QUERY syntax using cell reference

I found out that single quote > double quote > wrapped in ampersands did work. So, for me it looks like this:

=QUERY('Youth Conference Registration'!C:Y,"select C where Y = '"&A1&"'", 0)

I know this is an old thread but I had the same question as the OP and found the answer:

You are nearly there, the way you can include cell references in query language is to wrap the entire thing in speech marks. Because the whole query is written in speech marks you will need to alternate between ' and " as shown below.

What you would need is this:

=QUERY(Responses!B1:I, "Select B where G contains '"& B1 &"' ")

If you then wanted to refer to multiple cells you could add more like this

=QUERY(Responses!B1:I, "Select B where G contains '"& B1 &"' and G contains '"& B2 &"' ")

The above would filter down your results further based on the contents of B1 and B2.

I only have a workaround here. In this special case, I would use the FILTER function instead of QUERY:

=FILTER(Responses!B:B,Responses!G:G=B1)

Assuming that your data is on the "Responses" sheet, but your condition (cell reference) is in the actual sheet's B1 cell.

Hope it helps.

UPDATE:

After some search for the original question: The problem with your formula is definitely the second & sign which assumes that you would like to concatenate something more to your WHERE statement. Try to remove it. If it still doesn't work, then try this:

=QUERY(Responses!B1:I, "Select B where G matches '^.\*($" & B1 & ").\*$'") - I have not tried it, but it helped in another post: Query with range of values for WHERE clause?

Copied from Web Applications:

=QUERY(Responses!B1:I, "Select B where G contains '"&$B1&"'")