SQLYoga- Adding Computed Columns in SQL Server
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Addin
gComputed 
 Columns 
in  SQL 
Server
02/07
A scenario that required me to 
 add  one calculated column  
came up today. When a   
column is computed, it can be  
used in queries just like any  
other column and allows us to  
change one or more columns  
from the same table.
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Lets try it:
Create One Table: tblTestComputed 
 CREATE TABLE 
tblTestComputed(  FirstName 
VARCHAR(50),
LastName VARCHAR(50)
)
Lets insert some data into it:
INSERT INTO 
tblTestComputed(FirstName, 
LastName)  SELECT 'Tejas', 'Shah'
UNION
SELECT 'Hiral', 'Shah'
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04/0
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So now I run:
SELECT * FROM 
tblTestComputed
I will get output like:
output
W W W . S Q L Y O G A . 
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05/0
7
I now require the display  
name to be something like  
"Shah Tejas" or "Shah Hiral". 
 I therefore created a  new  
column and named it:
ALTER TABLE tblTestComputed
ADD FullName AS (ISNULL(LastName,'') + ' ' + ISNULL(FirstName,'')) 
 So, now if I run:
SELECT * FROM tblTestComputed
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06/0
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I will get output like:
output
W W W . S Q L Y O G A . 
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07/0
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Add a  computed column  
called FullName to your table 
 to combine first and last  
names, updating  
automatically.
However, it's essential to note 
 that computed columns  
cannot be updated directly  
since they are derived from  
other columns.
For a  deeper dive into  
computed columns and their 
 applications, click here to  
learn more.
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