I have a table in SQL server 2008.
I need a column that until now wasn't necessary, not to allow NULL anymore, without droping the table.
I tried to do something like this:
ALTER TABLE [Sessions] ALTER COLUMN region_id NOT NULL;
EDIT: It was a small syntax error. solved.
You have to specify the data type as well when you alter a column:
ALTER TABLE [Sessions] ALTER COLUMN region_id int /* ? */ NOT NULL;
you are missing datatype.
ALTER TABLE [Sessions] ALTER COLUMN region_id int NOT NULL;
You have to first set all values that are NULL to a non NULL value:
UPDATE [Sessions]
SET region_id=-1
WHERE region_id IS NULL
Instead of -1 you should choose something that would represent the formerly NULL values so you may distinguish them.
To get away with saving prevention you may go on:
Tools>Options>Designers> and unclick Prevent Saving Changes that require table re-creation
First off to save table chances like this you need to either script the changes, or when saving from the UI, you need to set SSMS to drop and recreate table for you. To do this;
Go to Tools
Options
Designers
UNTICK prevent saving changes that require table re-creations.
If you script the changes, you will need to first alter the table, and add a new column allowing nulls. Then update the column and remove nulls and then after you will be able to set the column to NOT NULL.
If you follow these steps you will solve your issue.
I am working on an SQL Database, I have a column named "Price". When the database was created the column "Price" was set to NVARCHAR I need to change its type to decimal(18, 2) without losing the data in the database. This should be done by an SQL Script
I thought of creating a new column, moving the data to it, remove the old column, and then rename the newly created column.
Can someone help me with an example on how to do this?
Also is there a function in SQL to Parse string to decimal?
Thanks
You don't need to add a new column two times, just remove the old one after updating the new one:
ALTER TABLE table_name ADD new_column_name decimal(18,2)
update table_name
set new_column_name = convert(decimal(18,2), old_column_name)
ALTER TABLE table_name DROP COLUMN old_column_name
Note that if the old_column_name is not numeric, the convert may fail.
Something Like
Alter Table [MyTable] Add Column NewPrice decimal(18,2) null
Then
Update [MyTable] Set NewPrice = Convert(decimal(18,2),[Price]) Where Price is not null
If the above fails then you'll need to beef it up to deal with the funnies
Once you are happy drop the old column with an Alter Table and rename the new one with sp_rename
If you just want to change only column's data type, you can do like this=>
Alter Table YourTableName
Alter Column ColumnName DataType
I already test this on SQL server 2012 and its work.
You can make those changes visually using Management Studio. Then, use the button "Generate Change Script" to get the script for the changes you made. Be sure to do all testing in a copy of the original ddbb, in case something goes wrong..
How do I add a column after another column within MS SQL by using SQL query?
TempTable
ID int,
Type nvarchar(20),
Active bit
NewTable
ID int,
Type nvarchar(20),
Description text,
Active bit
That is what I want, how do I do that
Assuming MySQL (EDIT: posted before the SQL variant was supplied):
ALTER TABLE myTable ADD myNewColumn VARCHAR(255) AFTER myOtherColumn
The AFTER keyword tells MySQL where to place the new column. You can also use FIRST to flag the new column as the first column in the table.
It depends on what database you are using. In MySQL, you would use the "ALTER TABLE" syntax. I don't remember exactly how, but it would go something like this if you wanted to add a column called 'newcol' that was a 200 character varchar:
ALTER TABLE example ADD newCol VARCHAR(200) AFTER otherCol;
In a Firebird database the AFTER myOtherColumn does not work but you can try re-positioning the column using:
ALTER TABLE name ALTER column POSITION new_position
I guess it may work in other cases as well.
How to change column order in a table using SQL query in SQL Server 2005?
I want to rearrange column order in a table using SQL query.
You cannot. The column order is just a "cosmetic" thing we humans care about - to SQL Server, it's almost always absolutely irrelevant.
What SQL Server Management Studio does in the background when you change column order there is recreating the table from scratch with a new CREATE TABLE command, copying over the data from the old table, and then dropping it.
There is no SQL command to define the column ordering.
You have to explicitly list the fields in the order you want them to be returned instead of using * for the 'default' order.
original query:
select * from foobar
returns
foo bar
--- ---
1 2
now write
select bar, foo from foobar
bar foo
--- ---
2 1
according to https://learn.microsoft.com/en-us/sql/relational-databases/tables/change-column-order-in-a-table
This task is not supported using Transact-SQL statements.
Well, it can be done, using create/ copy / drop/ rename, as answered by komma8.komma1
Or you can use SQL Server Management Studio
In Object Explorer, right-click the table with columns you want to reorder and click Design (Modify in ver. 2005 SP1 or earlier)
Select the box to the left of the column name that you want to reorder. (You can select multiple columns by holding the [shift] or
the [ctrl] keys on your keyboard.)
Drag the column(s) to another location within the table.
Then click save. This method actually drops and recreates the table, so some errors might occur.
If Change Tracking option is enabled for the database and the table, you shouldn't use this method.
If it is disabled, the Prevent saving changes that require the table re-creation option should be cleared in Tools menu > Options > Designers, otherwise "Saving changes is not permitted" error will occur.
Disabling the Prevent saving changes that require the table re-creation option is strongly advised against by Microsoft, as it leads to the existing change tracking information being deleted when the table is re-created, so you should never disable this option if Change Tracking is enabled!
Problems may also arise during primary and foreign key creation.
If any of the above errors occurs, saving fails which leaves you with the original column order.
In SQLServer Management Studio:
Tools -> Options -> Designers -> Table and Database Designers
Unselect 'Prevent saving changes that require table re-creation'.
Then:
right click the table you want to re-order the columns for.
click 'Design'.
Drag the columns to the order you want.
finally, click save.
SQLServer Management studio will drop the table and recreate it using the data.
This is similar to the question on ordering the records in the result of a query .. and typically no one likes the formally correct answer ;-)
So here it goes:
as per SQL standard, the columns in a table are not "ordered"
as a result, a select * does not force the columns to be returned in a particular order
typically, each RDBMS has a kind of "default" order (usually the order that the columns were added to the table, either in the create table' or in thealter table add ` statements
therefore, if you rely on the order of columns (because you are using the results of a query to poulate some other datastructure from the position of the columns), explicitly list the columns in the order you want them.
You can of course change the order of the columns in a sql statement. However if you want to abstract tables' physical column order, you can create a view. i.e
CREATE TABLE myTable(
a int NULL,
b varchar(50) NULL,
c datetime NULL
);
CREATE VIEW vw_myTable
AS
SELECT c, a, b
FROM myTable;
select * from myTable;
a b c
- - -
select * from vw_myTable
c a b
- - -
You can do it by creating a new table, copy all the data over, drop the old table, then renaming the new one to replace the old one.
You could also add new columns to the table, copy the column by column data over, drop the old columns, then rename new columns to match the old ones. A simple example below:
http://sqlfiddle.com/#!3/67af4/1
CREATE TABLE TestTable (
Column1 INT,
Column2 VARCHAR(255)
);
GO
insert into TestTable values(1, 'Test1');
insert into TestTable values(2, 'Test2');
GO
select * from TestTable;
GO
ALTER TABLE TestTable ADD Column2_NEW VARCHAR(255);
ALTER TABLE TestTable ADD Column1_NEW INT;
GO
update TestTable
set Column1_NEW = Column1,
Column2_NEW = Column2;
GO
ALTER TABLE TestTable DROP COLUMN Column1;
ALTER TABLE TestTable DROP COLUMN Column2;
GO
sp_rename 'TestTable.Column1_NEW', 'Column1', 'COLUMN';
GO
sp_rename 'TestTable.Column2_NEW', 'Column2', 'COLUMN';
GO
select * from TestTable;
GO
In SQLServer Management Studio:
Tools -> Options -> Designers -> Table and Database Designers
Unselect Prevent saving changes that require table re-creation.
Now you can reorder the table.
Sql server internally build the script. It create a temporary table with new changes and copy the data and drop current table then recreate the table insert from temp table. I find it from "Generate Change script" option ssms 2014. Script like this. From Here: How to change column order in a table using sql query
BEGIN TRANSACTION
SET QUOTED_IDENTIFIER ON
SET ARITHABORT ON
SET NUMERIC_ROUNDABORT OFF
SET CONCAT_NULL_YIELDS_NULL ON
SET ANSI_NULLS ON
SET ANSI_PADDING ON
SET ANSI_WARNINGS ON
COMMIT
BEGIN TRANSACTION
GO
CREATE TABLE dbo.Tmp_emps
(
id int NULL,
ename varchar(20) NULL
) ON [PRIMARY]
GO
ALTER TABLE dbo.Tmp_emps SET (LOCK_ESCALATION = TABLE)
GO
IF EXISTS(SELECT * FROM dbo.emps)
EXEC('INSERT INTO dbo.Tmp_emps (id, ename)
SELECT id, ename FROM dbo.emps WITH (HOLDLOCK TABLOCKX)')
GO
DROP TABLE dbo.emps
GO
EXECUTE sp_rename N'dbo.Tmp_emps', N'emps', 'OBJECT'
GO
COMMIT
If your table has enough columns then you can try this. First create a new table with preferred order of columns.
create table new as select column1,column2,column3,....columnN from table_name;
Now drop the table using drop command
drop table table_name;
now rename the newly created table to your old table name.
rename new to table_name;
now select the table, you have your columns rearranged as you preferred before.
select * from table_name;
Not sure if still relevant, but SSMS can generate a change scripts for this.
Re-order (drag the column) the table in Designer View
Click on 'Generate Change Script'
The generated script contains the script which does the following:
Create a temporary table
Adds the constraints, relationships and triggers from original table to temporary table
Drop original table
Rename temporary table to original table name
If you have not yet added any data into your table yet, there is one way to move the columns around.
Try this:
In SSMS, click Tools > Options > Designers > Table and Database Designers > Uncheck the box next to Prevent saving changes that require table re-creation > Click OK.
In the object tree, right-click on your table and select Design > in the thin column to the left of the Column Name column, you can click and drag the columns around to wherever you want them. When you're done, just go to close the Design tab and SSMS will ask you if you want to save your changes, click OK.
Optional:
3. Re-enable the checkbox for the option from Step 1 to re-secure your table.
Hope this helps someone!
Credit goes to Microsoft:
https://learn.microsoft.com/en-us/troubleshoot/sql/ssms/error-when-you-save-table#more-information
At the end of the day, you simply cannot do this in MS SQL. I recently created tables on the go (application startup) using a stored Procedure that reads from a lookup table. When I created a view that combined these with another table I had manually created earlier one (same schema, with data), It failed - simply because I was using ''Select * UNION Select * ' for the view. At the same time, if I use only those created through the stored procedure, I am successful.
In conclusion: If there is any application which depends on the order of column it is really not good programming and will for sure create problems in the future. Columns should 'feel' free to be anywhere and be used for any data process (INSERT, UPDATE, SELECT).
You can achieve it with these steps:
remove all foreign keys and primary key of the original table.
rename the original table.
using CTAS create the original table in the order you want.
drop the old table.
apply all constraints back to the original table
If the columns to be reordered have recently been created and are empty, then the columns can be deleted and re-added in the correct order.
This happened to me, extending a database manually to add new functionality, and I had missed a column out, and when I added it, the sequence was incorrect.
After finding no adequate solution here I simply corrected the table using the following kind of commands.
ALTER TABLE tablename DROP COLUMN columnname;
ALTER TABLE tablename ADD columnname columntype;
Note: only do this if you don't have data in the columns you are dropping.
People have said that column order does not matter. I regularly use SQL Server Management Studio "generate scripts" to create a text version of a database's schema. To effectively version control these scripts (git) and to compare them (WinMerge), it is imperative that the output from compatible databases is the same, and the differences highlighted are genuine database differences.
Column order does matter; but just to some people, not to everyone!
Use
SELECT * FROM TABLE1
which displays the default column order of the table.
If you want to change the order of the columns.
Specify the column name to display correspondingly
SELECT COLUMN1, COLUMN5, COLUMN4, COLUMN3, COULMN2 FROM TABLE1
you can use indexing.. After indexing, if select * from XXXX results should be as per the index, But only result set.. not structrue of Table
In order to have a specific column order You need to select column by column in the order You wish.
Selection order dictates how columns will be ordered in output.
Try this command:
alter table students modify age int(5) first;
This will change the position of age to the first position.
You can change this using SQL query. Here is sql query to change the sequence of column.
ALTER TABLE table name
CHANGE COLUMN `column1` `column1` INT(11) NOT NULL COMMENT '' AFTER `column2`;
alter table name modify columnname int(5) first;
will bring the column to first
alter table name modify columnname int(5) after (tablename);
This worked for me on Oracle DB:
select column1, column2, t.* from table t
Example: Change position of field_priority after field_price in table status.
ALTER TABLE `status` CHANGE `priority` `priority` INT(11) NULL DEFAULT NULL AFTER `price`;
If I wish to simply rename a column (not change its type or constraints, just its name) in an SQL database using SQL, how do I do that? Or is it not possible?
This is for any database claiming to support SQL, I'm simply looking for an SQL-specific query that will work regardless of actual database implementation.
Specifically for SQL Server, use sp_rename
USE AdventureWorks;
GO
EXEC sp_rename 'Sales.SalesTerritory.TerritoryID', 'TerrID', 'COLUMN';
GO
On PostgreSQL (and many other RDBMS), you can do it with regular ALTER TABLE statement:
=> SELECT * FROM Test1;
id | foo | bar
----+-----+-----
2 | 1 | 2
=> ALTER TABLE Test1 RENAME COLUMN foo TO baz;
ALTER TABLE
=> SELECT * FROM Test1;
id | baz | bar
----+-----+-----
2 | 1 | 2
In MySQL, the syntax is ALTER TABLE ... CHANGE:
ALTER TABLE <table_name> CHANGE <column_name> <new_column_name> <data_type> ...
Note that you can't just rename and leave the type and constraints as is; you must retype the data type and constraints after the new name of the column.
Unfortunately, for a database independent solution, you will need to know everything about the column. If it is used in other tables as a foreign key, they will need to be modified as well.
ALTER TABLE MyTable ADD MyNewColumn OLD_COLUMN_TYPE;
UPDATE MyTable SET MyNewColumn = MyOldColumn;
-- add all necessary triggers and constraints to the new column...
-- update all foreign key usages to point to the new column...
ALTER TABLE MyTable DROP COLUMN MyOldColumn;
For the very simplest of cases (no constraints, triggers, indexes or keys), it will take the above 3 lines. For anything more complicated it can get very messy as you fill in the missing parts.
However, as mentioned above, there are simpler database specific methods if you know which database you need to modify ahead of time.
I think this is the easiest way to change column name.
SP_RENAME 'TABLE_NAME.OLD_COLUMN_NAME','NEW_COLUMN_NAME'
In sql server you can use
exec sp_rename '<TableName.OldColumnName>','<NewColumnName>','COLUMN'
or
sp_rename '<TableName.OldColumnName>','<NewColumnName>','COLUMN'
In Informix, you can use:
RENAME COLUMN TableName.OldName TO NewName;
This was implemented before the SQL standard addressed the issue - if it is addressed in the SQL standard. My copy of the SQL 9075:2003 standard does not show it as being standard (amongst other things, RENAME is not one of the keywords). I don't know whether it is actually in SQL 9075:2008.
You can use the following command to rename the column of any table in SQL Server:
exec sp_rename 'TableName.OldColumnName', 'New colunmName'
ALTER TABLE is standard SQL. But it's not completely implemented in many database systems.
The standard would be ALTER TABLE, but that's not necessarily supported by every DBMS you're likely to encounter, so if you're looking for an all-encompassing syntax, you may be out of luck.
Alternatively to SQL, you can do this in Microsoft SQL Server Management Studio, from the table Design Panel.
First Way
Slow double-click on the column. The column name will become an editable text box.
Second Way
SqlManagement Studio>>DataBases>>tables>>specificTable>>Column
Folder>>Right Click on column>>Reman
Third Way
Table>>RightClick>>Design
To rename you have to change the column
e.g
Suppose
*registration is Table Name
newRefereeName is a column name That I want to change to refereeName
SO my SQL Query will be*
ALTER TABLE 'registration' CHANGE 'newRefereeName' 'refereeName' VARCHAR(100) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NOT NULL;
exec sp_rename 'Tablename.OldColumnName', 'NewColumnName', 'Column';