Update query using Subquery in Sql Server

Question

I have a simple table Structure like this:

Table tempData

╔══════════╦═══════╗
║   NAME   ║ MARKS ║
╠══════════╬═══         


        

Answer 1

you can join both tables even on UPDATE statements,

UPDATE  a
SET     a.marks = b.marks
FROM    tempDataView a
        INNER JOIN tempData b
            ON a.Name = b.Name

• SQLFiddle Demo

for faster performance, define an INDEX on column marks on both tables.

using SUBQUERY

UPDATE  tempDataView 
SET     marks = 
        (
          SELECT marks 
          FROM tempData b 
          WHERE tempDataView.Name = b.Name
        )

• SQLFiddle Demo