can i use temperary variable in where clause

[sanjay123456]

Dear friends,

see the Following query -----

[code=mysql]
SELECT headline, Concat(EXTRACT( YEAR FROM datetime),'-',EXTRACT(MONTH FROM datetime),'-',DAYOFMONTH(da tetime)) as abc FROM news_news where catid='1' and abc>='2007-10-1' and abc<='2007-10-30'[/code]


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 ????

[pbmods]

Heya, Sanjay.

Please use CODE tags when posting source code:

&#91;CODE=my sql]
MySQL code goes here.
&#91;/CODE]

You can create MySQL variables using the SET keyword:
[code=mysql]
SET @variable = 'abc';
[/code]

[bartonc]

Dear friends,

see the Following query -----

[code=mysql]
SELECT headline, Concat(EXTRACT( YEAR FROM datetime),'-',EXTRACT(MONTH FROM datetime),'-',DAYOFMONTH(da tetime)) as abc FROM news_news where catid='1' and abc>='2007-10-1' and abc<='2007-10-30'[/code]


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):[CODE=mysql]SELECT * FROM stations
where `timestamp` between '2007-02-01' and '2007-02-13';[/CODE]For the desired dates: '2007-02-01' and '2007-02-12'