Re: Insert data if it is not existing

On 05/23/2018 04:58 PM, tango ward wrote:
> Thanks masters for responding again.
>
> I've tried running the code:
>
> INSERT INTO my_table(name, age)
> SELECT name, age
> WHERE NOT EXISTS(SELECT name FROM my_table WHERE name= name)

The first thing I see is that:

SELECT name, age

is not being selected from anywhere, for example:

SELECT name, age FROM some_table.

The second thing I see is why not use ON CONFLICT?

>
>
> this doesn't give me error but it doesn't insert data either.
>
> On Thu, May 24, 2018 at 3:35 AM, Adrian Klaver
> <adrian(dot)klaver(at)aklaver(dot)com <mailto:adrian(dot)klaver(at)aklaver(dot)com>> wrote:
>
> On 05/23/2018 10:00 AM, David G. Johnston wrote:
>
> On Wednesday, May 23, 2018, tango ward <tangoward15(at)gmail(dot)com
> <mailto:tangoward15(at)gmail(dot)com> <mailto:tangoward15(at)gmail(dot)com
> <mailto:tangoward15(at)gmail(dot)com>>> wrote:
>
>     I just want to ask if it's possible to insert data if it's not
>     existing yet.
>
>
> This seems more like a philosophical question than a technical
> one...
> ​but the answer is yes:
>
> CREATE TABLE test_t (a varchar, b varchar, c integer);
> INSERT INTO test_t
> SELECT '1', '2', 3 WHERE false;​ --where false causes the data
> to effectively "not exist"
>
> As for ON CONFLICT: conflicts can only happen between things
> that exist.
>
>
> Well that made my day:)
>
>
> David J.
>
>
>
> --
> Adrian Klaver
> adrian(dot)klaver(at)aklaver(dot)com <mailto:adrian(dot)klaver(at)aklaver(dot)com>
>
>

--
Adrian Klaver
adrian(dot)klaver(at)aklaver(dot)com