what does this symbol mean := in sql

Question

what does this mean

:=

in sql ?

if found some sql using like that symbol example

select col1, col2, @pv:=col3 as 'col3' from table1
join
(select @pv:=1)tmp
where col1=@pv

Thank you in advance.

[`:=`](http://dev.mysql.com/doc/refman/4.1/en/assignment-operators.html#operator_assign-value) is assignment operator. — Grijesh Chauhan, Dec 19 '14 at 06:53

score 12 · Answer 1 · edited May 23 '17 at 10:29

12

using this: here variable are prepended with an @ sign to suggest user-defined variable.A variable, without @, is a system variable, which you cannot define yourself.

SET  @pv:=1// we set a variable

i.e := is used as assignment operator like normal = else where.

see here:http://dev.mysql.com/doc/refman/5.0/en/user-variables.html

and also see a good post here:MySQL: @variable vs. variable. Whats the difference?

edited May 23 '17 at 10:29

Community

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answered Dec 19 '14 at 06:52

Suchit kumar

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Thank you.what about the @ ? – ashTon Dec 19 '14 at 06:55
@ashTon @ sign to suggest user-defined variable. – Suchit kumar Dec 19 '14 at 06:58

what does this symbol mean := in sql

1 Answers1