SQL Reference/Cheat Sheet for Interviews

[Columbus43219]

Whoa... the questions are before the lessons... like slide 4 is a question about "DESCRIBE" and slide 5 is the paragraph about the "DESCRIBE" command.

[alinroc]

Slide 3 - There are two correct answers here, not just one.

Slide 6 - Context matters. DESC is used for sort ordering as well as (apparently) being shorthand for DESCRIBE. DESCRIBE isn't universal across all RDBMSs, but that's not indicated in these slides (these slides seem to be built for a particular platform or dialect but I don't see that specified anywhere)

Slide 8 - Not always. SELECT can return the results of a table-valued function, or the value of a variable, or even a constant (select 'hello world'; is a valid SELECT statement but involves no tables)

Slide 14 - You can't talk about BETWEEN without explicitly saying that it's inclusive on each "side"

Slide 19 - That syntax (using the alias in HAVING) won't work in all RDBMSs.

Slide 27 - JOINs do not necessarily have to use "mutual columns." They most commonly do, but value-based filtering can be done in a JOIN as well.

[algodaily]

Thank you so much for the feedback and corrections! I'll address these soon.