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can i use temperary variable in where clause

sanjay123456
125 New Member
Dear friends,

see the Following query -----

Expand|Select|Wrap|Line Numbers
  1. SELECT headline, Concat(EXTRACT(YEAR FROM datetime),'-',EXTRACT(MONTH FROM datetime),'-',DAYOFMONTH(datetime)) as abc FROM news_news where catid='1' and  abc>='2007-10-1' and abc<='2007-10-30'

here abc is a temp variable can i use it in where clause in same query ?????

here i excute this but it give

#1054 - Unknown column 'abc' in 'where clause'

plz tell me anyone is it possible or not ????
Oct 27 '07 #1
2 3096
pbmods
5,821 Recognized Expert Expert
Heya, Sanjay.

Please use CODE tags when posting source code:

[CODE=mysql]
MySQL code goes here.
[/CODE]

You can create MySQL variables using the SET keyword:
Expand|Select|Wrap|Line Numbers
  1. SET @variable = 'abc';
  2.  
Oct 27 '07 #2
bartonc
6,596 Recognized Expert Expert
Dear friends,

see the Following query -----

Expand|Select|Wrap|Line Numbers
  1. SELECT headline, Concat(EXTRACT(YEAR FROM datetime),'-',EXTRACT(MONTH FROM datetime),'-',DAYOFMONTH(datetime)) as abc FROM news_news where catid='1' and  abc>='2007-10-1' and abc<='2007-10-30'

here abc is a temp variable can i use it in where clause in same query ?????

here i excute this but it give

#1054 - Unknown column 'abc' in 'where clause'

plz tell me anyone is it possible or not ????
In MySQL, names of temporary variable are not known at the time that the where clause is being parsed. Hence; that will not work. But this works fine (I have a column named "timestamp" which is a DATETIME type):
Expand|Select|Wrap|Line Numbers
  1. SELECT * FROM stations
  2. where `timestamp` between '2007-02-01' and '2007-02-13';
For the desired dates: '2007-02-01' and '2007-02-12'
Oct 27 '07 #3

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