Var in sql

This article is tagged with: Var in sql and mysql

var in sql

One way of doing this is to use database variables
create table testcalc (
id int(11) not null auto_increment,
num1 int(11) default null,
num2 int(11) default null,
num3 int(11) default null,
num4 int(11) default null,
primary key(id)
);
insert into testcalc values
(default, 1, 2, 3, 4),
(default, 5, 10, 15, 20);
Then you can get the same results as in your example by storing the calculation results in variable syntax like this
@youVar := (calc) as resultName01
Then it will be available to following calculations to use like this
(@youVar + newCalc) as resultName02
We can apply it to your example like this
select
id,
num1,
num2,
num3,
num4,
@1plus2 := (num1 + num2) as 1plus2, # create var01
@1plus2mult3 := (@1plus2 * num3) as 1plus2mult3, # create var02 using var01
@sumOfCalc := (@1plus2 + @1plus2mult3) as sumOfCalc # create var03 using var01 and var02
from testcalc;

This article is tagged with: Var in sql and mysql