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Murari Jha

why we use where 1=1 in sql query

3 Replies

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Daniel Jones9y ago
Take a look at these linlks
http://dba.stackexchange.com/questions/54954/why-use-where-1-or-where-1-1
http://stackoverflow.com/questions/1264681/what-is-the-purpose-of-using-where-1-1-in-sql-statements
0
Rafnas T P9y ago
where 1 = 1 is used to force the statement to pass, It is use full in dynamic queries when we are adding conditions for select statement based on parameter,you can append always 'and [condition]'

For example,
str1='select * from student where 1=1'
if(@gen=='M')
begin
str1+='and Gender=1'
end
if(@gen=='F')
begin
str1+='and Gender=0'
end
0
Nitin Sontakke9y ago
Two reasons that I can think of. There might be more possible.
1/ Personally, I use it to quickly comment out the WHERE conditions in the sql statement.
For example:
select column1
,column2
,column3
from table1
where 1 = 1
and condition1
and condition2
and condition3

While in the process of testing this sql, I can just put -- (comment in sql) next to any of the condition and keep on pressing F5 (Execute).
2/ In old days (may be even today!) there were days when developers use to create the WHERE clause of the statement dynamically. Before adding each new clause they have to check at least one condition is in place. If yes, then they have to add AND otherwise empty string.
In stead of keep on checking this while adding new condition, it is prudent to add just where dummy WHERE 1 = 1 at the beginning of the query and then always add AND. Simple.
+1