Selecting data using varyng source column

Question

I am wondering if there is a way to select "like". For example i have columns h1, h2, h3 i want my select to pick which column to grab based on user input.

Select like "user var will be 1,2 or 3" from table

Can you have a varying select or will i have to do Select * from table and then filter my data table?

Another though I had was through having it add the h onto the users var in C#

Select 'h" + var + " ' from table

Robbert · Accepted Answer · 2014-12-08T20:25:25.720

1

You could build the query on the fly:

int col = Convert.ToInt32(request["usercolumn"]);
string q = "SELECT h" + col + " FROM table";

My c# is a bit weak, but the gist here is take the user input, make sure it's an integer and build your query using the user input.

edited Dec 08 '14 at 20:25

answered Dec 08 '14 at 20:19

Robbert

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This is what i waslooking to do i had ' ' around it and it was failing lol, so i was looking for otherways, took the extra ' ' off and works great thanks. – Dec 08 '14 at 20:25

score 0 · Answer 2 · edited May 23 '17 at 11:51

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SELECT * is typically bad practice. If you did something like the data table filtering I would specify the possible columns explicitly. I would also look at using dynamic SQL. Dynamically choose column in SQL query

edited May 23 '17 at 11:51

Community

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answered Dec 08 '14 at 20:19

db_brad

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score 0 · Answer 3 · answered Dec 08 '14 at 20:28

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Robbert code will work but if use will enter greater than 3 then that will give error, better to use case like this

DECLARE @col int  = 1
select case @col when 1 then h1
                 When 2 then h2
                 Else h3 END
From table

answered Dec 08 '14 at 20:28

Ali Adravi

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Selecting data using varyng source column

3 Answers3