比较 C# 中的两个 SQL Server 数据库架构

Question

我正在发布我的 Windows 应用程序的更新版本。新版本中有数据库架构更改。我也不想丢失数据。

所以我采取的方法是在保留数据库的同时替换 dll。为了升级数据库，我打算比较旧数据库的数据库架构并进行必要的更改。

那么，我如何将旧数据库结构（模式）与新数据库结构（模式）进行比较，以及如何检测更改并纠正它。到目前为止，我尝试使用GetSchema 方法获取数据库模式。

但由于新架构是预定义的，我如何将新架构注入程序并与安装旧架构的站点中的现有架构进行比较。

Answer 1

这是一种比较数据库的免费方法。

下面是我敲出来的一个 SQL Server 脚本，它将你数据库的存储过程、视图和表的内容输出到输出窗口中。

你可以通过调用来运行它：

exec [dbo].[ScriptStoredProcedures]

在我的许多项目中，我会运行这个脚本，将文本复制到我的 Visual Studio 项目中的一个文件中，这样我就可以签入我们的数据库在特定时间查看的副本。

（是的，您也可以在 Visual Studio 中创建数据库项目，但这是另一种方法。）

如果您在两个数据库上运行此脚本，则可以比较两个输出以找出差异。

CREATE PROCEDURE [dbo].[ScriptStoredProcedures]
AS
BEGIN
    --
    --  Attempt to create a long SQL script, to Drop, then "CREATE PROCEDURE" on all SPs and "CREATE FUNCTION" on all Functions in this database. 
    --
    --  You can then run this script on a "target" database, and it'll have the latest Stored Procedures & functions
    --  created/updated on it.
    --
    --      exec [dbo].[ScriptStoredProcedures]
    --  
    SET NOCOUNT ON

    PRINT '--'
    PRINT '--  SQL Script, generated by the [ScriptStoredProcedures] Stored Procedure.'
    PRINT '--  Created on ' + convert(nvarchar, GetDate(), 106) + ' ' + convert(nvarchar, GetDate(), 108)
    PRINT '--'
    PRINT '--  This will create/update the Stored Procedures on this database, to bring them up-to-date with the SPs '
    PRINT '--  from the database ''' + DB_NAME() + ''' on the server ''' + @@SERVERNAME + ''''
    PRINT '--'
    PRINT '--'



    --  Create a temporary table, where each record contains one line of Stored Procedure/Function script
    --  (i.e. If you have a Stored Procedure with 30 lines of script in it, we'll create 30 temporary records
    --  to store it)
    CREATE TABLE #tmp 
    (
        [inx] INT IDENTITY(1, 1),
        [text] nvarchar(4000)
    )

    DECLARE @StoredProcedureName NVARCHAR(200)
    DECLARE @StoredProcedureType NVARCHAR(10)
    DECLARE @ExecCommand NVARCHAR(200)
    DECLARE @OneLineOfScript NVARCHAR(4000)

    --  First, get a list of all Stored Procedures & Functions in this database
    DECLARE cursorEachStoredProcedure CURSOR LOCAL FORWARD_ONLY STATIC READ_ONLY FOR 
    SELECT [name],              --  Name of the Stored Procedure or Function
           [type]               --  This will contain "FN" if it's a Function, or "P" if it's a Stored Procedure
    FROM sysobjects 
    WHERE (OBJECTPROPERTY(id, N'IsProcedure') = 1
      OR OBJECTPROPERTY(id, N'IsTableFunction') = 1
      OR OBJECTPROPERTY(id, N'IsScalarFunction') = 1
      OR OBJECTPROPERTY(id, N'IsView') = 1)
    AND [name] NOT LIKE 'sp_%'
    AND [name] NOT LIKE 'fn_%'
    ORDER BY [type] DESC,       --  Sort by Stored Procedures first, then functions
             [name]             --  then show the list of SPs/Functions in name order


    OPEN cursorEachStoredProcedure 
    FETCH NEXT FROM cursorEachStoredProcedure INTO @StoredProcedureName, @StoredProcedureType

    --  For each Stored Procedure we've found in our database, create some script to delete the Stored Procedure
    --  from the target database if it exists, then re-create it.
    WHILE (@@FETCH_STATUS = 0) 
    BEGIN 

        PRINT ''
        IF (@StoredProcedureType = 'P')
        BEGIN
            PRINT 'PRINT ''Creating stored procedure: ''''' + @StoredProcedureName + ''''''''
            PRINT ''
            PRINT 'IF EXISTS(select Name from sysobjects where OBJECTPROPERTY(id, N''IsProcedure'') = 1 AND Name = ''' + @StoredProcedureName + ''')'
            PRINT 'BEGIN'
            PRINT '   DROP PROCEDURE [' + @StoredProcedureName + '] '
            PRINT 'END'
        END
        ELSE
        IF (@StoredProcedureType = 'V')
        BEGIN
            PRINT 'PRINT ''Creating view: ''''' + @StoredProcedureName + ''''''''
            PRINT ''
            PRINT 'IF EXISTS(select Name from sysobjects where OBJECTPROPERTY(id, N''IsView'') = 1 AND Name = ''' + @StoredProcedureName + ''')'
            PRINT 'BEGIN'
            PRINT '   DROP VIEW [' + @StoredProcedureName + '] '
            PRINT 'END'
        END
        ELSE
        BEGIN
            PRINT 'PRINT ''Creating function: ''''' + @StoredProcedureName + ''''''''
            PRINT ''
            PRINT 'IF EXISTS(select Name from sysobjects where (OBJECTPROPERTY(id, N''IsTableFunction'') = 1 OR OBJECTPROPERTY(id, N''IsScalarFunction'') = 1) AND Name = ''' + @StoredProcedureName + ''')'
            PRINT 'BEGIN'
            PRINT '   DROP FUNCTION [' + @StoredProcedureName + '] '
            PRINT 'END'
        END         
        PRINT 'GO '

        --  Run the "sp_helptext" command, to get the text of this Stored Procedure (one row per *line* of script)
        --  and store this set of results in a temporary table, so we can step through, line-by-line, and send
        --  the output to the Messages window.
        SET @ExecCommand = 'sp_helptext @objname = ''' + @StoredProcedureName + ''''

        DELETE FROM #tmp

        INSERT INTO #tmp
        EXEC(@ExecCommand)

        --  Step through each line of this Stored Procedure
        DECLARE cursorEachLineOfScript CURSOR LOCAL FORWARD_ONLY STATIC READ_ONLY FOR 
        SELECT [text] 
        FROM #tmp
        ORDER BY [inx]

        OPEN cursorEachLineOfScript 
        FETCH NEXT FROM cursorEachLineOfScript INTO @OneLineOfScript

        WHILE (@@FETCH_STATUS = 0) 
        BEGIN 
            --  For each line of Stored Procedure script, send the text to the Messages window
            PRINT @OneLineOfScript

            FETCH NEXT FROM cursorEachLineOfScript INTO @OneLineOfScript
        END 
        CLOSE cursorEachLineOfScript 
        DEALLOCATE cursorEachLineOfScript   
        PRINT 'GO '

        FETCH NEXT FROM cursorEachStoredProcedure INTO @StoredProcedureName, @StoredProcedureType
    END

    CLOSE cursorEachStoredProcedure 
    DEALLOCATE cursorEachStoredProcedure    

    DROP TABLE #tmp 

    PRINT 'EXEC [dbo].[spGrantExectoAllStoredProcs]'
    PRINT 'GO'

    PRINT '--'
    PRINT '--'
    PRINT '--  List of tables (and their fields) in this database'
    PRINT '--'
    PRINT '--'
    PRINT '--'


    --  First, let's iterate through our list of tables, and find out which fields they contain.
    DECLARE 
        @tableName nvarchar(200),
        @fieldName nvarchar(500),
        @fieldType nvarchar(500),
        @fieldNullable nvarchar(200)

    DECLARE cursorTables CURSOR LOCAL FORWARD_ONLY STATIC READ_ONLY FOR 
    SELECT st.NAME as 'Table_name'
    FROM sys.tables st
    ORDER BY 1

    OPEN cursorTables 
    FETCH NEXT FROM cursorTables INTO @tableName

    WHILE (@@FETCH_STATUS = 0) 
    BEGIN
        PRINT '--  Table: ' + @tableName

        DECLARE cursorFields CURSOR LOCAL FORWARD_ONLY STATIC READ_ONLY FOR 
        SELECT sc.NAME as 'Field_name',
            case when t.Name in ('char', 'varchar', 'nvarchar') 
           then t.Name + '(' + cast(sc.max_length/2 as nvarchar) + ')' 
           else 
                case when t.Name in ('numeric') 
                    then t.Name + '(' + cast(sc.precision as nvarchar)  + ',' + cast(sc.scale as nvarchar) + ')'  
                    else t.Name 
                end
        end as 'Data_type',
        case when sc.is_nullable=1 then 'null' else 'not null' end as 'Nullable'
        FROM sys.tables st
        INNER JOIN sys.columns sc ON st.object_id = sc.object_id
        INNER JOIN sys.types t ON sc.system_type_id = t.system_type_id
        WHERE t.Name != 'sysname'
        AND st.name = @tableName
        ORDER BY 1, 2

        OPEN cursorFields 
        FETCH NEXT FROM cursorFields INTO @fieldName, @fieldType, @fieldNullable

        WHILE (@@FETCH_STATUS = 0) 
        BEGIN
            PRINT '--    ' + @fieldName + '  (' + @fieldType + ', ' + @fieldNullable + ')'
            FETCH NEXT FROM cursorFields INTO @fieldName, @fieldType, @fieldNullable
        END
        CLOSE cursorFields 
        DEALLOCATE cursorFields 

        PRINT '--'

        FETCH NEXT FROM cursorTables INTO @tableName
    END
    CLOSE cursorTables 
    DEALLOCATE cursorTables 
END

Answer 2

我们使用 RedGate 的 SQL Compare，但它并不是特别便宜。

SQL Compare

这让我们可以比较两个数据库的结构，并创建一个 SQL 脚本来更新其中一个数据库以匹配另一个。

Answer 3

创建您的Database Migration 脚本并使用Db Up 等工具运行它们以跟踪架构更改。 SQL 脚本将您的数据库从版本 1 迁移到 2、2 到 3 等。Schema Compare 是previous question 中提到的另一个选项。

• 修改客户表.sql
• 更新 Settings.sql

Answer 4

两个建议。

1. 使用 Redgate（我为之工作）提供的 SQL 比较 SDK。这允许您以编程方式访问 SQL 比较技术。
2. 您必须检查特定架构版本的特征以确定它是哪一个？如果是这样，您可以针对该版本运行适当的脚本以将其带到下一个版本。您的安装程序只需要包含一系列此类迁移脚本，这些脚本会连续运行以将其带到下一个增量版本。理想情况下，您可以通过扩展属性或版本表将版本信息嵌入架构中，并在成功应用迁移脚本后更新。