[sql] How to change column order in a table using sql query in sql server 2005?

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.

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!

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

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.

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.

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 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

Try this command:

alter table students modify age int(5) first; 

This will change the position of age to the first position.

I suppose you want to add a new column in a specific position. You can create a new column by moving current columns to the right.

+---+---+---+
| A | B | C |
+---+---+---+

Remove all affected indexes and foreign key references. Add a new column with the exact same data type like the last column and copy data there.

+---+---+---+---+
| A | B | C | C |
+---+---+---+---+
          |___^

Change data type of the third column to the same type like the previous column and copy data there.

+---+---+---+---+
| A | B | B | C | 
+---+---+---+---+
      |___^

Rename columns accordingly, recreate removed indexes and foreign key references.

+---+---+---+---+
| A | D | B | C | 
+---+---+---+---+

Change data type of the second colum.

Keep in mind that the column order is just a "cosmetic" thing like marc_s said.

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.

according to http://msdn.microsoft.com/en-us/library/aa337556.aspx

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

1. In Object Explorer, right-click the table with columns you want to reorder and click Design (Modify in ver. 2005 SP1 or earlier)
2. 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.)
3. 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.

alter table name modify columnname int(5) first; will bring the column to first alter table name modify columnname int(5) after (tablename);

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`;

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

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:

1. remove all foreign keys and primary key of the original table.

2. rename the original table.

3. using CTAS create the original table in the order you want.

4. drop the old table.

5. apply all constraints back to the original table

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

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;

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 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`;