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Generate MERGE Statement for a Table (more info: https://eitanblumin.com/2018/10/28/generate-merge-statement-as-a-snapshot-of-your-tables-content/ )
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/* | |
=================================================== | |
Generate MERGE Statements for All Tables | |
=================================================== | |
Copyright: Eitan Blumin (C) 2012 | |
Email: [email protected] | |
Source: www.madeiradata.com | |
Disclaimer: | |
The author is not responsible for any damage this | |
script or any of its variations may cause. | |
Do not execute it or any variations of it on production | |
environments without first verifying its validity | |
on controlled testing and/or QA environments. | |
You may use this script at your own risk and may change it | |
to your liking, as long as you leave this disclaimer header | |
fully intact and unchanged. | |
Description: | |
This script finds all the tables in the database (only such with a primary key) | |
and generates a .sql file for each table, which contains a MERGE statement | |
using all the records currently present in the table. | |
Upon execution of these generated scripts, they will "initialize" the table | |
to only contain the records that were present at the time of the script generation. | |
Instructions: | |
There's no need to change anything except the values in | |
the Configuration Area at the beginning of this script. | |
Any other changes could change the behaviour of this script | |
and will be done at your own risk. | |
In any case, this script is commented as much as possible | |
to help you understand how it works. | |
Known Issues: | |
Due to the use of MERGE statements and VALUES constructor, these scripts will only | |
work in SQL Server version 2008 or higher. | |
If a MERGE statement is executed for a table which tries to delete rows, and these rows | |
are referenced by another table using a foreign key WITHOUT ON DELETE CASCADE, | |
then the execution will fail. For these scripts to work properly, all foreign keys | |
must have ON DELETE CASCADE turned on. | |
If at the time of the MERGE script generation, any tables have no rows, | |
The script file contents for them will be a single DELETE statement which deletes all records. | |
Columns with the IMAGE data type may cause conversion errors. | |
*/ | |
---------------- Start of Configuration Area ---------------- | |
DECLARE | |
-- Target path where to save your .sql files (must be ended with a slash \): | |
@OutputFolderPath NVARCHAR(4000) = N'C:\Temp\Output\', | |
-- BCP template for executing the MERGE statement generation procedure: | |
-- Change this to connect to the desired server using a working username and password (or use -T for trusted connection) | |
-- For more information on BCP please visit: http://msdn.microsoft.com/en-us/library/ms162802.aspx | |
/* This "template" uses placeholders for several changing variables (later replaced with values using REPLACE). | |
Each of these placeholders must not be removed or changed from this template: | |
{CurrTable} | |
{CurrSchema} | |
{FileName} | |
*/ | |
@BCPTemplate NVARCHAR(4000) = N'bcp "EXEC EitanTest.dbo.usp_Generate_Merge_For_Table ''{CurrTable}'', ''{CurrSchema}''" queryout "{FileName}" -c -T -S .' | |
---------------- End of Configuration Area ---------------- | |
-------- Changes below this line are at your own risk -------- | |
SET NOCOUNT ON; | |
-- Variable declaration | |
DECLARE | |
@CurrSchema SYSNAME, | |
@CurrTable SYSNAME, | |
@CurrMergeStmnt NVARCHAR(MAX), | |
@FileName NVARCHAR(4000), | |
@CMD NVARCHAR(4000) | |
-- Initialization of a cursor to traverse all the tables in the database | |
-- The tables are selected using a hierarchical query to conform with correct order | |
-- that the data should be inserted due to foreign key constraints. | |
-- (parent table will be generated before child table) | |
DECLARE ProcessTables CURSOR FOR | |
WITH reftree | |
AS | |
( | |
SELECT | |
ObjectId = ReferencingTables.object_id , | |
SchemaName = OBJECT_SCHEMA_NAME(ReferencingTables.object_id) , | |
TableName = ReferencingTables.name , | |
Depth = 1 | |
FROM | |
sys.tables AS ReferencingTables | |
LEFT OUTER JOIN | |
sys.foreign_keys AS ForeignKeys | |
ON | |
ReferencingTables.object_id = ForeignKeys.parent_object_id | |
AND | |
ReferencingTables.object_id != ForeignKeys.referenced_object_id | |
WHERE | |
ForeignKeys.object_id IS NULL | |
AND | |
ReferencingTables.is_ms_shipped = 0 | |
-- Only get tables with a primary key | |
AND EXISTS ( | |
SELECT NULL | |
FROM sys.indexes AS ind | |
WHERE | |
ind.object_id = ReferencingTables.object_id | |
AND ind.is_primary_key = 1 | |
) | |
UNION ALL | |
SELECT | |
ObjectId = ReferencingTables.object_id , | |
SchemaName = OBJECT_SCHEMA_NAME(ReferencingTables.object_id) , | |
TableName = ReferencingTables.name , | |
Depth = TableHierarchy.Depth + 1 | |
FROM | |
sys.tables AS ReferencingTables | |
INNER JOIN | |
sys.foreign_keys AS ForeignKeys | |
ON | |
ReferencingTables.object_id = ForeignKeys.parent_object_id | |
AND | |
ReferencingTables.object_id != ForeignKeys.referenced_object_id | |
INNER JOIN | |
reftree AS TableHierarchy | |
ON | |
ForeignKeys.referenced_object_id = TableHierarchy.ObjectId | |
WHERE | |
-- Only get tables with a primary key | |
EXISTS ( | |
SELECT NULL | |
FROM sys.indexes AS ind | |
WHERE | |
ind.object_id = ReferencingTables.object_id | |
AND ind.is_primary_key = 1 | |
) | |
) | |
SELECT | |
SchemaName, TableName | |
FROM reftree | |
GROUP BY | |
ObjectId, SchemaName, TableName | |
ORDER BY | |
MAX(Depth) ASC | |
; | |
-- Open cursor | |
OPEN ProcessTables | |
-- Fetch first row from cursor | |
FETCH NEXT FROM ProcessTables INTO @CurrSchema, @CurrTable | |
-- While a row is returned from the cursor | |
WHILE @@FETCH_STATUS = 0 | |
BEGIN | |
-- Display a message with the current table name | |
PRINT '' | |
RAISERROR(N'-------------- %s --------------', 0, 1, @CurrTable) WITH NOWAIT; | |
PRINT '' | |
-- Initialize full file path based on table and schema names | |
SET @FileName = @OutputFolderPath + @CurrSchema + '.' + @CurrTable + '.sql' | |
-- Replace placeholders with current settings | |
SET @CMD = REPLACE(@BCPTemplate, '{CurrTable}',REPLACE(@CurrTable,'''','''''')) | |
SET @CMD = REPLACE(@CMD, '{CurrSchema}', REPLACE(@CurrSchema,'''','''''')) | |
SET @CMD = REPLACE(@CMD, '{FileName}', @FileName) | |
PRINT 'Saving to ' + @FileName | |
PRINT @CMD | |
DECLARE @Output AS TABLE(Msg NVARCHAR(MAX)); | |
DECLARE @Msg NVARCHAR(MAX); | |
-- Execute the BCP command using CMDSHELL and save output in a variable table | |
INSERT INTO @Output | |
EXEC xp_cmdshell @CMD | |
-- Concatenate the output from the table into a string variable and print it | |
SELECT | |
-- This will concatenate all messages with a new line (char(10)) between them. | |
@Msg = ISNULL(@Msg + CHAR(10),'') + Msg | |
FROM | |
@Output | |
WHERE | |
Msg IS NOT NULL | |
RAISERROR(@Msg,0,1) WITH NOWAIT; | |
-- Reset output table and variable | |
DELETE @Output; | |
SET @Msg = NULL; | |
-- Fetch the next row from cursor | |
FETCH NEXT FROM ProcessTables INTO @CurrSchema, @CurrTable | |
END | |
-- Close and destroy the cursor object | |
CLOSE ProcessTables | |
DEALLOCATE ProcessTables |
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/* | |
=================================================== | |
Generate MERGE Statement for a Table | |
=================================================== | |
Copyright: Eitan Blumin (C) 2012 | |
Email: [email protected] | |
Source: www.madeiradata.com | |
Disclaimer: | |
The author is not responsible for any damage this | |
script or any of its variations may cause. | |
Do not execute it or any variations of it on production | |
environments without first verifying its validity | |
on controlled testing and/or QA environments. | |
You may use this script at your own risk and may change it | |
to your liking, as long as you leave this disclaimer header | |
fully intact and unchanged. | |
Description: | |
This procedure generates a MERGE statement for the table provided as a parameter, | |
using the records currently in the table. | |
The MERGE statement is returned in a query as a single row and column. | |
If there are no rows in the table, a simple DELETE statement will be generated instead. | |
Instructions: | |
The resulting script from this procedure can be used to "initialize" or "reset" | |
the desired table to the state it was in during the script generation. | |
For example: You're about to perform tests on your table and you wish to have | |
a "starting point" to which you can reset the table at any time. | |
Before starting your tests, you run this procedure to generate the initialization | |
script for the table and save it somewhere. You do your tests, and at any time | |
you can execute the script you saved to reset the table back to its state | |
at the beginning of the tests (of course, strictly in terms of data - not structure). | |
Important Note: | |
Tables that don't have a primary key are not supported! | |
*/ | |
IF OBJECT_ID('usp_Generate_Merge_For_Table', 'P') IS NOT NULL | |
BEGIN | |
PRINT 'Dropping existing procedure...' | |
DROP PROCEDURE usp_Generate_Merge_For_Table | |
END | |
PRINT 'Creating procedure...' | |
GO | |
/* | |
Sample usage: | |
EXEC usp_Generate_Merge_For_Table 'tbl_forms', 'dbo' | |
*/ | |
CREATE PROCEDURE [dbo].[usp_Generate_Merge_For_Table] | |
@CurrTable SYSNAME, -- table name | |
@CurrSchema SYSNAME = 'dbo', -- table schema name | |
@delete_unmatched_rows BIT = 1, -- enable/disable DELETION of rows | |
@update_existing_rows BIT = 1, -- enable/disable UPDATE of rows | |
@insert_new_rows BIT = 1, -- enable/disable INSERT of rows | |
@debug_mode BIT = 0, -- enable/disable debug mode | |
@include_timestamp BIT = 0, -- include timestamp columns or not | |
@ommit_computed_cols BIT = 1, -- ommit computed columns or not (in case target table doesn't have computed columns) | |
@top_clause NVARCHAR(4000) = N'TOP 100 PERCENT' -- you can use this to limit number of generate rows (e.g. TOP 200) | |
AS | |
SET NOCOUNT ON; | |
-- Variable declaration | |
DECLARE | |
@MergeStmnt NVARCHAR(MAX), | |
@CurrColumnId INT, | |
@CurrColumnName SYSNAME, | |
@CurrColumnType VARCHAR(1000), | |
@ColumnList NVARCHAR(MAX), | |
@UpdateSet NVARCHAR(MAX), | |
@PKJoinClause NVARCHAR(MAX), | |
@HasIdentity BIT, | |
@GetValues NVARCHAR(MAX), | |
@Values NVARCHAR(MAX) | |
-- Init variables | |
SELECT | |
@CurrColumnId = NULL, | |
@CurrColumnName = NULL, | |
@CurrColumnType = NULL, | |
@MergeStmnt = NULL, | |
@ColumnList = NULL, | |
@UpdateSet = NULL, | |
@PKJoinClause = NULL, | |
@GetValues = NULL, | |
@Values = NULL, | |
@HasIdentity = 0 | |
-- Make sure table exists | |
IF OBJECT_ID(QUOTENAME(@CurrSchema) + '.' + QUOTENAME(@CurrTable)) IS NULL | |
BEGIN | |
RAISERROR(N'ERROR: Table [%s].[%s] not found.', 16, 1, @CurrSchema, @CurrTable) WITH NOWAIT; | |
GOTO Quit; | |
END | |
-- find the table's Primary Key column(s) to build a JOIN clause | |
SELECT | |
@PKJoinClause = ISNULL(@PKJoinClause + N' | |
AND ',N'') + 'trgt.' + QUOTENAME(col.name) + N' = src.' + QUOTENAME(col.name) | |
FROM | |
sys.indexes AS ind | |
INNER JOIN | |
sys.index_columns AS indcol | |
ON | |
ind.object_id = indcol.object_id | |
AND ind.index_id = indcol.index_id | |
INNER JOIN | |
sys.columns AS col | |
ON | |
ind.object_id = col.object_id | |
AND indcol.column_id = col.column_id | |
WHERE | |
ind.is_primary_key = 1 | |
AND ind.object_id = OBJECT_ID(QUOTENAME(@CurrSchema) + '.' + QUOTENAME(@CurrTable)) | |
IF @debug_mode = 1 | |
PRINT 'PK Join Clause: | |
' + @PKJoinClause | |
-- If nothing found, abort (table is not supported) | |
IF @PKJoinClause IS NULL | |
BEGIN | |
RAISERROR(N'ERROR: Table %s is not supported because it''s missing a Primary Key.', 16, 1, @CurrTable) WITH NOWAIT; | |
GOTO Quit; | |
END | |
-- start with the first column | |
SELECT | |
@CurrColumnId = MIN(ORDINAL_POSITION) | |
FROM | |
INFORMATION_SCHEMA.COLUMNS WITH (NOLOCK) | |
WHERE | |
TABLE_NAME = @CurrTable | |
AND TABLE_SCHEMA = @CurrSchema | |
-- loop through all the table columns, to get the column names and their data types | |
WHILE @CurrColumnId IS NOT NULL | |
BEGIN | |
SELECT | |
@CurrColumnName = QUOTENAME(COLUMN_NAME), | |
@CurrColumnType = DATA_TYPE | |
FROM | |
INFORMATION_SCHEMA.COLUMNS WITH (NOLOCK) | |
WHERE | |
ORDINAL_POSITION = @CurrColumnId | |
AND TABLE_NAME = @CurrTable | |
AND TABLE_SCHEMA = @CurrSchema | |
IF @debug_mode = 1 | |
PRINT 'Processing column ' + @CurrColumnName | |
-- Choosing whether to output computed columns or not | |
IF @ommit_computed_cols = 1 | |
BEGIN | |
IF (SELECT COLUMNPROPERTY( OBJECT_ID(QUOTENAME(@CurrSchema) + '.' + @CurrTable),SUBSTRING(@CurrColumnName,2,LEN(@CurrColumnName) - 2),'IsComputed')) = 1 | |
BEGIN | |
GOTO SKIP_COLUMN | |
END | |
END | |
-- Concatenate column value selection to the values list | |
SET @GetValues = ISNULL( @GetValues + ' + '',''' , '''(''' ) + ' + ' + | |
CASE | |
-- Format column value retrieval based on its data type | |
WHEN @CurrColumnType IN ('text','char','varchar','time') | |
THEN | |
'COALESCE('''''''' + REPLACE(CONVERT(nvarchar(max),' + @CurrColumnName + '),'''''''','''''''''''')+'''''''',''NULL'')' | |
WHEN @CurrColumnType IN ('ntext','nchar','nvarchar','xml') | |
THEN | |
'COALESCE(''N'''''' + REPLACE(CONVERT(nvarchar(max),' + @CurrColumnName + '),'''''''','''''''''''')+'''''''',''NULL'')' | |
WHEN @CurrColumnType LIKE '%date%' | |
THEN | |
'COALESCE('''''''' + RTRIM(CONVERT(varchar(max),' + @CurrColumnName + ',109))+'''''''',''NULL'')' | |
WHEN @CurrColumnType IN ('uniqueidentifier') | |
THEN | |
'COALESCE('''''''' + REPLACE(CONVERT(varchar(255),RTRIM(' + @CurrColumnName + ')),'''''''','''''''''''')+'''''''',''NULL'')' | |
WHEN @CurrColumnType IN ('binary','varbinary','image') | |
THEN | |
'COALESCE(RTRIM(CONVERT(nvarchar(max),' + @CurrColumnName + ',1)),''NULL'')' | |
WHEN @CurrColumnType IN ('timestamp','rowversion') | |
THEN | |
CASE | |
WHEN @include_timestamp = 0 | |
THEN | |
'''DEFAULT''' | |
ELSE | |
'COALESCE(RTRIM(CONVERT(varchar(max),' + 'CONVERT(int,' + @CurrColumnName + '))),''NULL'')' | |
END | |
WHEN @CurrColumnType IN ('float','real','money','smallmoney') | |
THEN | |
'COALESCE(LTRIM(RTRIM(' + 'CONVERT(varchar(max), ' + @CurrColumnName + ',2)' + ')),''NULL'')' | |
ELSE | |
'COALESCE(LTRIM(RTRIM(' + 'CONVERT(varchar(max), ' + @CurrColumnName + ')' + ')),''NULL'')' | |
END | |
-- Concatenate column name to column list | |
SET @ColumnList = ISNULL(@ColumnList + N',',N'') + @CurrColumnName | |
-- Make sure to output SET IDENTITY_INSERT ON/OFF in case the table has an IDENTITY column | |
IF (SELECT COLUMNPROPERTY( OBJECT_ID(QUOTENAME(@CurrSchema) + '.' + @CurrTable),SUBSTRING(@CurrColumnName,2,LEN(@CurrColumnName) - 2),'IsIdentity')) = 1 | |
BEGIN | |
SET @HasIdentity = 1 | |
END | |
ELSE IF NOT EXISTS | |
( | |
SELECT | |
NULL | |
FROM | |
sys.indexes AS ind | |
INNER JOIN | |
sys.index_columns AS indcol | |
ON | |
ind.object_id = indcol.object_id | |
AND ind.index_id = indcol.index_id | |
WHERE | |
ind.is_primary_key = 1 | |
AND ind.object_id = OBJECT_ID(QUOTENAME(@CurrSchema) + '.' + QUOTENAME(@CurrTable)) | |
AND indcol.column_id = @CurrColumnId | |
) | |
BEGIN | |
-- If column is not IDENTITY and not part of the PK, then concatenate it to UPDATE SET clause | |
SET @UpdateSet = ISNULL(@UpdateSet + N' | |
, ', N'') + @CurrColumnName + N' = src.' + @CurrColumnName | |
END | |
SKIP_COLUMN: -- The label used in GOTO to skip column | |
-- Get next column in order | |
SELECT | |
@CurrColumnId = MIN(ORDINAL_POSITION) | |
FROM | |
INFORMATION_SCHEMA.COLUMNS WITH (NOLOCK) | |
WHERE | |
ORDINAL_POSITION > @CurrColumnId | |
AND TABLE_NAME = @CurrTable | |
AND TABLE_SCHEMA = @CurrSchema | |
-- Column loop ends here | |
END | |
-- Finalize VALUES constructor | |
SET @GetValues = @GetValues + ' + '')'' '; | |
IF @debug_mode = 1 | |
PRINT 'Values Retrieval: | |
' + @GetValues + ' | |
'; | |
-- Using everything we found above, save all the table records as a values constructor (using dynamic SQL) | |
DECLARE @Params NVARCHAR(MAX) | |
DECLARE @CMD NVARCHAR(MAX); | |
SET @Params = N'@Result NVARCHAR(MAX) OUTPUT' | |
SET @CMD = 'SELECT ' + @top_clause + N' | |
@Result = ISNULL(@Result + '', | |
'','''') + ' + @GetValues + ' FROM ' + QUOTENAME(@CurrSchema) + '.' + QUOTENAME(@CurrTable) | |
IF @debug_mode = 1 | |
SELECT @CMD; | |
-- Execute command and get the @Values parameter as output | |
EXECUTE sp_executesql @CMD, @Params, @Values OUTPUT | |
-- If table returned no rows, then there's nothing to output other than deletion command | |
IF @@ROWCOUNT = 0 OR @Values IS NULL | |
BEGIN | |
-- If deletion is enabled | |
IF @delete_unmatched_rows = 1 | |
-- Generate a simple DELETE statement | |
SET @MergeStmnt = N'DELETE FROM ' + QUOTENAME(@CurrSchema) + N'.' + QUOTENAME(@CurrTable) | |
ELSE | |
-- Otherwise, generate an empty script | |
SET @MergeStmnt = N'' | |
END | |
ELSE | |
-- Otherwise, build the MERGE statement | |
BEGIN | |
-- Use IDENTITY_INSERT if table has an identity column | |
IF @HasIdentity = 1 | |
SET @MergeStmnt = 'SET IDENTITY_INSERT ' + QUOTENAME(@CurrSchema) + '.' + QUOTENAME(@CurrTable) + ' ON;' | |
ELSE | |
SET @MergeStmnt = N'' | |
-- Build the MERGE statement using all the parts we found | |
SET @MergeStmnt = @MergeStmnt + N' | |
MERGE INTO ' + QUOTENAME(@CurrSchema) + N'.' + QUOTENAME(@CurrTable) + N' AS trgt | |
USING (VALUES | |
' + @Values + N' | |
) AS src(' + @ColumnList + N') | |
ON | |
' + @PKJoinClause | |
+ CASE WHEN @update_existing_rows = 1 THEN N' | |
WHEN MATCHED THEN | |
UPDATE SET | |
' + @UpdateSet | |
ELSE N'' END | |
+ CASE WHEN @insert_new_rows = 1 THEN N' | |
WHEN NOT MATCHED BY TARGET THEN | |
INSERT (' + @ColumnList + N') | |
VALUES (' + @ColumnList + N')' | |
ELSE N'' END | |
+ CASE WHEN @delete_unmatched_rows = 1 THEN N' | |
WHEN NOT MATCHED BY SOURCE THEN | |
DELETE' | |
ELSE N'' END + N' | |
; | |
'; | |
-- Use IDENTITY_INSERT if table has an identity column | |
IF @HasIdentity = 1 | |
SET @MergeStmnt = @MergeStmnt + 'SET IDENTITY_INSERT ' + QUOTENAME(@CurrSchema) + '.' + QUOTENAME(@CurrTable) + ' OFF;' | |
END | |
Quit: | |
-- Output the final statement | |
-- Print long text | |
DECLARE | |
@CurrStart int, | |
@TotalLen int, | |
@CurrID int, | |
@CurrMsg nvarchar(max) | |
SELECT | |
@CurrStart = 1, | |
@TotalLen = LEN(@MergeStmnt); | |
WHILE @CurrStart < @TotalLen | |
BEGIN | |
-- Find next linebreak | |
SET @CurrID = CHARINDEX(CHAR(10),@MergeStmnt,@CurrStart) | |
-- If linebreak found | |
IF @CurrID > 0 | |
BEGIN | |
-- Trim line from message, print it and increase index | |
SET @CurrMsg = SUBSTRING(@MergeStmnt,@CurrStart,@CurrID-@CurrStart-1) | |
PRINT @CurrMsg | |
SET @CurrStart = @CurrID + 1 | |
END | |
ELSE | |
BEGIN | |
-- Print last line | |
SET @CurrMsg = SUBSTRING(@MergeStmnt,@CurrStart,@TotalLen) | |
PRINT @CurrMsg | |
SET @CurrStart = @TotalLen | |
END | |
END | |
SELECT @MergeStmnt AS Command; |
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This works perfectly and it saved me a lot of time. Thanks very much.