I'm stuck with a problem in MariaDb 10.6.4, which I didn't encounter in 10.5.12.
I set the default character set and default collation for my database (and actually for my server) to utf8mb4 and utf8mb4_general_ci.
Though the server setting doesn't affect the defaults for information_schema, performance_schema and sys in 10.6.4 (they are still utf8mb3), all other databases which I create having utf8mb4.
I use SELECT SCHEMA_NAME, DEFAULT_CHARACTER_SET_NAME, DEFAULT_COLLATION_NAME FROM information_schema.SCHEMATA to verify the default settings.
I use the following Sql to create a test table on the database ETLBox_DataFlow2
CREATE TABLE testtable
(
col1 NVARCHAR(100) NULL,
col2 VARCHAR(100) NULL,
col3 VARCHAR(100) COLLATE 'utf8mb4_general_ci',
col4 VARCHAR(100) CHARACTER SET 'utf8mb4'
)
When I check the character set & collation that each column uses, I see that the NVARCHAR column still has utf8mb3 as default character set.
SELECT COLUMN_NAME, CHARACTER_SET_NAME, COLLATION_NAME
FROM information_schema.Columns
WHERE TABLE_NAME = 'testtable'
This is very unfortunate, as I use C# and the latest MySql connector 8.0 to retrieve data from this table. But the connector won't work with data collated in utf8mb3, as this is already deprecated by MySql/Oracle.
I never had this issue with MariaDb 10.5.12. I know that MariaDb changed the default for utf8, but I thought that now everything would be aligned to utf8mb4 to be in line with MySql. I tried to play around with the ##OLD_MODE, but didn't see any differences here when creating the table.
Is there a way to change this behaviour? I would like that also NVARCHAR columns are collated to utf8mb4 by default (or actually any other collation than utf8mb3 would work for me).
Looking forward to your replies!
I've searched high and low but can't find an answer, can you set the collation of a variable? According to the MS documentation, it seems that it's only possible on SQL Azure:
-- Syntax for Azure SQL Data Warehouse and Parallel Data Warehouse
DECLARE
{{ #local_variable [AS] data_type } [ =value [ COLLATE ] ] } [,...n]
Currently I have to do this:
DECLARE #Test nvarchar(10) = N'Crud';
IF ( #Test = N'Crud' COLLATE Latin1_General_CS_AI )
Print N'Crud';
IF ( #Test = N'cRud' COLLATE Latin1_General_CS_AI )
Print N'cRud';
IF ( #Test = N'crUd' COLLATE Latin1_General_CS_AI )
Print N'crUd';
IF ( #Test = N'cruD' COLLATE Latin1_General_CS_AI )
Print N'cruD';
When what I'd like to do is this:
DECLARE #Test nvarchar(10) = N'Crud' COLLATE Latin1_General_CS_AI;
IF ( #Test = N'Crud' )
Print N'Crud';
IF ( #Test = N'cRud' )
Print N'cRud';
IF ( #Test = N'crUd' )
Print N'crUd';
IF ( #Test = N'cruD' )
Print N'cruD';
I'm guessing the answer is no but I wanted to confirm and at the very least, someone else ever needing this info will get a definitive answer.
Much appreciated.
Well, you're guessing correctly.
In most SQL Server systems, (meaning, not including Azure SQL Data Warehouse and Parallel Data Warehouse) A collation can be set on four levels:
The default collation of the SQL Server instance:
The server collation acts as the default collation for all system databases that are installed with the instance of SQL Server, and also any newly created user databases.
The default collation of a specific database:
You can use the COLLATE clause of the CREATE DATABASE or ALTER DATABASE statement to specify the default collation of the database. You can also specify a collation when you create a database using SQL Server Management Studio. If you do not specify a collation, the database is assigned the default collation of the instance of SQL Server.
You can set a collation for a table's column:
You can specify collations for each character string column using the COLLATE clause of the CREATE TABLE or ALTER TABLE statement. You can also specify a collation when you create a table using SQL Server Management Studio. If you do not specify a collation, the column is assigned the default collation of the database.
You can set a collation for a specific expression using the Collate clause:
You can use the COLLATE clause to apply a character expression to a certain collation. Character literals and variables are assigned the default collation of the current database. Column references are assigned the definition collation of the column.
So yes, with the exception of Azure SQL Data Warehouse and Parallel Data Warehouse, you can't set a collation on a local scalar variable.
When i clicked right on my DB , this error appears
"SQL Cannot resolve the collation conflict between "Arabic_100_CI_AI" and "SQL_Latin1_General_CP1_CI_AS" in the equal to operation. Could not use view or function 'dbo.sysdac_instances' because of binding error"
I don't know to change the collation
UPDATE
I tried this code to change default collation of DB But it gives an error
Update2
Please help me to solve this issue.
Thanks in advance.
Your two tables are using different collation. You can tell your query to use a specific collation like this:
SELECT * FROM A JOIN B ON A.Text = B.Text COLLATE SQL_Latin1_General_CP1_CI_AS
Or if you prefer to use the database default collation:
SELECT * FROM A JOIN B ON A.Text = B.Text COLLATE DATABASE_DEFAULT
Updated
I think you need to set the database to single user mode
use master
ALTER DATABASE yourDB SET SINGLE_USER WITH ROLLBACK IMMEDIATE
ALTER DATABASE yourDB MODIFY NAME = [yourDBNew]
ALTER DATABASE yourDBNew SET MULTI_USER
Try below syntax :
SELECT * FROM Table1 PT
JOIN Table2 TA ON PT.Value COLLATE DATABASE_DEFAULT = TA.Value COLLATE DATABASE_DEFAULT
Alter Collation
I need to change the collation of one of our databases on a particular server from Latin1_General_CI_AS to SQL_Latin1_General_CP1_CI_AI so that it matches the rest of our databases.
The Problem
However, when I attempt to do this, I get the following error:
ALTER DATABASE failed. The default collation of database 'XxxxxXxxxxx' cannot be set to SQL_Latin1_General_CP1_CI_AI. (Microsoft SQL Server, Error: 5075)
My Research
My googling on the topic has revealed a number of articles which indicate that I need to export all the data, drop the database, re-create it with the correct collation, then re-import the data.
For example: Problem with database collation change (SQL Server 2008)
Obviously this is a significant task, especially since primary-foreign key relationships must be preserved, and our database is quite large (over ten million data rows).
My Question
Is there a way to change the collation of an existing SQL Server 2012 database which does not require exporting and re-importing all the data?
Alternatively, is there some tool or script(s) which can automate this process in a reliable manner?
The following works for me on SQL Server 2012:
ALTER DATABASE CURRENT COLLATE SQL_Latin1_General_CP1_CI_AI;
The accepted answer in the linked question is not entirely correct, at least not for SQL Server 2012. It says:
Ahh, this is one of the worst problems in SQL Server: you cannot change the collation once an object is created (this is true both for tables and databases...).
But I was just able to change the default collation and I have tables that are populated. The MSDN page for ALTER DATABASE states in the "Remarks" section, under "Changing the Database Collation":
Before you apply a different collation to a database, make sure that the following conditions are in place:
You are the only one currently using the database.
No schema-bound object depends on the collation of the database.
If the following objects, which depend on the database collation, exist in the database, the ALTER DATABASE database_name COLLATE statement will fail. SQL Server will return an error message for each object blocking the ALTER action:
User-defined functions and views created with SCHEMABINDING.
Computed columns.
CHECK constraints.
Table-valued functions that return tables with character columns with collations inherited from the default database collation.
So, I would suggest making sure that the database is in Single-User mode, and that if you have any of those four items, that you:
drop them
change the collation
and then re-add them
BUT, at that point all that has been changed is the Database's default Collation. The Collation of any existing columns in user tables (i.e. non-system tables) will still have the original Collation. If you want existing string columns -- CHAR, VARCHAR, NCHAR, NVARCHAR, and the deprecated TEXT and NTEXT -- to take on the new Collation, you need to change each of those columns individually. And, if there are any indexes defined on those columns, then those indexes will need to be dropped first (disabling is not enough) and created again after the ALTER COLUMN (other dependencies that would prevent the ALTER COLUMN would have already been dropped in order to get the ALTER DATABASE to work). The example below illustrates this behavior:
Test Setup
USE [tempdb];
SET NOCOUNT ON;
CREATE TABLE dbo.ChangeCollationParent
(
[ChangeCollationParentID] INT NOT NULL IDENTITY(1, 1)
CONSTRAINT [PK_ChangeCollationParent] PRIMARY KEY,
ExtendedASCIIString VARCHAR(50) COLLATE Latin1_General_CI_AS NULL,
UnicodeString NVARCHAR(50) COLLATE Latin1_General_CI_AS NULL
);
CREATE TABLE dbo.ChangeCollationChild
(
[ChangeCollationChildID] INT NOT NULL IDENTITY(1, 1)
CONSTRAINT [PK_ChangeCollationChild] PRIMARY KEY,
[ChangeCollationParentID] INT NULL
CONSTRAINT [FK_ChangeCollationChild_ChangeCollationParent] FOREIGN KEY
REFERENCES dbo.ChangeCollationParent([ChangeCollationParentID]),
ExtendedASCIIString VARCHAR(50) COLLATE Latin1_General_CI_AS NULL,
UnicodeString NVARCHAR(50) COLLATE Latin1_General_CI_AS NULL
);
INSERT INTO dbo.ChangeCollationParent ([ExtendedASCIIString], [UnicodeString])
VALUES ('test1' + CHAR(200), N'test1' + NCHAR(200));
INSERT INTO dbo.ChangeCollationParent ([ExtendedASCIIString], [UnicodeString])
VALUES ('test2' + CHAR(170), N'test2' + NCHAR(170));
INSERT INTO dbo.ChangeCollationChild
([ChangeCollationParentID], [ExtendedASCIIString], [UnicodeString])
VALUES (1, 'testA ' + CHAR(200), N'testA ' + NCHAR(200));
INSERT INTO dbo.ChangeCollationChild
([ChangeCollationParentID], [ExtendedASCIIString], [UnicodeString])
VALUES (1, 'testB ' + CHAR(170), N'testB ' + NCHAR(170));
SELECT * FROM dbo.ChangeCollationParent;
SELECT * FROM dbo.ChangeCollationChild;
Test 1: Change column Collation with no dependencies
ALTER TABLE dbo.ChangeCollationParent
ALTER COLUMN [ExtendedASCIIString] VARCHAR(50) COLLATE SQL_Latin1_General_CP1_CI_AI NULL;
ALTER TABLE dbo.ChangeCollationParent
ALTER COLUMN [UnicodeString] NVARCHAR(50) COLLATE SQL_Latin1_General_CP1_CI_AI NULL;
ALTER TABLE dbo.ChangeCollationChild
ALTER COLUMN [ExtendedASCIIString] VARCHAR(50) COLLATE SQL_Latin1_General_CP1_CI_AI NULL;
ALTER TABLE dbo.ChangeCollationChild
ALTER COLUMN [UnicodeString] NVARCHAR(50) COLLATE SQL_Latin1_General_CP1_CI_AI NULL;
SELECT * FROM dbo.ChangeCollationParent;
SELECT * FROM dbo.ChangeCollationChild;
The ALTER COLUMN statements above complete successfully.
Test 2: Change column Collation with dependencies
-- First, create an index:
CREATE NONCLUSTERED INDEX [IX_ChangeCollationParent_ExtendedASCIIString]
ON dbo.ChangeCollationParent ([ExtendedASCIIString] ASC);
-- Next, change the Collation back to the original setting:
ALTER TABLE dbo.ChangeCollationParent
ALTER COLUMN [ExtendedASCIIString] VARCHAR(50) COLLATE Latin1_General_CI_AS NULL;
This time, the ALTER COLUMN statement received the following error:
Msg 5074, Level 16, State 1, Line 60
The index 'IX_ChangeCollationParent_ExtendedASCIIString' is dependent on column 'ExtendedASCIIString'.
Msg 4922, Level 16, State 9, Line 60
ALTER TABLE ALTER COLUMN ExtendedASCIIString failed because one or more objects access this column.
ALSO, please be aware that the Collation of some string columns in database-scoped system catalog views (e.g. sys.objects, sys.columns, sys.indexes, etc) will change to the new Collation. If your code has JOINs to any of these string columns (i.e. name), then you might start getting Collation mismatch errors until you change the Collation on the joining columns in your user tables.
UPDATE:
If changing the Collation for the entire Instance is the desire, or an option, then there is an easier method that bypasses all of these restrictions. It is undocumented and hence unsupported (so if it doesn't work, Microsoft isn't going to help). However, it changes the Collation at all levels: Instance, all Database's, and all string columns in all User Tables. It does this, and avoids all of the typical restrictions, by simply updating the meta-data of the tables, etc to have the new Collation. It then drops and recreates all indexes that have string columns. There are also a few nuances to this method that might have impact, but are fixable. This method is the -q command-line switch of sqlservr.exe. I have documented all of the behaviors, including listing all of the potentially affected areas by doing such a wide-sweeping Collation change, in the following post:
Changing the Collation of the Instance, the Databases, and All Columns in All User Databases: What Could Possibly Go Wrong?
For anyone else stumbling to this problem, the solution is to set DB in single_user mode before change the collation and then set again the multi_user mode after it.
Make sure to not close the connection before setting the multi_user mode!
/* block all other users from connecting to the db */
ALTER DATABASE YorDbName SET SINGLE_USER WITH ROLLBACK IMMEDIATE;
/* modify your db collate */
ALTER DATABASE CURRENT COLLATE SQL_Latin1_General_CP1_CI_AI;
/* allow again all other users to connect to the db */
ALTER DATABASE YorDbName SET MULTI_USER;
My application's database mydb has different collation than tempdb. I get a lot of exceptions comparing string values between tempdb temporary tables and mydb persistent tables.
It was decided to create mydb with same collation as tempdb.
The collation must be set automatically using script. I've tried this:
DECLARE #SQLCollation sql_variant
SELECT #SQLCollation = DATABASEPROPERTYEX('tempdb', 'Collation')
ALTER DATABASE mydb COLLATE #SQLCollation -- doesn't work
ALTER DATABASE mydb COLLATE Latin1_General_CI_AS -- works, but doesn't suit me because I have to type in collation myself in this SQL
So how do I set the same collation for mydb as for tempdb?
You can't just change DB collation with ALTER DATABASE. This only changes system databases (object names etc). (Dalex's answer)
You have to follow the steps detailed in the answers to Changing SQL Server Database sorting.
Another option to use the COLLATE Database_Default to coerce collation without knowing what it is. See SQL Server error "Implicit conversion of because the collation of the value is unresolved due to a collation conflict." and SQL Server - is there a way to mass resolve collation conflicts
Changing collation of the db will not change the collation of already existing tables in the db.
Another option would be to specify the collation to use when you create your temp table.
create table #TempTable
(
Name varchar(10) collate database_default
)
Your comparisons will then work just fine asuming that all your tables character fields have the same collation as the database.
DECLARE #SQLCollation NVARCHAR(1000)
SELECT #SQLCollation = 'ALTER DATABASE MyDb COLLATE '+CAST(DATABASEPROPERTYEX('Tempdb', 'Collation') as NVARCHAR(1000))
exec (#sqlcollation)