Select columns only if they exist

Question

How can I select columns even if I don't know whether they exist in a particular table?

So something like:

SELECT if_exists(col1, col2), col3
FROM tab1;

The result would only be the content of columns, that really exist in the tab1.

Background: I want to make a dynamic query with PHP, where the table will be dynamically inserted. Most tables have the same structure (same column names), but some of them have slightly different column names. Changing the names is not an option for some reasons.

Possibly useful: http://stackoverflow.com/questions/3395798/mysql-check-if-a-column-exists-in-a-table-with-sql — wogsland, Feb 02 '17 at 16:58

Fuzzy · Answer 1 · 2017-02-02T17:22:58.667

0

try this:

SELECT IF (EXISTS
    (SELECT 1
    FROM   information_schema.columns
    WHERE  table_name = 'my_table'
          AND column_name = 'col1')
,
    col1 , col2), col3   FROM   tab1

edited Feb 02 '17 at 17:22

answered Feb 02 '17 at 17:06

Fuzzy

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I get `Unrecognized statement type (near "IF EXISTS" at position 0)`. – Evgenij Reznik Feb 02 '17 at 17:14

Select columns only if they exist

1 Answers1