How do I swap column values in sql server 2008?
SqlSql ServerSql Server-2008Sql Problem Overview
I have a table called Employee
Eno ename AttributeValue AttributeName
1 aa a123 abc
2 bbb b123 dcf
3 cc c7sd wew3
I want to swap the data from column AttributeValue
to AttributeName
and AttributeName
to AttributeValue
For Example:
Eno ename AttributeValue AttributeName
1 aa abc a123
2 bbb dcf b123
3 cc wew3 c7sd
Sql Solutions
Solution 1 - Sql
UPDATE employee
SET AttributeValue = AttributeName,
AttributeName = AttributeValue
However, unless both columns have the exact same definition, you risk losing information.
Solution 2 - Sql
Update employee
Set attributeValue = attributeName,
attributeName = attributeValue
Solution 3 - Sql
update Employee set AttributeValue = AttributeName, AttributeName = AttributeValue
Solution 4 - Sql
All the previous techniques are slow for big tables they move data instead of renaming columns, this is a simple solution:
ALTER TABLE "amplitude"
RENAME COLUMN "start_hour_displayed" TO "temp";
ALTER TABLE "amplitude"
RENAME COLUMN "start_hour" TO "start_hour_displayed";
ALTER TABLE "amplitude"
RENAME COLUMN "temp" TO "start_hour";
If you have views of functions linked you have to backup them before and restore them after.
Solution 5 - Sql
This is really good example
SELECT * from employees;
Go
DECLARE @temp as varchar(20)
update employees
set @temp = fname,
fname = lname,
lname = @temp
WHERE deptno = 10;
GO
SELECT * from employees;
Solution 6 - Sql
Declare @myTable Table (id int, first_name varchar(50), last_name varchar(50));
Select * from Student
Insert Into @myTable (id, first_name, last_name) Select id, last_name, first_name from Student
MERGE
INTO Student std
USING @myTable tmp
ON std.id = tmp.id
WHEN MATCHED THEN
UPDATE
SET std.first_name = tmp.first_name,
std.last_name = tmp.last_name;
Select * from Student
Output
Solution 7 - Sql
Just swap both columns in a single update:
Update registration
Set AttributeName = AttributeValue ,
AttributeValue = AttributeName where id in (1,2,3)
Solution 8 - Sql
UPDATE employee SET AttributeValue = AttributeName, AttributeName = AttributeValue its not correct better to create one temp column and try the code UPDATE employee SET temp= AttributeName then again UPDATE employee SET AttributeName = AttributeValuee again
UPDATE employee SET AttributeValuee= temp