3 ms·
Something other which is hard is writing performant queries. Using statements with subqueries/in syntax for example. And I always forget which join does what.
by myspy 5y ago
Something other which is hard is writing performant queries. Using statements with subqueries/in syntax for example.
And I always forget which join does what.
- AdrianB1 5y agoRemembering which join does what is easy: inner joins strictly joins the tables, left takes all on left (first table), right takes all on right (second table), outer (or cross) join are so rarely used you don't need to memorize.
- Semaphor 5y ago> outer (or cross) join are so rarely used you don't need to memorize. I’d say they are more important to know than right joins.
- MeinBlutIstBlau 5y agosame with the joins. on paper it makes sense, in practice it does not. if its more than a "select * from dbo.whatever where column abc = 'thing'" i have to refer back to notes and play with it.
- eurasiantiger 5y agoBasically inner/left/right is a choice on how you want your NULLs: do you want all the rows that match, all the rows on the left, or all the rows on the right?
- deleted 5y ago[deleted]