Did you encountered a problem where you wanted to change your database collation to default or even just changing it to a different type? I guess what you had initially done (like me) was to change the collation of the Database
well that does not quite work well as the existing columns will not be changed and retain its current collation type, only the newly created objects will use this new collation type. So you are left to the option of changing the columns one at a time by going to the column property and restoring it to default or choosing the collation type you want.
Well that’s great if you need to change 10 columns or less but what if you want to change the whole database? What if it’s a primary key or a foreign key? Well isn’t that a nightmare? Well I will give you an easy solution and all you need to do is to run 6 easy steps. If you don’t want to recreate the database and pump data by using DTS or SSIS then this is the solution for you just make sure backup and restore everything before doing any changes.
Step 1: Prepare your DB and Change the collation to your desired one.
Like I had said backup your database as a part of the preparation, once that’s done change your collation to the desired type by going to the database properties by right clicking on the database and choosing properties, once your on the properties window choose options and you can see the collation from there, choose what you want then hit OK. This will ensure that new objects created will be using the new collation.
Step 2: Create you Change Collation Script.
Next is to create a script to change the collation of every object in your database. You need to use the information_schema to extract columns needed to be changed and from there we run a loop on all objects creating alter scripts on each item. Since it is a collation change we will only need fields that uses character types and text types. What you need is to have a lot of commands similar to this
ALTER TABLE TABLENAME ALTER COLUMN COLUMNNAME varchar(100) COLLATE Latin1_General_CI_AS NULL
So here is the code to generate that
OPEN MyTableCursor
FETCH NEXT FROM MyTableCursor INTO @TableName
WHILE @@FETCH_STATUS = 0
BEGIN
DECLARE MyColumnCursor Cursor
FOR
SELECT COLUMN_NAME,DATA_TYPE, CHARACTER_MAXIMUM_LENGTH,IS_NULLABLE from information_schema.columns
WHERE table_name = @TableName AND (Data_Type LIKE '%char%' OR Data_Type LIKE '%text%') AND COLLATION_NAME <> @CollationName
ORDER BY ordinal_position
Open MyColumnCursor
FETCH NEXT FROM MyColumnCursor INTO @ColumnName, @DataType, @CharacterMaxLen, @IsNullable
WHILE @@FETCH_STATUS = 0
BEGIN
SET @SQLText = 'ALTER TABLE ' + @TableName + ' ALTER COLUMN [' + @ColumnName + '] ' + @DataType + '(' + CASE WHEN @CharacterMaxLen = -1 THEN 'MAX' ELSE @CharacterMaxLen END + ') COLLATE ' + @CollationName + ' ' + CASE WHEN @IsNullable = 'NO' THEN 'NOT NULL' ELSE 'NULL' END
PRINT @SQLText
FETCH NEXT FROM MyColumnCursor INTO @ColumnName, @DataType, @CharacterMaxLen, @IsNullable
END
CLOSE MyColumnCursor
DEALLOCATE MyColumnCursor
FETCH NEXT FROM MyTableCursor INTO @TableName
END
CLOSE MyTableCursor
DEALLOCATE MyTableCursor
Run it then save the script for later use. Lets call the script “ChangeCollation.sql”
If you don’t have relationships, primary keys and foreign keys then you don’t need to do the next step.
Step 3: Create a Stored Procedure to Script Indexes and Relationships
Well if you have relationships, primary keys and foreign keys then that’s a good practice but you need to script them as you need to drop those before changing the collation. Initially I thought I can do this with the wizard and choose to script indexes but it does not create on its own the table creation is always included so with a little help from Google I don’t have to write a single piece of code. I found this really good script to do it and I got it from here http://sqlblog.com/blogs/adam_machanic/archive/2010/04/04/rejuvinated-script-creates-and-drops-for-candidate-keys-and-referencing-foreign-keys.aspx
I only separated the Create Indexes and Drop Indexes as we need to run a process in the middle.
Here is the Create Index script courtesy of Adam Machanic
/*
Script Table Keys
(C) 2010 Adam Machanic - amachanic@gmail.com
http://sqlblog.com/blogs/adam_machanic/archive/2010/04/04/rejuvinated-script-creates-and-drops-for-candidate-keys-and-referencing-foreign-keys.aspx
This script produces a script of all of the candidate keys (primary keys or unique
constraints) as well as referencing foreign keys, for the target table. To use, put
SSMS into "results in text" mode and run the script. The output will be a formatted
script that you can cut and paste to use elsewhere.
Don't forget to configure the maximum text size before using. The default is 256
characters--not enough for many cases.
Tools->Options->Query Results->Results to Text->Maximum number of characters->8192
*/
CREATE PROC [dbo].[ScriptCreateTableKeys]
@table_name SYSNAME
AS
BEGIN
SET NOCOUNT ON
--Note: Disabled keys and constraints are ignored
--TODO: Drop and re-create referencing XML indexes, FTS catalogs
DECLARE @crlf CHAR(2)
SET @crlf = CHAR(13) + CHAR(10)
DECLARE @version CHAR(4)
SET @version = SUBSTRING(@@VERSION, LEN('Microsoft SQL Server') + 2, 4)
DECLARE @object_id INT
SET @object_id = OBJECT_ID(@table_name)
DECLARE @sql NVARCHAR(MAX)
IF @version NOT IN ('2005', '2008')
BEGIN
RAISERROR('This script only supports SQL Server 2005 and 2008', 16, 1)
RETURN
END
SET @sql = '' +
'SELECT ' +
'CASE ' +
'WHEN 1 IN (i.is_primary_key, i.is_unique_constraint) THEN ' +
'''ALTER TABLE '' + ' +
'QUOTENAME(OBJECT_SCHEMA_NAME(i.object_id)) + ''.'' + ' +
'QUOTENAME(OBJECT_NAME(i.object_id)) + @crlf + ' +
'''ADD '' + ' +
'CASE k.is_system_named ' +
'WHEN 0 THEN ''CONSTRAINT '' + QUOTENAME(k.name) + @crlf ' +
'ELSE '''' ' +
'END + ' +
'CASE k.type ' +
'WHEN ''UQ'' THEN ''UNIQUE'' ' +
'ELSE ''PRIMARY KEY'' ' +
'END + '' '' + ' +
'i.type_desc + @crlf + ' +
'kc.key_columns + @crlf ' +
'ELSE ' +
'''CREATE UNIQUE '' + i.type_desc + '' INDEX '' + ' +
'QUOTENAME(i.name) + @crlf + ' +
'''ON '' + ' +
'QUOTENAME(OBJECT_SCHEMA_NAME(i.object_id)) + ''.'' + ' +
'QUOTENAME(OBJECT_NAME(i.object_id)) + @crlf + ' +
'kc.key_columns + @crlf + ' +
'COALESCE ' +
'( ' +
'''INCLUDE '' + @crlf + ' +
'''( '' + @crlf + ' +
'STUFF ' +
'( ' +
'( ' +
'SELECT ' +
'( ' +
'SELECT ' +
''','' + @crlf + '' '' + QUOTENAME(c.name) AS [text()] ' +
'FROM sys.index_columns AS ic ' +
'JOIN sys.columns AS c ON ' +
'c.object_id = ic.object_id ' +
'AND c.column_id = ic.column_id ' +
'WHERE ' +
'ic.object_id = i.object_id ' +
'AND ic.index_id = i.index_id ' +
'AND ic.is_included_column = 1 ' +
'ORDER BY ' +
'ic.key_ordinal ' +
'FOR XML PATH(''''), TYPE ' +
').value(''.'', ''VARCHAR(MAX)'') ' +
'), ' +
'1, ' +
'3, ' +
''''' ' +
') + @crlf + ' +
''')'' + @crlf, ' +
''''' ' +
') ' +
'END + ' +
'''WITH '' + @crlf + ' +
'''('' + @crlf + ' +
''' PAD_INDEX = '' + ' +
'CASE CONVERT(VARCHAR, i.is_padded) ' +
'WHEN 1 THEN ''ON'' ' +
'ELSE ''OFF'' ' +
'END + '','' + @crlf + ' +
'CASE i.fill_factor ' +
'WHEN 0 THEN '''' ' +
'ELSE ' +
''' FILLFACTOR = '' + ' +
'CONVERT(VARCHAR, i.fill_factor) + '','' + @crlf ' +
'END + ' +
''' IGNORE_DUP_KEY = '' + ' +
'CASE CONVERT(VARCHAR, i.ignore_dup_key) ' +
'WHEN 1 THEN ''ON'' ' +
'ELSE ''OFF'' ' +
'END + '','' + @crlf + ' +
''' ALLOW_ROW_LOCKS = '' + ' +
'CASE CONVERT(VARCHAR, i.allow_row_locks) ' +
'WHEN 1 THEN ''ON'' ' +
'ELSE ''OFF'' ' +
'END + '','' + @crlf + ' +
''' ALLOW_PAGE_LOCKS = '' + ' +
'CASE CONVERT(VARCHAR, i.allow_page_locks) ' +
'WHEN 1 THEN ''ON'' ' +
'ELSE ''OFF'' ' +
'END + ' +
CASE @version
WHEN '2005' THEN ''
ELSE
''','' + @crlf + ' +
''' DATA_COMPRESSION = '' + ' +
'( ' +
'SELECT ' +
'CASE ' +
'WHEN MIN(p.data_compression_desc) = MAX(p.data_compression_desc) THEN MAX(p.data_compression_desc) ' +
'ELSE ''[PARTITIONS USE MULTIPLE COMPRESSION TYPES]'' ' +
'END ' +
'FROM sys.partitions AS p ' +
'WHERE ' +
'p.object_id = i.object_id ' +
'AND p.index_id = i.index_id ' +
') '
END + '+ @crlf + ' +
''') '' + @crlf + ' +
'''ON '' + ds.data_space + '';'' + ' +
'@crlf + @crlf COLLATE database_default AS [-- Create Candidate Keys] ' +
'FROM sys.indexes AS i ' +
'LEFT OUTER JOIN sys.key_constraints AS k ON ' +
'k.parent_object_id = i.object_id ' +
'AND k.unique_index_id = i.index_id ' +
'CROSS APPLY ' +
'( ' +
'SELECT ' +
'''( '' + @crlf + ' +
'STUFF ' +
'( ' +
'( ' +
'SELECT ' +
'( ' +
'SELECT ' +
''','' + @crlf + '' '' + QUOTENAME(c.name) AS [text()] ' +
'FROM sys.index_columns AS ic ' +
'JOIN sys.columns AS c ON ' +
'c.object_id = ic.object_id ' +
'AND c.column_id = ic.column_id ' +
'WHERE ' +
'ic.object_id = i.object_id ' +
'AND ic.index_id = i.index_id ' +
'AND ic.key_ordinal > 0 ' +
'ORDER BY ' +
'ic.key_ordinal ' +
'FOR XML PATH(''''), TYPE ' +
').value(''.'', ''VARCHAR(MAX)'') ' +
'), ' +
'1, ' +
'3, ' +
''''' ' +
') + @crlf + ' +
''')'' ' +
') AS kc (key_columns) ' +
'CROSS APPLY ' +
'( ' +
'SELECT ' +
'QUOTENAME(d.name) + ' +
'CASE d.type ' +
'WHEN ''PS'' THEN ' +
'+ ' +
'''('' + ' +
'( ' +
'SELECT ' +
'QUOTENAME(c.name) ' +
'FROM sys.index_columns AS ic ' +
'JOIN sys.columns AS c ON ' +
'c.object_id = ic.object_id ' +
'AND c.column_id = ic.column_id ' +
'WHERE ' +
'ic.object_id = i.object_id ' +
'AND ic.index_id = i.index_id ' +
'AND ic.partition_ordinal = 1 ' +
') + ' +
''')'' ' +
'ELSE '''' ' +
'END ' +
'FROM sys.data_spaces AS d ' +
'WHERE ' +
'd.data_space_id = i.data_space_id ' +
') AS ds (data_space) ' +
'WHERE ' +
'i.object_id = @object_id ' +
'AND i.is_unique = 1 ' +
--filtered and hypothetical indexes cannot be candidate keys
CASE @version
WHEN '2008' THEN 'AND i.has_filter = 0 '
ELSE ''
END +
'AND i.is_hypothetical = 0 ' +
'AND i.is_disabled = 0 ' +
'ORDER BY ' +
'i.index_id '
EXEC sp_executesql
@sql,
N'@object_id INT, @crlf CHAR(2)',
@object_id, @crlf
SELECT
'ALTER TABLE ' +
QUOTENAME(OBJECT_SCHEMA_NAME(fk.parent_object_id)) + '.' +
QUOTENAME(OBJECT_NAME(fk.parent_object_id)) + @crlf +
CASE fk.is_not_trusted
WHEN 0 THEN 'WITH CHECK '
ELSE 'WITH NOCHECK '
END +
'ADD ' +
CASE fk.is_system_named
WHEN 0 THEN 'CONSTRAINT ' + QUOTENAME(name) + @crlf
ELSE ''
END +
'FOREIGN KEY ' + @crlf +
'( ' + @crlf +
STUFF
(
(
SELECT
(
SELECT
',' + @crlf + ' ' + QUOTENAME(c.name) AS [text()]
FROM sys.foreign_key_columns AS fc
JOIN sys.columns AS c ON
c.object_id = fc.parent_object_id
AND c.column_id = fc.parent_column_id
WHERE
fc.constraint_object_id = fk.object_id
ORDER BY
fc.constraint_column_id
FOR XML PATH(''), TYPE
).value('.', 'VARCHAR(MAX)')
),
1,
3,
''
) + @crlf +
') ' +
'REFERENCES ' +
QUOTENAME(OBJECT_SCHEMA_NAME(fk.referenced_object_id)) + '.' +
QUOTENAME(OBJECT_NAME(fk.referenced_object_id)) + @crlf +
'( ' + @crlf +
STUFF
(
(
SELECT
(
SELECT
',' + @crlf + ' ' + QUOTENAME(c.name) AS [text()]
FROM sys.foreign_key_columns AS fc
JOIN sys.columns AS c ON
c.object_id = fc.referenced_object_id
AND c.column_id = fc.referenced_column_id
WHERE
fc.constraint_object_id = fk.object_id
ORDER BY
fc.constraint_column_id
FOR XML PATH(''), TYPE
).value('.', 'VARCHAR(MAX)')
),
1,
3,
''
) + @crlf +
');' +
@crlf + @crlf COLLATE database_default AS [-- Create Referencing FKs]
FROM sys.foreign_keys AS fk
WHERE
referenced_object_id = @object_id
AND is_disabled = 0
ORDER BY
key_index_id
END
Step 4: Create Stored Procedure to Script Drop Indexes and Relationships
Now you also need to create the drop scripts, these is the other half of Adam Machanic’s script
CREATE PROC [dbo].[ScriptDropTableKeys]
@table_name SYSNAME
AS
BEGIN
SET NOCOUNT ON
--Note: Disabled keys and constraints are ignored
--TODO: Drop and re-create referencing XML indexes, FTS catalogs
DECLARE @crlf CHAR(2)
SET @crlf = CHAR(13) + CHAR(10)
DECLARE @version CHAR(4)
SET @version = SUBSTRING(@@VERSION, LEN('Microsoft SQL Server') + 2, 4)
DECLARE @object_id INT
SET @object_id = OBJECT_ID(@table_name)
DECLARE @sql NVARCHAR(MAX)
IF @version NOT IN ('2005', '2008')
BEGIN
RAISERROR('This script only supports SQL Server 2005 and 2008', 16, 1)
RETURN
END
SELECT
'ALTER TABLE ' +
QUOTENAME(OBJECT_SCHEMA_NAME(parent_object_id)) + '.' +
QUOTENAME(OBJECT_NAME(parent_object_id)) + @crlf +
'DROP CONSTRAINT ' + QUOTENAME(name) + ';' +
@crlf + @crlf COLLATE database_default AS [-- Drop Referencing FKs]
FROM sys.foreign_keys
WHERE
referenced_object_id = @object_id
AND is_disabled = 0
ORDER BY
key_index_id DESC
SET @sql = '' +
'SELECT ' +
'statement AS [-- Drop Candidate Keys] ' +
'FROM ' +
'( ' +
'SELECT ' +
'CASE ' +
'WHEN 1 IN (i.is_unique_constraint, i.is_primary_key) THEN ' +
'''ALTER TABLE '' + ' +
'QUOTENAME(OBJECT_SCHEMA_NAME(i.object_id)) + ''.'' + ' +
'QUOTENAME(OBJECT_NAME(i.object_id)) + @crlf + ' +
'''DROP CONSTRAINT '' + QUOTENAME(i.name) + '';'' + ' +
'@crlf + @crlf COLLATE database_default ' +
'ELSE ' +
'''DROP INDEX '' + QUOTENAME(i.name) + @crlf + ' +
'''ON '' + ' +
'QUOTENAME(OBJECT_SCHEMA_NAME(object_id)) + ''.'' + ' +
'QUOTENAME(OBJECT_NAME(object_id)) + '';'' + ' +
'@crlf + @crlf COLLATE database_default ' +
'END AS statement, ' +
'i.index_id ' +
'FROM sys.indexes AS i ' +
'WHERE ' +
'i.object_id = @object_id ' +
'AND i.is_unique = 1 ' +
--filtered and hypothetical indexes cannot be candidate keys
CASE @version
WHEN '2008' THEN 'AND i.has_filter = 0 '
ELSE ''
END +
'AND i.is_hypothetical = 0 ' +
'AND i.is_disabled = 0 ' +
') AS x ' +
'ORDER BY ' +
'index_id DESC '
EXEC sp_executesql
@sql,
N'@object_id INT, @crlf CHAR(2)',
@object_id, @crlf
END
Step 5: Bringing them all together
Now you have the two stored procedure all you have to do is to loop though all tables in you database and pass that as the parameter of the Stored Procedure. First we use the ScriptCreateTableKeys.
DECLARE @TableName nvarchar(255)
DECLARE MyTableCursor Cursor
FOR
SELECT name FROM sys.tables WHERE [type] = 'U' and name <> 'sysdiagrams' ORDER BY name
OPEN MyTableCursor
FETCH NEXT FROM MyTableCursor INTO @TableName
WHILE @@FETCH_STATUS = 0
BEGIN
EXEC ScriptCreateTableKeys @TableName
FETCH NEXT FROM MyTableCursor INTO @TableName
END
CLOSE MyTableCursor
DEALLOCATE MyTableCursor
Then lets use the ScriptDropTableKeys
DECLARE @TableName nvarchar(255)
DECLARE MyTableCursor Cursor
FOR
SELECT name FROM sys.tables WHERE [type] = 'U' and name <> 'sysdiagrams' ORDER BY name
OPEN MyTableCursor
FETCH NEXT FROM MyTableCursor INTO @TableName
WHILE @@FETCH_STATUS = 0
BEGIN
EXEC ScriptDropTableKeys @TableName
FETCH NEXT FROM MyTableCursor INTO @TableName
END
CLOSE MyTableCursor
DEALLOCATE MyTableCursor
Just make sure when you execute them output the results as text so you can easily copy and paste the results.
Save the first results as “CreateKeysAndIndexes.sql” and the second as “DropKeysAndIndexes.sql”
Step 6: Run you saved scripts
In this order run your scripts and wait for the results, time wait might vary depending on your database size.
a. DropKeysAndIndexes.sql
b. ChangeCollation.sql
c. CreateKeysAndIndexes.sql
