Getting all results using where clause

Question

I have a function which takes an argument that is used in where clause

function(string x)-->Now this will create a sql query which gives

select colname from tablename where columnname=x;

Now I want this function to give all rows i.e. query equivalent to

select colname from tablename;

when I pass x="All".

I want to create a generic query that when I pass "All" then it should return me all the rows else filter my result.

Answer 1

Just leave the where condition out.

If you really want it that complicated use

where columnname LIKE '%'

which will only filter nulls.

Answer 2

select colname from tablename 
where columnname=(case when @x ="All" then columnname
                  else  @x end)

Answer 3

Try this

select colname from tablename where 1=1

hope the above will work

Answer 4

where 1=1 worked for me, Although where clause was being used all records were selected.

You can also try

[any_column_name]=[column_name_in_LHL]

(LHL=left hand side.)

refer my answer for more details