Shell Programming and Scripting

I am performing some operation like:

SQL Statement below:

Code:

UPDATE table2 SET column1_table2 = ( SELECT column1_table1
FROM table1 WHERE column2_table1 = column2_table2 LIMIT 1)
LIMIT 2;

So what I'm trying to do is to find a corresponding value and then I'm adding it into table2. Now how can I actually delete this value after this has been added to table2 immediately?

I could see that only a value is updated in the table and not deleted.
Is that you are interested in doing updation and deletion simultaneously ?

and by deleting a value ==> its only a record that can be deleted and not the column alone.

Yeah... For example.. consider the instance when we execute the statement and it iterates to find records that match the criteria... the output changes from:

Code:

Table 1:
121::::ABCDE::::::0.2
230:::::ASDS:::::::0.6
xxx::::::jaksd:::::::0.7
xxx::::::dasdd:::::::0.3
xxx::::::asaaa:::::::0.1
xxx::::::ddddd:::::::0.5

Table 2:
121::::ABCDE
230:::::ASDS
343::::::jaksd
545::::::dasdd
656::::::asaaa
344::::::ddddd

to

There's a change right? Thats the only thing I want... It'll search for the string in Table_2, fetch the corresponding value and then update the same in Table1. I don't know the internal workings of SQL but what I was thinking was that if I delete the record which was just checked from Table_2, i can actually speed up the process of updating because it would then have to check less records each time it is checking.... Correct me if I'm wrong please... And the context in which I'm talking has some million records and thus I'm searching for a good way to speed up things...