Version Control Inside SQL Server

Yulia : So, who changed my procedure yesterday?
Lyosha : not me
Maxim : not me
- Guys, can we get Git?
Seryozha : it's time!
2 weeks have passed…

Yulia : children?
- Yul, and you did not commit?
Yulia : no damn (...

That's how it all started. Well, what, every character and every line commit?
')
Or maybe all this will happen by itself?) At this point, they start to come to my head
DDL-triggers , Temporal table and the picture is folded. Resolved, we will store versions inside
SQL Server'a !)




To begin with we create tables in which versions will be stored

USE master GO --     IF NOT EXISTS ( SELECT 1 FROM sys.objects WHERE name = 'VersionControlHistory' AND type = 'U' ) CREATE TABLE dbo.VersionControlHistory( Id INT NOT NULL, Event sysname NOT NULL, Db sysname NOT NULL, Sch sysname NOT NULL, Object sysname NOT NULL, Sql XML NOT NULL, Login sysname NOT NULL, StartDate DATETIME2(0) NOT NULL, EndDate DATETIME2(0) NOT NULL ) ON [PRIMARY] TEXTIMAGE_ON [PRIMARY] GO --      IF NOT EXISTS ( SELECT 1 FROM sys.objects WHERE name = 'VersionControl' AND type = 'U' ) CREATE TABLE dbo.VersionControl( Id INT IDENTITY(1,1) NOT NULL CONSTRAINT PK_VersionControl PRIMARY KEY NONCLUSTERED, Event sysname NOT NULL, Db sysname NOT NULL, Sch sysname NOT NULL, Object sysname NOT NULL, Sql XML NOT NULL, Login sysname NOT NULL, StartDate DATETIME2(0) GENERATED ALWAYS AS ROW START NOT NULL, EndDate DATETIME2(0) GENERATED ALWAYS AS ROW END NOT NULL, PERIOD FOR SYSTEM_TIME (StartDate, EndDate) ) WITH ( SYSTEM_VERSIONING = ON ( HISTORY_TABLE = dbo.VersionControlHistory ) ) GO 

It is important to keep in mind the limitations of the Temporal table.

1. After creating them, you cannot use the DDL command either on the main table or on the historical tables. And you can not delete Temporal table
2. You can not change the data in the historical table

The second limitation suits us, but what to do with the first?

The algorithm is as follows:

 --        ALTER TABLE dbo.VersionControl SET ( SYSTEM_VERSIONING = OFF ); /* -  */ --    : ALTER TABLE dbo.VersionControl SET ( SYSTEM_VERSIONING = ON ( HISTORY_TABLE = dbo.VersionControlHistory, DATA_CONSISTENCY_CHECK = OFF ); 

While there are no indexes on the table yet, we will fill it with our procedures, functions, etc., marked INIT , which in our case will mean initial placement

 DECLARE @query NVARCHAR(MAX), @template NVARCHAR(MAX) = N' USE [db] INSERT INTO MASTER.dbo.VersionControl WITH (TABLOCKX) ( Event, Db, Sch, Object, Sql, Login ) SELECT ''INIT'' AS Event, DB_NAME(), ss.name AS Sch, so.name AS Object, CONCAT(''<query><![CDATA['', sasm.definition, '']]></query>'' ), SUSER_SNAME() AS Login FROM sys.objects AS so JOIN sys.schemas AS ss ON ss.schema_id = so.schema_id JOIN sys.all_sql_modules AS sasm ON sasm.object_id = so.object_id WHERE so.is_ms_shipped = 0 AND NOT EXISTS ( SELECT 1 FROM MASTER.dbo.VersionControl AS vc WHERE vc.Db = ''[db]'' AND vc.Sch = ss.name AND vc.Object = so.name ); '; DECLARE @databases TABLE (rn INT, Name sysname); INSERT @databases (rn, Name) SELECT ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) AS rn, name FROM sys.databases WHERE owner_sid != 0x01; DECLARE @i INT = 1, @max INT = (SELECT MAX(rn) FROM @databases), @error NVARCHAR(128), @db sysname; WHILE @i < @max BEGIN SELECT @query = REPLACE(@template, '[db]', Name), @db = Name FROM @databases WHERE rn = @i; BEGIN TRY EXECUTE sp_executesql @query; SET @i += 1; CONTINUE; END TRY BEGIN CATCH SET @error = CONCAT( 'XML Parsing error. In this case that''s mean one of [', @db, '] object is invalid for convert to XML' ); PRINT @error; SET @i += 1; CONTINUE; END CATCH; END; GO 

Since Changes to objects will occur with the UPDATE statement , and we will most often look at the versions by key: database, schema, and object name, the index suggests!

 IF NOT EXISTS ( SELECT 1 FROM sys.indexes WHERE name = 'IX_VersionControl_upd_key' ) CREATE UNIQUE NONCLUSTERED INDEX IX_VersionControl_upd_key ON MASTER.dbo.VersionControl (Db, Sch, Object) INCLUDE (Sql, Event, Login); 

Everything is ready to start storing versions and help us with this DDL trigger.

Important! Since tables for versions are in the master database, after creating the trigger, all those who do not have rights to this database will not be able to change, create and delete objects

 IF EXISTS ( SELECT 1 FROM sys.server_triggers WHERE name = 'tr_VersionControl' ) DROP TRIGGER tr_VersionControl ON ALL SERVER GO CREATE TRIGGER tr_VersionControl ON ALL SERVER --WITH ENCRYPTION --   /*      : https://docs.microsoft.com/ru-ru/sql/relational-databases/triggers/ddl-events?view=sql-server-2017 */ FOR CREATE_TABLE, ALTER_TABLE, DROP_TABLE, CREATE_VIEW, ALTER_VIEW, DROP_VIEW, CREATE_FUNCTION, ALTER_FUNCTION, DROP_FUNCTION, CREATE_PROCEDURE, ALTER_PROCEDURE, DROP_PROCEDURE, CREATE_ASSEMBLY, ALTER_ASSEMBLY, DROP_ASSEMBLY, CREATE_INDEX, ALTER_INDEX, DROP_INDEX, CREATE_TRIGGER, ALTER_TRIGGER, DROP_TRIGGER, RENAME AS BEGIN SET NOCOUNT ON; UPDATE vs SET vs.Event = ev.EventType, vs.Sql = CONCAT('<query><!CDATA', ev.Sql, '></query>' ), vs.Login = ev.Login FROM MASTER.dbo.VersionControl AS vs JOIN ( SELECT * FROM ( VALUES ( EVENTDATA().value( '(/EVENT_INSTANCE/EventType)[1]', 'NVARCHAR(128)' ), EVENTDATA().value( '(/EVENT_INSTANCE/SchemaName)[1]', 'NVARCHAR(128)' ), EVENTDATA().value( '(/EVENT_INSTANCE/ObjectName)[1]', 'NVARCHAR(128)' ), EVENTDATA().value( '(/EVENT_INSTANCE/TSQLCommand/CommandText)[1]', 'NVARCHAR(MAX)' ), EVENTDATA().value( '(/EVENT_INSTANCE/LoginName)[1]', 'NVARCHAR(128)' ) )) AS Event (EventType, Sch, Object, Sql, Login ) ) ev ON vs.Db = DB_NAME() AND vs.Sch = ev.Sch AND vs.Object = ev.Object ; END GO 

And for ease of use of this system the procedure is proposed below.

It is easy to use. The sp_ prefix will help us access the procedure without specifying the database and schema. Parameters are filled intuitively. You can specify only the database and we will see objects associated only with it for all the time, but it is possible both the schema and the object itself and of course the time range for which changes have been made.

 CREATE PROCEDURE dbo.sp_Vc @db sysname = '%', @sch sysname = '%', @obj sysname = '%', @from DATETIME2(0) = NULL, @to DATETIME2(0) = NULL AS BEGIN SET NOCOUNT ON; IF @from IS NULL AND @to IS NULL BEGIN SELECT * FROM master.dbo.VersionControl WHERE Db LIKE @db AND Sch LIKE @sch AND Object LIKE @obj ORDER BY StartDate DESC END ELSE BEGIN SELECT * FROM master.dbo.VersionControl FOR SYSTEM_TIME BETWEEN @from AND @to WHERE Db LIKE @db AND Sch LIKE @sch AND Object LIKE @obj ORDER BY StartDate DESC END END GO 

Below are examples of using the procedure.

 --        sp_Vc; /*          */ sp_Vc 'dwh'; /*            */ sp_Vc 'dwh', 'dbo'; /*      ,        */ sp_Vc 'dwh', 'dbo', 'MyObject'; /*      , ,       1-  9-  */ sp_Vc 'dwh', 'dbo', 'MyObject', '20180501 00:00:00', '20180509 00:00:00'; 

You can install this microform from my repository , and if your version of SQL Sever is under 2016, then you should go here . By the way, we are using this version now, but it is not so cool.

Finally

I never managed to defeat the conclusion & _gt; and & _lt; instead of the > and < signs from the master.dbo.VersionControl table by the Sql field. If you can help with this or you have ideas, wait for Pull Request .

Thank you for your time, put stars, hearts and arrows up.