11–20 of 158 posts
> Avoid SELECT title, last_name, first_name FROM books LEFT JOIN authors ON books.author_id = authors.id > Prefer SELECT b.title, a.last_name, a.first_name FROM books AS b LEFT JOIN authors AS a ON b.author_id = a.id Couldn't disagree more. One letter abbreviations hurt readability IMO.
Does anybody else like putting from first? I find it makes the auto complete sooo much better and easier to read.
> Avoid SELECT title, last_name, first_name FROM books LEFT JOIN authors ON books.author_id = authors.id > Prefer SELECT b.title, a.last_name, a.first_name FROM books AS b LEFT JOIN authors AS a ON b.author_id = a.id Couldn't disagree more. One letter abbreviations hurt readability IMO.
Does anybody else like putting from first? I find it makes the auto complete sooo much better and easier to read.
https://en.wikipedia.org/wiki/FLWOR
SELECT first_name FROM person WHERE first_name LIKE 'john'
becomes:
FROM person WHERE first_name LIKE 'john' SELECT first_name
SQL reads more English like while from first is more Yoda speak but the auto-complete is worth more to me.
> Avoid SELECT title, last_name, first_name FROM books LEFT JOIN authors ON books.author_id = authors.id > Prefer SELECT b.title, a.last_name, a.first_name FROM books AS b LEFT JOIN authors AS a ON b.author_id = a.id Couldn't disagree more. One letter abbreviations hurt readability IMO.
SELECT t1.thing
, t2.stuff
, t3.stuffagain
, t4.more
FROM SomeTable t1
JOIN TableThatLinksToSelf t2 ON
JOIN TableThatLinksToSelf t3 ON
JOIN AnotherTable t4 ON
> Avoid SELECT title, last_name, first_name FROM books LEFT JOIN authors ON books.author_id = authors.id > Prefer SELECT b.title, a.last_name, a.first_name FROM books AS b LEFT JOIN authors AS a ON b.author_id = a.id Couldn't disagree more. One letter abbreviations hurt readability IMO.
> Avoid SELECT title, last_name, first_name FROM books LEFT JOIN authors ON books.author_id = authors.id > Prefer SELECT b.title, a.last_name, a.first_name FROM books AS b LEFT JOIN authors AS a ON b.author_id = a.id Couldn't disagree more. One letter abbreviations hurt readability IMO.
It seems to be a matter of personal preference, but I've never liked single-character aliases myself, and never understood why so many seem to.
I prefer descriptive table and other object names, and abbreviate them in aliases within queries (though usually not to single letters).
>LIKE compares characters, and can be paired with wildcard operators like %, whereas the = >operator compares strings and numbers for exact matches. The = can take advantage of indexed columns. Unless this specific to certain databases, LIKE can take advantage of indexes too, without wildcards LIKE should be nearly identical in performance to = both seeking the index. >Using wildcards for searching can be expensive.…
At least for the latest versions of every database. If you go back to a version from 10+ years ago there's no guarantees.
>LIKE compares characters, and can be paired with wildcard operators like %, whereas the = >operator compares strings and numbers for exact matches. The = can take advantage of indexed columns. Unless this specific to certain databases, LIKE can take advantage of indexes too, without wildcards LIKE should be nearly identical in performance to = both seeking the index. >Using wildcards for searching can be expensive.…
LIKE 'abc%' will use indexes but LIKE '%abc' will not. At least for the latest versions of every database. If you go back to a version from 10+ years ago there's no guarantees.
It can only do a seek if there are character before the wildcard: 'ab%c', 'abc%' and 'abc' getting progressively faster due to less index entries transversed.