SQL Server Convert Table Contents into Merge Statement?
If I understand you correctly you have a table in one environment (lets call it DEV) and you want to update in another (lets call it PROD). For obvious reasons you're not allowed to connect these two via a DB link.
The best option might be to
- BCP the contents of your DEV table to a file
- BCP the file into a staging table in PROD
- Write a single merge statement that inserts/updates/delete your values from your staging table.
- Clear/drop the staging table
The nice thing about this is that if you do this regularly its easy to repeat with different source files.
Of course SSIS or Redgate Data Compare would make this much easier if you have access to and are allowed to use these tools.
This helper script takes a table name as a parameter and produces a MERGE statement containing the data. It installs a stored procedure within [master] as a system object, allowing the proc to be called from all databases (e.g. EXEC Northwind.dbo.sp_generate_merge 'Region')
This approach (which originally I posted on SQL Server Central ) caters for result sets greater than 8,000 chars in length, something we tend to hit at the 100 row mark.
It also supports including/excluding specific columns as well as conditionally updating matched rows if the source data has changed.
UPDATED 2012-09-27 Changed the proc to use Nathan's improved Xml output method of generating the MERGE statement, which gets around the character limit issue at both the row and resultset level.
UPDATED 2013-04-22 Fix for xml character issue reported by Dave
UPDATED 2013-04-22 This script is now on GitHub: https://github.com/readyroll/generate-sql-merge
SET NOCOUNT ON
GO
PRINT 'Using Master database'
USE master
GO
PRINT 'Checking for the existence of this procedure'
IF (SELECT OBJECT_ID('sp_generate_merge','P')) IS NOT NULL --means, the procedure already exists
BEGIN
PRINT 'Procedure already exists. So, dropping it'
DROP PROC sp_generate_merge
END
GO
--Turn system object marking on
CREATE PROC sp_generate_merge
(
@table_name varchar(776), -- The table/view for which the MERGE statement will be generated using the existing data
@target_table varchar(776) = NULL, -- Use this parameter to specify a different table name into which the data will be inserted/updated/deleted
@from varchar(800) = NULL, -- Use this parameter to filter the rows based on a filter condition (using WHERE)
@include_timestamp bit = 0, -- Specify 1 for this parameter, if you want to include the TIMESTAMP/ROWVERSION column's data in the MERGE statement
@debug_mode bit = 0, -- If @debug_mode is set to 1, the SQL statements constructed by this procedure will be printed for later examination
@schema varchar(64) = NULL, -- Use this parameter if you are not the owner of the table
@ommit_images bit = 0, -- Use this parameter to generate MERGE statement by omitting the 'image' columns
@ommit_identity bit = 0, -- Use this parameter to ommit the identity columns
@top int = NULL, -- Use this parameter to generate a MERGE statement only for the TOP n rows
@cols_to_include varchar(8000) = NULL, -- List of columns to be included in the MERGE statement
@cols_to_exclude varchar(8000) = NULL, -- List of columns to be excluded from the MERGE statement
@update_only_if_changed bit = 1, -- When 1, only performs an UPDATE operation if an included column in a matched row has changed.
@disable_constraints bit = 0, -- When 1, disables foreign key constraints and enables them after the MERGE statement
@ommit_computed_cols bit = 0, -- When 1, computed columns will not be included in the MERGE statement
@include_use_db bit = 1, -- When 1, includes a USE [DatabaseName] statement at the beginning of the generated batch
@results_to_text bit = 0 -- When 1, outputs results to grid/messages window. When 0, outputs MERGE statement in an XML fragment.
)
AS
BEGIN
/***********************************************************************************************************
Procedure: sp_generate_merge (Version 0.93)
(Adapted by Daniel Nolan for SQL Server 2008/2012)
Adapted from: sp_generate_inserts (Build 22)
(Copyright © 2002 Narayana Vyas Kondreddi. All rights reserved.)
Purpose: To generate a MERGE statement from existing data, which will INSERT/UPDATE/DELETE data based
on matching primary key values in the source/target table.
The generated statements can be executed to replicate the data in some other location.
Written by: Narayana Vyas Kondreddi
http://vyaskn.tripod.com
Daniel Nolan
http://danere.com
@dan3r3
Example 1: To generate a MERGE statement for table 'titles':
EXEC sp_generate_merge 'titles'
Example 2: To generate a MERGE statement for 'titlesCopy' table from 'titles' table:
EXEC sp_generate_merge 'titles', 'titlesCopy'
Example 3: To generate a MERGE statement for table 'titles' that will unconditionally UPDATE matching rows
(ie. not perform a "has data changed?" check prior to going ahead with an UPDATE):
EXEC sp_generate_merge 'titles', @update_only_if_changed = 0
Example 4: To generate a MERGE statement for 'titles' table for only those titles
which contain the word 'Computer' in them:
NOTE: Do not complicate the FROM or WHERE clause here. It's assumed that you are good with T-SQL if you are using this parameter
EXEC sp_generate_merge 'titles', @from = "from titles where title like '%Computer%'"
Example 5: To specify that you want to include TIMESTAMP column's data as well in the MERGE statement:
(By default TIMESTAMP column's data is not scripted)
EXEC sp_generate_merge 'titles', @include_timestamp = 1
Example 6: To print the debug information:
EXEC sp_generate_merge 'titles', @debug_mode = 1
Example 7: If the table is in a different schema to the default, use @schema parameter to specify the schema name
To use this option, you must have SELECT permissions on that table
EXEC sp_generate_merge 'Nickstable', @schema = 'Nick'
Example 8: To generate a MERGE statement for the rest of the columns excluding images
EXEC sp_generate_merge 'imgtable', @ommit_images = 1
Example 9: To generate a MERGE statement excluding (omitting) IDENTITY columns:
(By default IDENTITY columns are included in the MERGE statement)
EXEC sp_generate_merge 'mytable', @ommit_identity = 1
Example 10: To generate a MERGE statement for the TOP 10 rows in the table:
EXEC sp_generate_merge 'mytable', @top = 10
Example 11: To generate a MERGE statement with only those columns you want:
EXEC sp_generate_merge 'titles', @cols_to_include = "'title','title_id','au_id'"
Example 12: To generate a MERGE statement by omitting certain columns:
EXEC sp_generate_merge 'titles', @cols_to_exclude = "'title','title_id','au_id'"
Example 13: To avoid checking the foreign key constraints while loading data with a MERGE statement:
EXEC sp_generate_merge 'titles', @disable_constraints = 1
Example 14: To exclude computed columns from the MERGE statement:
EXEC sp_generate_merge 'MyTable', @ommit_computed_cols = 1
***********************************************************************************************************/
SET NOCOUNT ON
--Making sure user only uses either @cols_to_include or @cols_to_exclude
IF ((@cols_to_include IS NOT NULL) AND (@cols_to_exclude IS NOT NULL))
BEGIN
RAISERROR('Use either @cols_to_include or @cols_to_exclude. Do not use both the parameters at once',16,1)
RETURN -1 --Failure. Reason: Both @cols_to_include and @cols_to_exclude parameters are specified
END
--Making sure the @cols_to_include and @cols_to_exclude parameters are receiving values in proper format
IF ((@cols_to_include IS NOT NULL) AND (PATINDEX('''%''',@cols_to_include) = 0))
BEGIN
RAISERROR('Invalid use of @cols_to_include property',16,1)
PRINT 'Specify column names surrounded by single quotes and separated by commas'
PRINT 'Eg: EXEC sp_generate_merge titles, @cols_to_include = "''title_id'',''title''"'
RETURN -1 --Failure. Reason: Invalid use of @cols_to_include property
END
IF ((@cols_to_exclude IS NOT NULL) AND (PATINDEX('''%''',@cols_to_exclude) = 0))
BEGIN
RAISERROR('Invalid use of @cols_to_exclude property',16,1)
PRINT 'Specify column names surrounded by single quotes and separated by commas'
PRINT 'Eg: EXEC sp_generate_merge titles, @cols_to_exclude = "''title_id'',''title''"'
RETURN -1 --Failure. Reason: Invalid use of @cols_to_exclude property
END
--Checking to see if the database name is specified along wih the table name
--Your database context should be local to the table for which you want to generate a MERGE statement
--specifying the database name is not allowed
IF (PARSENAME(@table_name,3)) IS NOT NULL
BEGIN
RAISERROR('Do not specify the database name. Be in the required database and just specify the table name.',16,1)
RETURN -1 --Failure. Reason: Database name is specified along with the table name, which is not allowed
END
--Checking for the existence of 'user table' or 'view'
--This procedure is not written to work on system tables
--To script the data in system tables, just create a view on the system tables and script the view instead
IF @schema IS NULL
BEGIN
IF NOT EXISTS (SELECT 1 FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_NAME = @table_name AND (TABLE_TYPE = 'BASE TABLE' OR TABLE_TYPE = 'VIEW') AND TABLE_SCHEMA = SCHEMA_NAME())
BEGIN
RAISERROR('User table or view not found.',16,1)
PRINT 'You may see this error if the specified table is not in your default schema (' + SCHEMA_NAME() + '). In that case use @schema parameter to specify the schema name.'
PRINT 'Make sure you have SELECT permission on that table or view.'
RETURN -1 --Failure. Reason: There is no user table or view with this name
END
END
ELSE
BEGIN
IF NOT EXISTS (SELECT 1 FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_NAME = @table_name AND (TABLE_TYPE = 'BASE TABLE' OR TABLE_TYPE = 'VIEW') AND TABLE_SCHEMA = @schema)
BEGIN
RAISERROR('User table or view not found.',16,1)
PRINT 'Make sure you have SELECT permission on that table or view.'
RETURN -1 --Failure. Reason: There is no user table or view with this name
END
END
--Variable declarations
DECLARE @Column_ID int,
@Column_List varchar(8000),
@Column_List_For_Update varchar(8000),
@Column_List_For_Check varchar(8000),
@Column_Name varchar(128),
@Column_Name_Unquoted varchar(128),
@Data_Type varchar(128),
@Actual_Values nvarchar(max), --This is the string that will be finally executed to generate a MERGE statement
@IDN varchar(128), --Will contain the IDENTITY column's name in the table
@Target_Table_For_Output varchar(776),
@Source_Table_Qualified varchar(776)
--Variable Initialization
SET @IDN = ''
SET @Column_ID = 0
SET @Column_Name = ''
SET @Column_Name_Unquoted = ''
SET @Column_List = ''
SET @Column_List_For_Update = ''
SET @Column_List_For_Check = ''
SET @Actual_Values = ''
--Variable Defaults
IF @schema IS NULL
BEGIN
SET @Target_Table_For_Output = QUOTENAME(COALESCE(@target_table, @table_name))
END
ELSE
BEGIN
SET @Target_Table_For_Output = QUOTENAME(@schema) + '.' + QUOTENAME(COALESCE(@target_table, @table_name))
END
SET @Source_Table_Qualified = QUOTENAME(COALESCE(@schema,SCHEMA_NAME())) + '.' + QUOTENAME(@table_name)
--To get the first column's ID
SELECT @Column_ID = MIN(ORDINAL_POSITION)
FROM INFORMATION_SCHEMA.COLUMNS (NOLOCK)
WHERE TABLE_NAME = @table_name
AND TABLE_SCHEMA = COALESCE(@schema, SCHEMA_NAME())
--Loop through all the columns of the table, to get the column names and their data types
WHILE @Column_ID IS NOT NULL
BEGIN
SELECT @Column_Name = QUOTENAME(COLUMN_NAME),
@Column_Name_Unquoted = COLUMN_NAME,
@Data_Type = DATA_TYPE
FROM INFORMATION_SCHEMA.COLUMNS (NOLOCK)
WHERE ORDINAL_POSITION = @Column_ID
AND TABLE_NAME = @table_name
AND TABLE_SCHEMA = COALESCE(@schema, SCHEMA_NAME())
IF @cols_to_include IS NOT NULL --Selecting only user specified columns
BEGIN
IF CHARINDEX( '''' + SUBSTRING(@Column_Name,2,LEN(@Column_Name)-2) + '''',@cols_to_include) = 0
BEGIN
GOTO SKIP_LOOP
END
END
IF @cols_to_exclude IS NOT NULL --Selecting only user specified columns
BEGIN
IF CHARINDEX( '''' + SUBSTRING(@Column_Name,2,LEN(@Column_Name)-2) + '''',@cols_to_exclude) <> 0
BEGIN
GOTO SKIP_LOOP
END
END
--Making sure to output SET IDENTITY_INSERT ON/OFF in case the table has an IDENTITY column
IF (SELECT COLUMNPROPERTY( OBJECT_ID(@Source_Table_Qualified),SUBSTRING(@Column_Name,2,LEN(@Column_Name) - 2),'IsIdentity')) = 1
BEGIN
IF @ommit_identity = 0 --Determing whether to include or exclude the IDENTITY column
SET @IDN = @Column_Name
ELSE
GOTO SKIP_LOOP
END
--Making sure whether to output computed columns or not
IF @ommit_computed_cols = 1
BEGIN
IF (SELECT COLUMNPROPERTY( OBJECT_ID(@Source_Table_Qualified),SUBSTRING(@Column_Name,2,LEN(@Column_Name) - 2),'IsComputed')) = 1
BEGIN
GOTO SKIP_LOOP
END
END
--Tables with columns of IMAGE data type are not supported for obvious reasons
IF(@Data_Type in ('image'))
BEGIN
IF (@ommit_images = 0)
BEGIN
RAISERROR('Tables with image columns are not supported.',16,1)
PRINT 'Use @ommit_images = 1 parameter to generate a MERGE for the rest of the columns.'
RETURN -1 --Failure. Reason: There is a column with image data type
END
ELSE
BEGIN
GOTO SKIP_LOOP
END
END
--Determining the data type of the column and depending on the data type, the VALUES part of
--the MERGE statement is generated. Care is taken to handle columns with NULL values. Also
--making sure, not to lose any data from flot, real, money, smallmomey, datetime columns
SET @Actual_Values = @Actual_Values +
CASE
WHEN @Data_Type IN ('char','nchar')
THEN
'COALESCE('''''''' + REPLACE(RTRIM(' + @Column_Name + '),'''''''','''''''''''')+'''''''',''NULL'')'
WHEN @Data_Type IN ('varchar','nvarchar')
THEN
'COALESCE('''''''' + REPLACE(' + @Column_Name + ','''''''','''''''''''')+'''''''',''NULL'')'
WHEN @Data_Type IN ('datetime','smalldatetime','datetime2')
THEN
'COALESCE('''''''' + RTRIM(CONVERT(char,' + @Column_Name + ',127))+'''''''',''NULL'')'
WHEN @Data_Type IN ('uniqueidentifier')
THEN
'COALESCE('''''''' + REPLACE(CONVERT(char(255),RTRIM(' + @Column_Name + ')),'''''''','''''''''''')+'''''''',''NULL'')'
WHEN @Data_Type IN ('text')
THEN
'COALESCE('''''''' + REPLACE(CONVERT(varchar(max),' + @Column_Name + '),'''''''','''''''''''')+'''''''',''NULL'')'
WHEN @Data_Type IN ('ntext')
THEN
'COALESCE('''''''' + REPLACE(CONVERT(nvarchar(max),' + @Column_Name + '),'''''''','''''''''''')+'''''''',''NULL'')'
WHEN @Data_Type IN ('binary','varbinary')
THEN
'COALESCE(RTRIM(CONVERT(char,' + 'CONVERT(int,' + @Column_Name + '))),''NULL'')'
WHEN @Data_Type IN ('timestamp','rowversion')
THEN
CASE
WHEN @include_timestamp = 0
THEN
'''DEFAULT'''
ELSE
'COALESCE(RTRIM(CONVERT(char,' + 'CONVERT(int,' + @Column_Name + '))),''NULL'')'
END
WHEN @Data_Type IN ('float','real','money','smallmoney')
THEN
'COALESCE(LTRIM(RTRIM(' + 'CONVERT(char, ' + @Column_Name + ',2)' + ')),''NULL'')'
ELSE
'COALESCE(LTRIM(RTRIM(' + 'CONVERT(char, ' + @Column_Name + ')' + ')),''NULL'')'
END + '+' + ''',''' + ' + '
--Generating the column list for the MERGE statement
SET @Column_List = @Column_List + @Column_Name + ','
--Don't update Primary Key or Identity columns
IF NOT EXISTS(
SELECT 1
FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS pk ,
INFORMATION_SCHEMA.KEY_COLUMN_USAGE c
WHERE pk.TABLE_NAME = @table_name
AND pk.TABLE_SCHEMA = COALESCE(@schema, SCHEMA_NAME())
AND CONSTRAINT_TYPE = 'PRIMARY KEY'
AND c.TABLE_NAME = pk.TABLE_NAME
AND c.TABLE_SCHEMA = pk.TABLE_SCHEMA
AND c.CONSTRAINT_NAME = pk.CONSTRAINT_NAME
AND c.COLUMN_NAME = @Column_Name_Unquoted
)
BEGIN
SET @Column_List_For_Update = @Column_List_For_Update + @Column_Name + ' = Source.' + @Column_Name + ',
'
SET @Column_List_For_Check = @Column_List_For_Check +
CASE @Data_Type
WHEN 'text' THEN CHAR(10) + CHAR(9) + 'NULLIF(CAST(Source.' + @Column_Name + ' AS VARCHAR(MAX)), CAST(Target.' + @Column_Name + ' AS VARCHAR(MAX))) IS NOT NULL OR NULLIF(CAST(Target.' + @Column_Name + ' AS VARCHAR(MAX)), CAST(Source.' + @Column_Name + ' AS VARCHAR(MAX))) IS NOT NULL OR '
WHEN 'ntext' THEN CHAR(10) + CHAR(9) + 'NULLIF(CAST(Source.' + @Column_Name + ' AS NVARCHAR(MAX)), CAST(Target.' + @Column_Name + ' AS NVARCHAR(MAX))) IS NOT NULL OR NULLIF(CAST(Target.' + @Column_Name + ' AS NVARCHAR(MAX)), CAST(Source.' + @Column_Name + ' AS NVARCHAR(MAX))) IS NOT NULL OR '
ELSE CHAR(10) + CHAR(9) + 'NULLIF(Source.' + @Column_Name + ', Target.' + @Column_Name + ') IS NOT NULL OR NULLIF(Target.' + @Column_Name + ', Source.' + @Column_Name + ') IS NOT NULL OR '
END
END
SKIP_LOOP: --The label used in GOTO
SELECT @Column_ID = MIN(ORDINAL_POSITION)
FROM INFORMATION_SCHEMA.COLUMNS (NOLOCK)
WHERE TABLE_NAME = @table_name
AND TABLE_SCHEMA = COALESCE(@schema, SCHEMA_NAME())
AND ORDINAL_POSITION > @Column_ID
END --Loop ends here!
--To get rid of the extra characters that got concatenated during the last run through the loop
IF LEN(@Column_List_For_Update) <> 0
BEGIN
SET @Column_List_For_Update = ' ' + LEFT(@Column_List_For_Update,len(@Column_List_For_Update) - 4)
END
IF LEN(@Column_List_For_Check) <> 0
BEGIN
SET @Column_List_For_Check = LEFT(@Column_List_For_Check,len(@Column_List_For_Check) - 3)
END
SET @Actual_Values = LEFT(@Actual_Values,len(@Actual_Values) - 6)
SET @Column_List = LEFT(@Column_List,len(@Column_List) - 1)
IF LEN(LTRIM(@Column_List)) = 0
BEGIN
RAISERROR('No columns to select. There should at least be one column to generate the output',16,1)
RETURN -1 --Failure. Reason: Looks like all the columns are ommitted using the @cols_to_exclude parameter
END
--Get the join columns ----------------------------------------------------------
DECLARE @PK_column_list VARCHAR(8000)
DECLARE @PK_column_joins VARCHAR(8000)
SET @PK_column_list = ''
SET @PK_column_joins = ''
SELECT @PK_column_list = @PK_column_list + c.COLUMN_NAME + ', '
, @PK_column_joins = @PK_column_joins + 'Target.[' + c.COLUMN_NAME + '] = Source.[' + c.COLUMN_NAME + '] AND '
FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS pk ,
INFORMATION_SCHEMA.KEY_COLUMN_USAGE c
WHERE pk.TABLE_NAME = @table_name
AND pk.TABLE_SCHEMA = COALESCE(@schema, SCHEMA_NAME())
AND CONSTRAINT_TYPE = 'PRIMARY KEY'
AND c.TABLE_NAME = pk.TABLE_NAME
AND c.TABLE_SCHEMA = pk.TABLE_SCHEMA
AND c.CONSTRAINT_NAME = pk.CONSTRAINT_NAME
IF IsNull(@PK_column_list, '') = ''
BEGIN
RAISERROR('Table has no primary keys. There should at least be one column in order to have a valid join.',16,1)
RETURN -1 --Failure. Reason: looks like table doesn't have any primary keys
END
SET @PK_column_list = LEFT(@PK_column_list, LEN(@PK_column_list) -1)
SET @PK_column_joins = LEFT(@PK_column_joins, LEN(@PK_column_joins) -4)
--Forming the final string that will be executed, to output the a MERGE statement
SET @Actual_Values =
'SELECT ' +
CASE WHEN @top IS NULL OR @top < 0 THEN '' ELSE ' TOP ' + LTRIM(STR(@top)) + ' ' END +
'''' +
' '' + CASE WHEN ROW_NUMBER() OVER (ORDER BY ' + @PK_column_list + ') = 1 THEN '' '' ELSE '','' END + ''(''+ ' + @Actual_Values + '+'')''' + ' ' +
COALESCE(@from,' FROM ' + @Source_Table_Qualified + ' (NOLOCK)')
DECLARE @output VARCHAR(MAX) = ''
DECLARE @b CHAR(1) = CHAR(13)
--Determining whether to ouput any debug information
IF @debug_mode =1
BEGIN
SET @output += @b + '/*****START OF DEBUG INFORMATION*****'
SET @output += @b + ''
SET @output += @b + 'The primary key column list:'
SET @output += @b + @PK_column_list
SET @output += @b + ''
SET @output += @b + 'The INSERT column list:'
SET @output += @b + @Column_List
SET @output += @b + ''
SET @output += @b + 'The UPDATE column list:'
SET @output += @b + @Column_List_For_Update
SET @output += @b + ''
SET @output += @b + 'The SELECT statement executed to generate the MERGE:'
SET @output += @b + @Actual_Values
SET @output += @b + ''
SET @output += @b + '*****END OF DEBUG INFORMATION*****/'
SET @output += @b + ''
END
IF (@include_use_db = 1)
BEGIN
DECLARE @db varchar(120);
SET @db = 'USE ' + DB_NAME();
SET @output += @b + @db;
SET @output += @b + 'GO';
SET @output += @b + '';
END
SET @output += @b + '--MERGE generated by ''sp_generate_merge'' stored procedure, Version 0.93'
SET @output += @b + '--Originally by Vyas (http://vyaskn.tripod.com): sp_generate_inserts (build 22)'
SET @output += @b + '--Adapted for SQL Server 2008/2012 by Daniel Nolan (http://danere.com)'
SET @output += @b + ''
SET @output += @b + 'SET NOCOUNT ON'
SET @output += @b + ''
--Determining whether to print IDENTITY_INSERT or not
IF (LEN(@IDN) <> 0)
BEGIN
SET @output += @b + 'SET IDENTITY_INSERT ' + @Target_Table_For_Output + ' ON'
SET @output += @b + ''
END
--Temporarily disable constraints on the target table
IF @disable_constraints = 1 AND (OBJECT_ID(@Source_Table_Qualified, 'U') IS NOT NULL)
BEGIN
SET @output += @b + 'ALTER TABLE ' + @Target_Table_For_Output + ' NOCHECK CONSTRAINT ALL' --Code to disable constraints temporarily
END
--Output the start of the MERGE statement, qualifying with the schema name only if the caller explicitly specified it
SET @output += @b + 'MERGE INTO ' + @Target_Table_For_Output + ' AS Target'
SET @output += @b + 'USING (VALUES'
--All the hard work pays off here!!! You'll get your MERGE statement, when the next line executes!
DECLARE @tab TABLE (val NVARCHAR(max));
INSERT INTO @tab
EXEC (@Actual_Values)
SET @output += CAST((SELECT @b + val FROM @tab FOR XML PATH('')) AS XML).value('.', 'VARCHAR(MAX)');
--Output the columns to correspond with each of the values above--------------------
SET @output += @b + ') AS Source (' + @Column_List + ')'
--Output the join columns ----------------------------------------------------------
SET @output += @b + 'ON (' + @PK_column_joins + ')'
--When matched, perform an UPDATE on any metadata columns only (ie. not on PK)------
IF LEN(@Column_List_For_Update) <> 0
BEGIN
SET @output += @b + 'WHEN MATCHED ' + CASE WHEN @update_only_if_changed = 1 THEN 'AND (' + @Column_List_For_Check + ') ' ELSE '' END + 'THEN'
SET @output += @b + ' UPDATE SET'
SET @output += @b + @Column_List_For_Update
END
--When NOT matched by target, perform an INSERT------------------------------------
SET @output += @b + 'WHEN NOT MATCHED BY TARGET THEN';
SET @output += @b + ' INSERT(' + @Column_List + ')'
SET @output += @b + ' VALUES(' + REPLACE(@Column_List, '[', 'Source.[') + ')'
--When NOT matched by source, DELETE the row
SET @output += @b + 'WHEN NOT MATCHED BY SOURCE THEN '
SET @output += @b + ' DELETE;'
SET @output += @b + ''
SET @output += @b + 'GO'
--Display the number of affected rows to the user, or report if an error occurred---
SET @output += @b + 'DECLARE @mergeError int'
SET @output += @b + ' , @mergeCount int'
SET @output += @b + 'SELECT @mergeError = @@ERROR, @mergeCount = @@ROWCOUNT'
SET @output += @b + 'IF @mergeError != 0'
SET @output += @b + ' BEGIN'
SET @output += @b + ' PRINT ''ERROR OCCURRED IN MERGE FOR ' + @Target_Table_For_Output + '. Rows affected: '' + CAST(@mergeCount AS VARCHAR(100)); -- SQL should always return zero rows affected';
SET @output += @b + ' END'
SET @output += @b + 'ELSE'
SET @output += @b + ' BEGIN'
SET @output += @b + ' PRINT ''' + @Target_Table_For_Output + ' rows affected by MERGE: '' + CAST(@mergeCount AS VARCHAR(100));';
SET @output += @b + ' END'
SET @output += @b + 'GO'
SET @output += @b + ''
--Re-enable the previously disabled constraints-------------------------------------
IF @disable_constraints = 1 AND (OBJECT_ID(@Source_Table_Qualified, 'U') IS NOT NULL)
BEGIN
SET @output += @b + 'ALTER TABLE ' + @Target_Table_For_Output + ' CHECK CONSTRAINT ALL' --Code to enable the previously disabled constraints
SET @output += @b + 'GO'
END
--Switch-off identity inserting------------------------------------------------------
IF (LEN(@IDN) <> 0)
BEGIN
SET @output += @b + 'SET IDENTITY_INSERT ' + @Target_Table_For_Output + ' OFF'
SET @output += @b + 'GO'
END
SET @output += @b + 'SET NOCOUNT OFF'
SET @output += @b + 'GO'
SET @output += @b + ''
SET @output += @b + ''
IF @results_to_text = 1
BEGIN
--output the statement to the Grid/Messages tab
SELECT @output;
END
ELSE
BEGIN
--output the statement as xml (to overcome SSMS 4000/8000 char limitation)
SELECT [processing-instruction(x)]=@output FOR XML PATH(''),TYPE;
PRINT 'MERGE statement has been wrapped in an XML fragment and output successfully.'
PRINT 'Ensure you have Results to Grid enabled and then click the hyperlink to copy the statement within the fragment.'
PRINT ''
PRINT 'If you would prefer to have results output directly (without XML) specify @results_to_text = 1, however please'
PRINT 'note that the results may be truncated by your SQL client to 4000 nchars.'
END
SET NOCOUNT OFF
RETURN 0 --Success. We are done!
END
GO
PRINT 'Created the procedure'
GO
--Mark the proc as a system object to allow it to be called transparently from other databases
EXEC sp_MS_marksystemobject sp_generate_merge
GO
PRINT 'Granting EXECUTE permission on sp_generate_merge to all users'
GRANT EXEC ON sp_generate_merge TO public
SET NOCOUNT OFF
GO
PRINT 'Done'
Usage
- Ensure that your SQL client is configured to send results to grid.
- Execute the proc, providing the source table name as a parameter
- Click the hyperlink within the resultset.
- Copy the SQL (excluding the Output tags) and paste into a new query window to execute.
Example
To generate a MERGE statement containing all data within the Person.AddressType table, excluding the ModifiedDate and rowguid columns:
EXEC AdventureWorks.dbo.sp_generate_merge @schema = 'Person', @table_name ='AddressType', @cols_to_exclude = '''ModifiedDate'',''rowguid'''
Generated SQL:
SET NOCOUNT ON
GO
SET IDENTITY_INSERT [Person].[AddressType] ON
GO
MERGE INTO [Person].[AddressType] AS Target
USING (VALUES
---------------------------------------------------------------------------------------------------------------
(1,'Billing')
,(2,'Home')
,(3,'Main Office')
,(4,'Primary')
,(5,'Shipping')
,(6,'Contact')
) AS Source ([AddressTypeID],[Name])
ON (Target.[AddressTypeID] = Source.[AddressTypeID])
WHEN MATCHED AND (
NULLIF(Source.[Name], Target.[Name]) IS NOT NULL OR NULLIF(Target.[Name], Source.[Name]) IS NOT NULL) THEN
UPDATE SET
[Name] = Source.[Name]
WHEN NOT MATCHED BY TARGET THEN
INSERT([AddressTypeID],[Name])
VALUES(Source.[AddressTypeID],Source.[Name])
WHEN NOT MATCHED BY SOURCE THEN
DELETE;
SET IDENTITY_INSERT [Person].[AddressType] OFF
GO
SET NOCOUNT OFF
GO
I use this helper script to manage small lookup tables between environments. 80k rows isn't huge by any means but it is not insignificant. Conrad has laid out a solid plan for moving large amounts of data.
If you do choose to go the generated merge route hopefully this helps you:
declare @TableName nvarchar(128) = 'dbo.YourTable';
--// do not modify
set nocount on;
if ( isnull(parsename(@TableName, 1), '') = '' or
isnull(parsename(@TableName, 2), '') = ''
)
begin
raiserror('@TableName should be in form of owner.object (dbo.Yak). Cannot continue.', 16, 1, @TableName);
return;
end
if object_id(@TableName) is null
begin
raiserror('Table [%s] not found. Cannot continue.', 16, 1, @TableName);
return;
end
if objectproperty(object_id(@TableName), N'TableHasPrimaryKey') = 0
begin
raiserror('Table [%s] has no primary key defined. Cannot continue.', 16, 1, @TableName);
return;
end
declare @output varchar(max)='', @return int, @sql varchar(max) = '', @list varchar(max) = '', @exec nvarchar(max), @Cols varchar(max)='',
@sCols varchar(max)='', @aCols varchar(max)='', @pCols varchar(max)='', @uCols varchar(max)='',
@b char(1) = char(13), @t char(1) = char(9);
select @exec = isnull(@exec + '+' + @b,'') + ''','' +' +
case
when c.data_type in ('uniqueidentifier')
then @t + '''''+isnull('''''''' + convert(varchar(50),' + c.column_name + ') + '''''''',''null'')'
when c.data_type in ('xml')
then @t + '''''+isnull('''''''' + convert(varchar(max),' + c.column_name + ') + '''''''',''null'')'
when c.data_type in ('char', 'nchar', 'varchar', 'nvarchar', 'sysname')
then @t + '''''+isnull('''''''' + replace(' + c.column_name + ','''''''','''''''''''') + '''''''',''null'')'
when c.data_type in ('datetime', 'date')
then @t + '''''+isnull('''''''' + convert(varchar,' + c.column_name + ',121)+'''''''',''null'') '
when c.data_type in ('tinyint', 'int', 'float', 'numeric', 'decimal', 'smallmoney', 'money', 'bit', 'smallint', 'real', 'bigint')
then @t + '''''+isnull(convert(varchar,' + c.column_name + '),''null'')'
else ''' ** data type [' + c.data_type + '] not supported **'''
end,
@Cols = @Cols + ','+quotename(c.column_name, '['),
@sCols = @sCols + ',s.'+quotename(c.column_name, '[')
from information_schema.columns c
where c.table_name = parsename(@TableName, 1) and
c.table_schema = parsename(@TableName, 2)
order
by c.ordinal_position
-- stage primary key columns
declare @pks table (c varchar(100), o int);
insert into @pks (c,o)
select kcu.column_name, kcu.ordinal_position
from information_schema.table_constraints tc
join information_schema.key_column_usage kcu on
tc.table_name = kcu.table_name and
tc.constraint_name = kcu.constraint_name
where tc.table_name = parsename(@TableName, 1) and
tc.table_schema = parsename(@TableName, 2) and
tc.constraint_type = 'PRIMARY KEY';
-- build primary key columns (1=1 to ease support of composite PKs)
set @pCols = '1=1'
select @pCols = @pCols + ' and '+isnull('t.'+quotename(c, '[') + ' = ' + 's.'+quotename(c, '['), '')
from @pks
order
by o;
-- build update columns, do not update identities or pks
select @aCols = @aCols + ','+quotename(c.[name], '[') + ' = s.' + quotename(c.[name], '[')
from sys.columns c
where object_id = object_id(@TableName) and
[name] not in (select c from @pks) and
columnproperty(object_id(@TableName), c.[name], 'IsIdentity ') = 0;
-- script the data out as table value constructors
select @exec = 'set nocount on; Select ' + @b + '''(' + ''' + ' + @b + stuff(@exec,1, 3, '') + '+'')''' + @b + 'from ' + @TableName,
@Cols = stuff(@Cols,1, 1, ''),
@sCols = stuff(@sCols,1, 1, ''),
@aCols = stuff(@aCols,1, 1, '');
declare @tab table (val varchar(max));
declare @Values varchar(max);
insert into @tab
exec(@exec);
if not exists(select 1 from @tab)
begin
raiserror('Table %s is valid but empty. Populate it before running this helper.', 16, 1, @TableName);
return
end
select @Values = stuff(cast((select ','+ @b + val from @tab for xml path('')) as xml).value('.', 'varchar(max)'),1,2,'');
-- build the merge statement
set @output += @b+'--'+@TableName+replicate('-', 98-len(@TableName))+@b+replicate('-', 100)+@b;
set @output += 'set nocount on;'+@b
if objectproperty(object_id(@TableName), 'TableHasIdentity') = 1
set @output += 'set identity_insert ['+parsename(@TableName, 2)+'].[' + parsename(@TableName, 1) + '] on;'+@b;
set @output += ';with cte_data('+@Cols+')'+@b+'as (select * from (values'+@b+'--'+replicate('/', 98) + @b +@Values+ @b +'--'+replicate('\', 98)+ @b +')c('+@Cols+'))'+@b;
set @output += 'merge' + @t + '['+parsename(@TableName, 2)+'].[' + parsename(@TableName, 1) + '] as t' + @b + 'using' + @t + 'cte_data as s'+@b;
set @output += 'on' + replicate(@t, 2) + @pCols+@b;
set @output += 'when matched then' + @b+@t + 'update set'+ @b+@t + @aCols+@b;
set @output += 'when not matched by target then'+@b;
set @output += @t+'insert(' + @Cols + ')'+@b;
set @output += @t+'values(' + @sCols + ')'+@b;
set @output += 'when not matched by source then' + @b+@t+ 'delete;'+@b;
if objectproperty(object_id(@TableName), 'TableHasIdentity') = 1
set @output += 'set identity_insert ['+parsename(@TableName, 2)+'].[' + parsename(@TableName, 1) + '] off;'
--output the statement as xml (to overcome mgmt studio limitations)
select s as [output] from (select @output)d(s) for xml path('');
return;