topic where 1=1? in QlikView

where 1=1?

Fri, 11 May 2012 09:20:27 GMT

I have seen that some people write

"select

lastname

firstname

from

customer

where 1=1"

The purpose of haveing "where 1=1"? What result would it gain?

where 1=1?

Mon, 14 May 2012 21:57:15 GMT

I believe this is used to generate a permanently 'true' boolean statement, perhaps to force that a database to return a resulset. However this shouldn't be necessary unless the database from which you are getting data is buggy, and doesn't return data sometimes, using a statement that forces a "true" on the query, may get the job done.

best

where 1=1?

rwunderlich — Mon, 14 May 2012 23:12:08 GMT

As Jorge indicated, it's an "always true" clause. It logically has the same effect as no where clause. I've seen two uses in QV script.

1. As a placeholder, commonly used when variables are used to generate the SQL statement. The WHERE is a fixed bit of text and the 1=1 avoids a syntax error when you want no clause.

2. As a way to force an unoptimized load from a QVD. In that case you would see it in a LOAD statement rather than a SQL SELECT.

-Rob

Re: where 1=1?

dyy — Thu, 28 Jun 2018 17:37:49 GMT

what is the reason to force an unoptimized load?

Re: where 1=1?

rwunderlich — Fri, 29 Jun 2018 04:40:24 GMT

A few items don't work as optimized loads. For example, mapping table loads. Can't recall others at the moment.

-Rob

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