On Tue, Sep 5, 2017 at 3:00 PM, Stephen Chrzanowski <pontia...@gmail.com>
wrote:
> On behalf of Cecil, the fault in that logic is that count(*) returns the
> number of rows in that table, not whether there is a hole "somewhere: Your
> query will either return 1, or, 0.
>
>
I either don't understand you, or I am doing something wrong. I used "a"
instead of "Last Used" in my example because I'm just plain lazy.
QLite version 3.14.2 2016-09-12 18:50:49
Enter ".help" for usage hints.
Connected to a transient in-memory database.
Use ".open FILENAME" to reopen on a persistent database.
sqlite> create table x (a date,b integer);
sqlite> insert into x values(NULL, 1);
sqlite> insert into x values(NULL, 2);
sqlite> insert into x values('2017-09-01', 2);
sqlite> insert into x values('2017-09-02', 3);
sqlite> insert into x values('2017-09-04', 4);
sqlite> select count(*) from x;
5
sqlite> select count(*) from x where a is NULL;
2
sqlite> select count(*) from x where a is NOT NULL;
3
sqlite>
--
Caution! The OP is an hyperpolysyllabicsesquipedalianist and this email may
cause stress to those with hippopotomonstrosesquipedaliophobia.
Maranatha! <><
John McKown
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