How do I swap column values in sql server 2008?

Question

I have a table called Employee

 Eno     ename     AttributeValue      AttributeName  
 1       aa           a123             abc
 2       bbb          b123           


        

Answer 1

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.

Answer 2

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

Answer 3

Update employee
Set attributeValue = attributeName,
    attributeName = attributeValue

Answer 4

Just swap both columns in a single update:

Update registration
Set AttributeName = AttributeValue ,
    AttributeValue = AttributeName where id in (1,2,3)

Answer 5

UPDATE employee
SET AttributeValue = AttributeName, 
    AttributeName = AttributeValue

However, unless both columns have the exact same definition, you risk losing information.

Answer 6

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