库中的记录不是
- “新”数据库中的记录为空，“旧”数据库中没有
我希望做一些相对简单的事情，例如：
WHEN MATCHED AND (
(NULLIF(TRIM([s].[STUD_Surname]), '') IS NOT NULL
AND p.Surname IS NULL)
OR (NULLIF(TRIM([s].[STUD_Surname]), '') IS NULL
AND p.Surname IS NOT NULL)
OR (NULLIF(TRIM([s].[STUD_Surname]), '') != p.Surname)
) -- do the same for the other columns
THEN UPDATE SET
Surname = s.STUD_Surname
但是，NULLIF(TRIM([s].[STUD_Surname]), '') IS NOT NULL显然无效？
我最好的选择是在 WHEN MATCHED 子句中将 NULLIF 换成 ISNULL ......还是我错过了一些可以提高效率的东西？
您可以使用 SQL 中可用的合并功能来获得所需的结果
它将return来自传递参数的第一个非空值
SELECT合并（空，'First Non Null'，'Alex'）
可以简化更新检查。
因为源温度 table 没有 NULL。
您只需要比较修剪后的值。
MERGE Person t
USING #tmpTable s
ON s.STUD_ISN = t.StudentDBID
WHEN NOT MATCHED THEN
INSERT (
StudentDBID
, Forename
, PreferredForename
, Surname
)
VALUES (
NULLIF(TRIM(s.STUD_ISN), '')
, NULLIF(TRIM(s.STUD_Forename), '')
, NULLIF(TRIM(s.STUD_Forename_1), '')
, NULLIF(TRIM(s.STUD_Surname), '')
)
WHEN MATCHED
AND (
COALESCE(t.Forename, '') != TRIM(s.STUD_Forename)
OR COALESCE(t.PreferredForename, '') != TRIM(s.STUD_Forename_1)
OR COALESCE(t.Surname, '') != TRIM(s.STUD_Surname)
)
THEN
UPDATE SET
UpdatedOn = SYSDATETIME()
, Forename = NULLIF(TRIM(s.STUD_Forename), '')
, PreferredForename = NULLIF(TRIM(s.STUD_Forename_1), '')
, Surname = NULLIF(TRIM(s.STUD_Surname), '')
;
SELECT *
FROM Person
StudentDBID | Forename | PreferredForename | Surname | UpdatedOn | CreatedOn
:---------- | :------- | :---------------- | :------ | :-------------------------- | :--------------------------
B9701 | Bob | Bobby | Modest | 2022-01-14 12:58:05.9862269 | 2022-01-14 12:58:05.9862269
J0402 | Jane | JD | Doe | 2022-01-14 12:58:05.9862269 | 2022-01-14 12:58:05.9862269
J0504 | Jim | Jimmy | Savage | null | 2022-01-14 12:58:05.9862269
J7201 | John | null | Doe | null | 2022-01-14 12:58:05.9862269
M0803 | Mike | null | Hammer | 2022-01-14 12:58:05.9862269 | 2022-01-14 12:58:05.9862269
演示 db<>fiddle here
最后，我的解决方案是在 SELECT .... Into .... 块中应用各种函数。像这样：
ALTER PROCEDURE [NGSync].[spFullStudentSync]
AS
BEGIN
SET NOCOUNT ON;
DROP TABLE IF EXISTS #students
SELECT [STUD_ISN],
NULLIF(TRIM([STUD_Student_ID]), '') AS [STUD_Student_ID] ,
NULLIF(TRIM([STUD_Surname]), '') AS [STUD_Surname] ,
NULLIF(TRIM([STUD_Forename_1]), '') AS [STUD_Forename_1] ,
NULLIF(TRIM([STUD_Forename_2]), '') AS [STUD_Forename_2] ,
NULLIF(TRIM([STUD_Known_As]), '') AS [STUD_Known_As] ,
[STUD_DOB] ,
NULLIF(TRIM([STUD_Gender]) , '') AS [STUD_Gender],
NULLIF(TRIM([STUD_Title]) , '') AS [STUD_Title],
NULLIF(TRIM([STUD_Ethnicity]) , '') AS [STUD_Ethnicity],
NULLIF(TRIM([STUD_LDDHP]) , '') AS [STUD_LDDHP],
NULLIF(TRIM([STUD_Home_Telephone_No] ) , '') AS [STUD_Home_Telephone_No] ,
NULLIF(TRIM([STUD_Daytime_Telephone] ) , '') AS [STUD_Daytime_Telephone] ,
NULLIF(TRIM([STUD_Mobile_Telephone] ) , '') AS [STUD_Mobile_Telephone] ,
NULLIF(TRIM([STUD_EMail_Address] ) , '') AS [STUD_EMail_Address] ,
NULLIF(TRIM([STUD_Former_Surname] ) , '') AS [STUD_Former_Surname] ,
CAST( CASE WHEN NULLIF(TRIM([STUD_Deceased] ) , '') = 'D' THEN 1 else 0 end AS bit ) AS [STUD_Deceased] ,
NULLIF(TRIM([STUD_Deletion_Flag] ) , '') AS [STUD_Deletion_Flag] ,
[STUD_Delete_Merge] ,
NULLIF(TRIM([STUD_Photo_filename] ) , '') AS [STUD_Photo_filename] ,
NULLIF(TRIM([STUD_Nationality] ) , '') AS [STUD_Nationality] ,
[STUD_Date_of_Entry_in_UK] ,
NULLIF(TRIM([STUD_Student_Type_FESR] ) , '') AS [STUD_Student_Type_FESR] ,
[STUD_School_ISN] ,
NULLIF(TRIM([STUD_Home_LEA] ) , '') AS [STUD_Home_LEA] ,
NULLIF(TRIM([STUD_Employer_Code] ) , '') AS [STUD_Employer_Code] ,
NULLIF(TRIM([STUD_Religion] ) , '') AS [STUD_Religion] ,
NULLIF(TRIM([STUD_Location] ) , '') AS [STUD_Location] ,
[STUD_TPS_Include] ,
[STUD_QOE_Complete] ,
NULLIF(TRIM([STUD_UCAS_Application_Code] ) , '') AS [STUD_UCAS_Application_Code] ,
[STUD_MIAP_Consent_Status] ,
[STUD_MIAP_Verification_Type] ,
NULLIF(TRIM([STUD_MIAP_Other_Verification] ) , '') AS [STUD_MIAP_Other_Verification] ,
NULLIF(TRIM([STUD_Bank_Sort_Code] ) , '') AS [STUD_Bank_Sort_Code] ,
NULLIF(TRIM([STUD_Bank_AC_No] ) , '') AS [STUD_Bank_AC_No] ,
[STUD_Bank_ISN] ,
NULLIF(TRIM([STUD_Bank_Postcode] ) , '') AS [STUD_Bank_Postcode] ,
NULLIF(TRIM([STUD_Bank_AC_Holders_Name] ) , '') AS [STUD_Bank_AC_Holders_Name] ,
NULLIF(TRIM([STUD_Current_Tutor_Group] ) , '') AS [STUD_Current_Tutor_Group] ,
NULLIF(TRIM([STUD_Current_PostCode] ) , '') AS [STUD_Current_PostCode] ,
NULLIF(TRIM([STUD_Doctor_Name] ) , '') AS [STUD_Doctor_Name] ,
NULLIF(TRIM([STUD_Doctor_Telephone] ) , '') AS [STUD_Doctor_Telephone] ,
[STUD_ULN] ,
NULLIF(TRIM([STUD_College_Email_Address] ) , '') AS [STUD_College_Email_Address] ,
[STUD_Date_Due_to_Leave_UK] ,
[STUD_UK_Residence] ,
NULLIF(TRIM([STUD_Parish] ) , '') AS [STUD_Parish] ,
NULLIF(TRIM([STUD_Area] ) , '') AS [STUD_Area] ,
[STUD_Bus_Pass] ,
NULLIF(TRIM([STUD_Bus_Route] ) , '') AS [STUD_Bus_Route] ,
[STUD_Eng_1st_Lang] ,
NULLIF(TRIM([STUD_Language] ) , '') AS [STUD_Language] ,
[STUD_High_Achiever] ,
[STUD_Is_Staff] ,
[STUD_Is_Staff_ISN] ,
[STUD_Excluded] ,
[STUD_RUI_3_no_contact] ,
[STUD_RUI_1_courses] ,
[STUD_RUI_2_surveys] ,
[STUD_PMC_C1_post] ,
[STUD_PMC_C2_phone] ,
[STUD_PMC_C3_email] ,
[STUD_Created_Date] ,
NULLIF(TRIM([STUD_Created_User] ) , '') AS [STUD_Created_User] ,
NULLIF(TRIM([STUD_Created_Prog] ) , '') AS [STUD_Created_Prog] ,
[STUD_Modified_Date] ,
NULLIF(TRIM([STUD_Modified_User] ) , '') AS [STUD_Modified_User] ,
NULLIF(TRIM([STUD_Modified_Prog] ) , '') AS [STUD_Modified_Prog] ,
[STUD_OK_to_use_Image] ,
NULLIF(TRIM([STUD_Sexual_Orientation] ) , '') AS [STUD_Sexual_Orientation] ,
NULLIF(TRIM([STUD_Gender_Identity] ) , '') AS [STUD_Gender_Identity] ,
[STUD_Visa_Proof_Produced] ,
[STUD_Visa_Proof_Produced_Date] ,
NULLIF(TRIM([STUD_Visa_Proof_Produced_Details] ) , '') AS [STUD_Visa_Proof_Produced_Details] ,
NULLIF(TRIM([STUD_Visa_Type] ) , '') AS [STUD_Visa_Type] ,
[STUD_Visa_Expiry_Date] ,
[STUD_Visa_Letter_Issued] ,
[STUD_Asylum_Seeker] ,
[STUD_Refugee] ,
[STUD_Entered_UK_for_Education] ,
[STUD_Restrictions_on_Stay] ,
NULLIF(TRIM([STUD_Add_To_Portal_Title_Bar] ) , '') AS [STUD_Add_To_Portal_Title_Bar] ,
[STUD_RUI_5] ,
NULLIF(TRIM([STUD_Visa_Reference]) , '') AS [STUD_Visa_Reference],
NULLIF(TRIM([STUD_Visa_Note] ) , '') AS [STUD_Visa_Note] ,
[STUD_FA_Bank_ISN] ,
NULLIF(TRIM([STUD_FA_Bank_Sort_Code] ) , '') AS [STUD_FA_Bank_Sort_Code] ,
NULLIF(TRIM([STUD_FA_Bank_AC_No] ) , '') AS [STUD_FA_Bank_AC_No] ,
NULLIF(TRIM([STUD_FA_Bank_AC_Holders_Name]) , '') AS [STUD_FA_Bank_AC_Holders_Name],
NULLIF(TRIM([STUD_Marital_Status] ) , '') AS [STUD_Marital_Status] ,
NULLIF(TRIM([STUD_Country_of_Birth] ) , '') AS [STUD_Country_of_Birth] ,
NULLIF(TRIM([STUD_On_Supervision] ) , '') AS [STUD_On_Supervision] ,
[STUD_S_IraqDEAS] ,
[STUD_S_Pending_SCN] ,
NULLIF(TRIM([STUD_Primary_LLDDCode] ) , '') AS [STUD_Primary_LLDDCode] ,
NULLIF(TRIM([STUD_A2C_Language] ) , '') AS [STUD_A2C_Language] ,
NULLIF(TRIM([STUD_Signature_Filename] ) , '') AS [STUD_Signature_Filename] ,
[STUD_S_ILA_Expiry_Date] ,
[STUD_Date_Of_Death] ,
[STUD_S_SQA_Exception] ,
NULLIF(TRIM([STUD_S_SQA_VID] ) , '') AS [STUD_S_SQA_VID] ,
[STUD_S_SQA_Registration_Date] ,
NULLIF(TRIM([STUD_FA_Bank_AC_Ref] ) , '') AS [STUD_FA_Bank_AC_Ref] ,
NULLIF(TRIM([STUD_Bank_AC_Ref] ) , '') AS [STUD_Bank_AC_Ref] ,
[STUD_Anonymised] ,
NULLIF(TRIM([STUD_Quarantine_Status] ) , '') AS [STUD_Quarantine_Status] ,
[STUD_KeycloakID] ,
NULLIF(TRIM([STUD_Preferred_Surname] ) , '') AS [STUD_Preferred_Surname] ,
[STUD_Exclude_From_Balancing] ,
NULLIF(TRIM([STUD_Corresp_Preference] ) , '') AS [STUD_Corresp_Preference] ,
NULLIF(TRIM([STUD_HESA_ID] ) , '') AS [STUD_HESA_ID] ,
NULLIF(TRIM([STUD_FEPUS_ID] ) , '') AS [STUD_FEPUS_ID] ,
NULLIF(TRIM([STUD_PEV_PIN] ) , '') AS [STUD_PEV_PIN] ,
NULLIF(TRIM([STUD_Photo_GUID_Filename] ) , '') AS [STUD_Photo_GUID_Filename]
INTO #students
FROM [NG].[dbo].[STUDstudent];
MERGE [people].[Person] AS [p]
USING #students AS [s]
ON [s].[STUD_ISN] = [p].[StudentDBID]
WHEN MATCHED
AND (
[s].[STUD_Surname] != [p].[Surname]
OR [s].[STUD_Preferred_Surname] != [p].[PreferredSurname]
OR [s].[STUD_Former_Surname] != [p].[FormerSurname]
OR [s].[STUD_Forename_1] != [p].[Forename]
OR [s].[STUD_Forename_2] != [p].[MiddleNames]
OR [s].[STUD_Known_As] != [p].[PreferredForename]
OR [s].[STUD_DoB] != [p].[DoB]
OR [s].[STUD_Gender] != [p].[Gender]
OR [s].[STUD_Gender_Identity] != [p].[GenderIdentity]
OR [s].[STUD_Title] != [p].[Title]
OR [s].[STUD_Deceased] != [p].[Deceased]
OR [s].[STUD_Date_of_Death] != [p].[DeceasedDate]
OR [s].[STUD_Is_Staff_ISN] != [p].[StaffDBID]
)
THEN UPDATE SET
[Surname] = [s].[STUD_Surname] ,
[PreferredSurname] = [s].[STUD_Preferred_Surname] ,
[FormerSurname] = [s].[STUD_Former_Surname],
[Forename] = [s].[STUD_Forename_1] ,
[MiddleNames] = [s].[STUD_Forename_2] ,
[PreferredForename] = [s].[STUD_Known_As],
[DoB] = [s].[STUD_DoB] ,
[Gender] = [s].[STUD_Gender] ,
[GenderIdentity] = [s].[STUD_Gender_Identity] ,
[Title] = [s].[STUD_Title] ,
[Deceased] = [s].[STUD_Deceased],
[StaffDBID] = [s].[STUD_Is_Staff_ISN]
WHEN NOT MATCHED
THEN INSERT (
[Surname] ,
[PreferredSurname] ,
[FormerSurname] ,
[Forename] ,
[MiddleNames] ,
[PreferredForename] ,
[DoB] ,
[Gender] ,
[GenderIdentity] ,
[Title] ,
[Deceased] ,
[DeceasedDate] ,
[StudentDBID] ,
[StaffDBID])
VALUES (
[s].[STUD_Surname] ,
[s].[STUD_Preferred_Surname] ,
[s].[STUD_Former_Surname] ,
[s].[STUD_Forename_1] ,
[s].[STUD_Forename_2] ,
[s].[STUD_Known_As] ,
[s].[STUD_DOB] ,
[s].[STUD_Gender] ,
[s].[STUD_Gender_Identity] ,
[s].[STUD_Title] ,
[s].[STUD_Deceased] ,
[s].[STUD_Date_of_Death] ,
[s].[STUD_ISN] ,
[s].[STuD_IS_Staff_ISN]
);
END
它可能会变得更有效率，但考虑到它将成为每晚任务的一部分，并且 运行 当人们不使用该系统时，它可以在大约 2 秒内处理大约 35000 条记录，所以它是“足够高效。
我目前所处的场景是，我们有一个笨重、陈旧、庞大的数据库，为我们的一两个用户不太友好的系统提供支持（这是由第三方控制的，所以我不能改变那个）。
展望未来，我希望将必要的数据推送到一个新的（结构更好的）数据库中，并实施一种机制来保持两者之间的数据同步。
这个旧数据库的一个古怪特征是，它不使用空值，而是使用空字符串并将它们视为空值。
在新数据库中，我想在没有数据的地方使用空值（因为我想不出有什么好的理由不这样做）。
我的问题是当我将数据从旧数据库提取到新数据库时（使用 MERGE 语句），我正在使用 NULLIF([myCol], '') 来检查实际上是否有任何数据 -如果不是，则将其视为 null。
例如，在为学生同步数据时，我计划按照以下方式做一些事情（数据库和模式的名称与问题无关，所以我对结构进行了一些匿名处理） :
USE [NewDB];
DROP TABLE IF EXISTS #myTempTable;
SELECT *
INTO #myTempTable
FROM [OldDB].[schemaName].[Students];
MERGE [schema].[Person] p
USING #myTempTable s
ON TRIM(s.STUD_ISN) = p.StudentDBID
--WHEN MATCHED and not equal, update
WHEN NOT MATCHED
THEN INSERT (
[Surname] ,
[PreferredSurname] ,
[FormerSurname] ,
[Forename] ,
[MiddleNames] ,
[PreferredForename] ,
[DoB] ,
[Gender] ,
[GenderIdentity] ,
[Title] ,
[Deceased] ,
[DeceasedDate] ,
[StudentDBID])
VALUES (
NULLIF(TRIM([s].[STUD_Surname]), '') ,
NULLIF(TRIM([s].[STUD_Preferred_Surname]), '') ,
NULLIF(TRIM([s].STUD_Former_Surname), '') ,
NULLIF(TRIM([s].[STUD_Forename_1]), '') ,
NULLIF(TRIM([s].[STUD_Forename_2]), '') ,
NULLIF(TRIM([s].[STUD_Known_As]), '') ,
[s].[STUD_DOB] ,
NULLIF(TRIM([s].[STUD_Gender]), '') ,
NULLIF(TRIM([s].STUD_Gender_Identity), '') ,
NULLIF(TRIM([s].STUD_Title), '') ,
[s].STUD_Deceased ,
[s].STUD_Date_of_Death ,
TRIM([s].STUD_ISN)
);
现在，显然当前查询只处理以下场景：
The old database has data and the new one doesn't
因为我对以下场景的逻辑有些不满：
The new database has the corresponding record, but it needs updating.
对于基于文本的字段，有 3 种不同的情况需要更新“新”数据：
- 两个值都不是 null/empty，但它们不相等
- “旧”数据库中的记录是 null/empty 而“新”数据库中的记录不是
- “新”数据库中的记录为空，“旧”数据库中没有
我希望做一些相对简单的事情，例如：
WHEN MATCHED AND (
(NULLIF(TRIM([s].[STUD_Surname]), '') IS NOT NULL
AND p.Surname IS NULL)
OR (NULLIF(TRIM([s].[STUD_Surname]), '') IS NULL
AND p.Surname IS NOT NULL)
OR (NULLIF(TRIM([s].[STUD_Surname]), '') != p.Surname)
) -- do the same for the other columns
THEN UPDATE SET
Surname = s.STUD_Surname
但是，NULLIF(TRIM([s].[STUD_Surname]), '') IS NOT NULL显然无效？
我最好的选择是在 WHEN MATCHED 子句中将 NULLIF 换成 ISNULL ......还是我错过了一些可以提高效率的东西？
您可以使用 SQL 中可用的合并功能来获得所需的结果
它将return来自传递参数的第一个非空值
SELECT合并（空，'First Non Null'，'Alex'）
可以简化更新检查。
因为源温度 table 没有 NULL。
您只需要比较修剪后的值。
MERGE Person t USING #tmpTable s ON s.STUD_ISN = t.StudentDBID WHEN NOT MATCHED THEN INSERT ( StudentDBID , Forename , PreferredForename , Surname ) VALUES ( NULLIF(TRIM(s.STUD_ISN), '') , NULLIF(TRIM(s.STUD_Forename), '') , NULLIF(TRIM(s.STUD_Forename_1), '') , NULLIF(TRIM(s.STUD_Surname), '') ) WHEN MATCHED AND ( COALESCE(t.Forename, '') != TRIM(s.STUD_Forename) OR COALESCE(t.PreferredForename, '') != TRIM(s.STUD_Forename_1) OR COALESCE(t.Surname, '') != TRIM(s.STUD_Surname) ) THEN UPDATE SET UpdatedOn = SYSDATETIME() , Forename = NULLIF(TRIM(s.STUD_Forename), '') , PreferredForename = NULLIF(TRIM(s.STUD_Forename_1), '') , Surname = NULLIF(TRIM(s.STUD_Surname), '') ;
SELECT * FROM PersonStudentDBID | Forename | PreferredForename | Surname | UpdatedOn | CreatedOn :---------- | :------- | :---------------- | :------ | :-------------------------- | :-------------------------- B9701 | Bob | Bobby | Modest | 2022-01-14 12:58:05.9862269 | 2022-01-14 12:58:05.9862269 J0402 | Jane | JD | Doe | 2022-01-14 12:58:05.9862269 | 2022-01-14 12:58:05.9862269 J0504 | Jim | Jimmy | Savage | null | 2022-01-14 12:58:05.9862269 J7201 | John | null | Doe | null | 2022-01-14 12:58:05.9862269 M0803 | Mike | null | Hammer | 2022-01-14 12:58:05.9862269 | 2022-01-14 12:58:05.9862269
演示 db<>fiddle here
最后，我的解决方案是在 SELECT .... Into .... 块中应用各种函数。像这样：
ALTER PROCEDURE [NGSync].[spFullStudentSync]
AS
BEGIN
SET NOCOUNT ON;
DROP TABLE IF EXISTS #students
SELECT [STUD_ISN],
NULLIF(TRIM([STUD_Student_ID]), '') AS [STUD_Student_ID] ,
NULLIF(TRIM([STUD_Surname]), '') AS [STUD_Surname] ,
NULLIF(TRIM([STUD_Forename_1]), '') AS [STUD_Forename_1] ,
NULLIF(TRIM([STUD_Forename_2]), '') AS [STUD_Forename_2] ,
NULLIF(TRIM([STUD_Known_As]), '') AS [STUD_Known_As] ,
[STUD_DOB] ,
NULLIF(TRIM([STUD_Gender]) , '') AS [STUD_Gender],
NULLIF(TRIM([STUD_Title]) , '') AS [STUD_Title],
NULLIF(TRIM([STUD_Ethnicity]) , '') AS [STUD_Ethnicity],
NULLIF(TRIM([STUD_LDDHP]) , '') AS [STUD_LDDHP],
NULLIF(TRIM([STUD_Home_Telephone_No] ) , '') AS [STUD_Home_Telephone_No] ,
NULLIF(TRIM([STUD_Daytime_Telephone] ) , '') AS [STUD_Daytime_Telephone] ,
NULLIF(TRIM([STUD_Mobile_Telephone] ) , '') AS [STUD_Mobile_Telephone] ,
NULLIF(TRIM([STUD_EMail_Address] ) , '') AS [STUD_EMail_Address] ,
NULLIF(TRIM([STUD_Former_Surname] ) , '') AS [STUD_Former_Surname] ,
CAST( CASE WHEN NULLIF(TRIM([STUD_Deceased] ) , '') = 'D' THEN 1 else 0 end AS bit ) AS [STUD_Deceased] ,
NULLIF(TRIM([STUD_Deletion_Flag] ) , '') AS [STUD_Deletion_Flag] ,
[STUD_Delete_Merge] ,
NULLIF(TRIM([STUD_Photo_filename] ) , '') AS [STUD_Photo_filename] ,
NULLIF(TRIM([STUD_Nationality] ) , '') AS [STUD_Nationality] ,
[STUD_Date_of_Entry_in_UK] ,
NULLIF(TRIM([STUD_Student_Type_FESR] ) , '') AS [STUD_Student_Type_FESR] ,
[STUD_School_ISN] ,
NULLIF(TRIM([STUD_Home_LEA] ) , '') AS [STUD_Home_LEA] ,
NULLIF(TRIM([STUD_Employer_Code] ) , '') AS [STUD_Employer_Code] ,
NULLIF(TRIM([STUD_Religion] ) , '') AS [STUD_Religion] ,
NULLIF(TRIM([STUD_Location] ) , '') AS [STUD_Location] ,
[STUD_TPS_Include] ,
[STUD_QOE_Complete] ,
NULLIF(TRIM([STUD_UCAS_Application_Code] ) , '') AS [STUD_UCAS_Application_Code] ,
[STUD_MIAP_Consent_Status] ,
[STUD_MIAP_Verification_Type] ,
NULLIF(TRIM([STUD_MIAP_Other_Verification] ) , '') AS [STUD_MIAP_Other_Verification] ,
NULLIF(TRIM([STUD_Bank_Sort_Code] ) , '') AS [STUD_Bank_Sort_Code] ,
NULLIF(TRIM([STUD_Bank_AC_No] ) , '') AS [STUD_Bank_AC_No] ,
[STUD_Bank_ISN] ,
NULLIF(TRIM([STUD_Bank_Postcode] ) , '') AS [STUD_Bank_Postcode] ,
NULLIF(TRIM([STUD_Bank_AC_Holders_Name] ) , '') AS [STUD_Bank_AC_Holders_Name] ,
NULLIF(TRIM([STUD_Current_Tutor_Group] ) , '') AS [STUD_Current_Tutor_Group] ,
NULLIF(TRIM([STUD_Current_PostCode] ) , '') AS [STUD_Current_PostCode] ,
NULLIF(TRIM([STUD_Doctor_Name] ) , '') AS [STUD_Doctor_Name] ,
NULLIF(TRIM([STUD_Doctor_Telephone] ) , '') AS [STUD_Doctor_Telephone] ,
[STUD_ULN] ,
NULLIF(TRIM([STUD_College_Email_Address] ) , '') AS [STUD_College_Email_Address] ,
[STUD_Date_Due_to_Leave_UK] ,
[STUD_UK_Residence] ,
NULLIF(TRIM([STUD_Parish] ) , '') AS [STUD_Parish] ,
NULLIF(TRIM([STUD_Area] ) , '') AS [STUD_Area] ,
[STUD_Bus_Pass] ,
NULLIF(TRIM([STUD_Bus_Route] ) , '') AS [STUD_Bus_Route] ,
[STUD_Eng_1st_Lang] ,
NULLIF(TRIM([STUD_Language] ) , '') AS [STUD_Language] ,
[STUD_High_Achiever] ,
[STUD_Is_Staff] ,
[STUD_Is_Staff_ISN] ,
[STUD_Excluded] ,
[STUD_RUI_3_no_contact] ,
[STUD_RUI_1_courses] ,
[STUD_RUI_2_surveys] ,
[STUD_PMC_C1_post] ,
[STUD_PMC_C2_phone] ,
[STUD_PMC_C3_email] ,
[STUD_Created_Date] ,
NULLIF(TRIM([STUD_Created_User] ) , '') AS [STUD_Created_User] ,
NULLIF(TRIM([STUD_Created_Prog] ) , '') AS [STUD_Created_Prog] ,
[STUD_Modified_Date] ,
NULLIF(TRIM([STUD_Modified_User] ) , '') AS [STUD_Modified_User] ,
NULLIF(TRIM([STUD_Modified_Prog] ) , '') AS [STUD_Modified_Prog] ,
[STUD_OK_to_use_Image] ,
NULLIF(TRIM([STUD_Sexual_Orientation] ) , '') AS [STUD_Sexual_Orientation] ,
NULLIF(TRIM([STUD_Gender_Identity] ) , '') AS [STUD_Gender_Identity] ,
[STUD_Visa_Proof_Produced] ,
[STUD_Visa_Proof_Produced_Date] ,
NULLIF(TRIM([STUD_Visa_Proof_Produced_Details] ) , '') AS [STUD_Visa_Proof_Produced_Details] ,
NULLIF(TRIM([STUD_Visa_Type] ) , '') AS [STUD_Visa_Type] ,
[STUD_Visa_Expiry_Date] ,
[STUD_Visa_Letter_Issued] ,
[STUD_Asylum_Seeker] ,
[STUD_Refugee] ,
[STUD_Entered_UK_for_Education] ,
[STUD_Restrictions_on_Stay] ,
NULLIF(TRIM([STUD_Add_To_Portal_Title_Bar] ) , '') AS [STUD_Add_To_Portal_Title_Bar] ,
[STUD_RUI_5] ,
NULLIF(TRIM([STUD_Visa_Reference]) , '') AS [STUD_Visa_Reference],
NULLIF(TRIM([STUD_Visa_Note] ) , '') AS [STUD_Visa_Note] ,
[STUD_FA_Bank_ISN] ,
NULLIF(TRIM([STUD_FA_Bank_Sort_Code] ) , '') AS [STUD_FA_Bank_Sort_Code] ,
NULLIF(TRIM([STUD_FA_Bank_AC_No] ) , '') AS [STUD_FA_Bank_AC_No] ,
NULLIF(TRIM([STUD_FA_Bank_AC_Holders_Name]) , '') AS [STUD_FA_Bank_AC_Holders_Name],
NULLIF(TRIM([STUD_Marital_Status] ) , '') AS [STUD_Marital_Status] ,
NULLIF(TRIM([STUD_Country_of_Birth] ) , '') AS [STUD_Country_of_Birth] ,
NULLIF(TRIM([STUD_On_Supervision] ) , '') AS [STUD_On_Supervision] ,
[STUD_S_IraqDEAS] ,
[STUD_S_Pending_SCN] ,
NULLIF(TRIM([STUD_Primary_LLDDCode] ) , '') AS [STUD_Primary_LLDDCode] ,
NULLIF(TRIM([STUD_A2C_Language] ) , '') AS [STUD_A2C_Language] ,
NULLIF(TRIM([STUD_Signature_Filename] ) , '') AS [STUD_Signature_Filename] ,
[STUD_S_ILA_Expiry_Date] ,
[STUD_Date_Of_Death] ,
[STUD_S_SQA_Exception] ,
NULLIF(TRIM([STUD_S_SQA_VID] ) , '') AS [STUD_S_SQA_VID] ,
[STUD_S_SQA_Registration_Date] ,
NULLIF(TRIM([STUD_FA_Bank_AC_Ref] ) , '') AS [STUD_FA_Bank_AC_Ref] ,
NULLIF(TRIM([STUD_Bank_AC_Ref] ) , '') AS [STUD_Bank_AC_Ref] ,
[STUD_Anonymised] ,
NULLIF(TRIM([STUD_Quarantine_Status] ) , '') AS [STUD_Quarantine_Status] ,
[STUD_KeycloakID] ,
NULLIF(TRIM([STUD_Preferred_Surname] ) , '') AS [STUD_Preferred_Surname] ,
[STUD_Exclude_From_Balancing] ,
NULLIF(TRIM([STUD_Corresp_Preference] ) , '') AS [STUD_Corresp_Preference] ,
NULLIF(TRIM([STUD_HESA_ID] ) , '') AS [STUD_HESA_ID] ,
NULLIF(TRIM([STUD_FEPUS_ID] ) , '') AS [STUD_FEPUS_ID] ,
NULLIF(TRIM([STUD_PEV_PIN] ) , '') AS [STUD_PEV_PIN] ,
NULLIF(TRIM([STUD_Photo_GUID_Filename] ) , '') AS [STUD_Photo_GUID_Filename]
INTO #students
FROM [NG].[dbo].[STUDstudent];
MERGE [people].[Person] AS [p]
USING #students AS [s]
ON [s].[STUD_ISN] = [p].[StudentDBID]
WHEN MATCHED
AND (
[s].[STUD_Surname] != [p].[Surname]
OR [s].[STUD_Preferred_Surname] != [p].[PreferredSurname]
OR [s].[STUD_Former_Surname] != [p].[FormerSurname]
OR [s].[STUD_Forename_1] != [p].[Forename]
OR [s].[STUD_Forename_2] != [p].[MiddleNames]
OR [s].[STUD_Known_As] != [p].[PreferredForename]
OR [s].[STUD_DoB] != [p].[DoB]
OR [s].[STUD_Gender] != [p].[Gender]
OR [s].[STUD_Gender_Identity] != [p].[GenderIdentity]
OR [s].[STUD_Title] != [p].[Title]
OR [s].[STUD_Deceased] != [p].[Deceased]
OR [s].[STUD_Date_of_Death] != [p].[DeceasedDate]
OR [s].[STUD_Is_Staff_ISN] != [p].[StaffDBID]
)
THEN UPDATE SET
[Surname] = [s].[STUD_Surname] ,
[PreferredSurname] = [s].[STUD_Preferred_Surname] ,
[FormerSurname] = [s].[STUD_Former_Surname],
[Forename] = [s].[STUD_Forename_1] ,
[MiddleNames] = [s].[STUD_Forename_2] ,
[PreferredForename] = [s].[STUD_Known_As],
[DoB] = [s].[STUD_DoB] ,
[Gender] = [s].[STUD_Gender] ,
[GenderIdentity] = [s].[STUD_Gender_Identity] ,
[Title] = [s].[STUD_Title] ,
[Deceased] = [s].[STUD_Deceased],
[StaffDBID] = [s].[STUD_Is_Staff_ISN]
WHEN NOT MATCHED
THEN INSERT (
[Surname] ,
[PreferredSurname] ,
[FormerSurname] ,
[Forename] ,
[MiddleNames] ,
[PreferredForename] ,
[DoB] ,
[Gender] ,
[GenderIdentity] ,
[Title] ,
[Deceased] ,
[DeceasedDate] ,
[StudentDBID] ,
[StaffDBID])
VALUES (
[s].[STUD_Surname] ,
[s].[STUD_Preferred_Surname] ,
[s].[STUD_Former_Surname] ,
[s].[STUD_Forename_1] ,
[s].[STUD_Forename_2] ,
[s].[STUD_Known_As] ,
[s].[STUD_DOB] ,
[s].[STUD_Gender] ,
[s].[STUD_Gender_Identity] ,
[s].[STUD_Title] ,
[s].[STUD_Deceased] ,
[s].[STUD_Date_of_Death] ,
[s].[STUD_ISN] ,
[s].[STuD_IS_Staff_ISN]
);
END
它可能会变得更有效率，但考虑到它将成为每晚任务的一部分，并且 运行 当人们不使用该系统时，它可以在大约 2 秒内处理大约 35000 条记录，所以它是“足够高效。