Обсуждение: SQL is fetching results BLANK checks but the data has no BLANKS

> On 05/07/2023 23:10 CEST M Sarwar <sarwarmd02@outlook.com> wrote:
>
> Data in the database is uploaded using python.
>
> I have tried to test the same results by creating a sample table where I
> inserted some sample data. In my sample test, I do not see any discrepancies.
>
> ------------------------------
> From: M Sarwar <sarwarmd02@outlook.com>
>  Sent: Wednesday, July 5, 2023 5:01 PM
>  To: pgsql-admin@lists.postgresql.org <pgsql-admin@lists.postgresql.org>
>  Subject: SQL is fetching results BLANK checks but the data has no BLANKS
>
> SELECT TEST_NUMBER
>  FROM BRONX.TEST_TEST_DETAILS_ALL_MCM
>  WHERE LEFT(TEST_DESCRIPTION, 1) = ' '
> ;
> The above SQL is fetching lot of data but when I take closer look at the data
> in the table TEST_TEST_DETAILS_ALL_MCM, I see no prefixed BLANKS in the column
> TEST_DESCRIPTION.
>
> test_description character varying(50) COLLATE pg_catalog."default", -- TEST_DESCRIPTION, type
>
> What could be the reason here for fetching the data when I do not have the
> data which has prefixes of BLANK , ‘ ‘.

Is there a functional index on left(test_description, 1) ?  My guess is that
the index is corrupted.  This can be fixed with REINDEX.

--
Erik

> On 05/07/2023 23:34 CEST M Sarwar <sarwarmd02@outlook.com> wrote:
>
> Table has no indexes so far.

Do you get the same results when using LIKE instead?

    SELECT test_number
    FROM bronx.test_test_details_all_mcm
    WHERE test_description LIKE ' %'

--
Erik