Tag: sql

A Quick INSERT INTO Trick

From time to time you’re going to need to move some data from one table into another, in particular to generalize or specialize code. I’ve seen amazingly large code blocks written to handle simple cases as this, and here’s a simple trick you’re going to need some day:

INSERT INTO 
    
    (field_1, field_2) 
SELECT
    some_field, some_other_field 
FROM 
    


You can also add conditionals, i.e. to retrieve rows that might have been inserted yesterday, etc:


INSERT INTO 
    

    (field_1, field_2) 
SELECT
    some_field, some_other_field 
FROM 
    
WHERE
    condition = 1


The good thing about this is that all data movement is kept within the database server, so that the data doesn’t have to travel from the server, to the client and then back from the client to the server again. It’s blazingly fast compared to other methods. You can also do transformations with regular SQL functions in your SELECT statement, which should help you do very simple operations at the speed of light.