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Indentation rules

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@ -5,7 +5,7 @@
These are guidelines to help you write SQL queries that will be easier to read. These are guidelines to help you write SQL queries that will be easier to read.
Remember that even if you hate a given style at first, generally speaking it is Remember that even if you hate a given style at first, generally speaking it is
far more important that we have _any_ agreed upon style than that we all like it, far more important that we have _any_ agreed upon style than that we all like it,
and furthermore the odds are that you will eventually learn to like it once you and furthermore the odds are that you will eventually learn to like it once you
start to follow it. start to follow it.
@ -163,7 +163,10 @@ Although not exhaustive always include spaces:
comma or semicolon. comma or semicolon.
```sql ```sql
SELECT a.title, a.release_date, a.recording_date SELECT
a.title,
a.release_date,
a.recording_date
FROM albums AS a FROM albums AS a
WHERE a.title = 'Charcoal Lane' WHERE a.title = 'Charcoal Lane'
OR a.title = 'The New Danger'; OR a.title = 'The New Danger';
@ -199,8 +202,8 @@ WHERE title = 'The New Danger';
```sql ```sql
SELECT a.title, SELECT a.title,
a.release_date, a.release_date,
a.recording_date, a.recording_date,
a.production_date a.production_date
FROM albums AS a FROM albums AS a
WHERE a.title = 'Charcoal Lane' WHERE a.title = 'Charcoal Lane'
@ -213,14 +216,24 @@ To ensure that SQL is readable it is important that standards of indentation
are followed. are followed.
**ONLY** the fundamental keywords - `SELECT`, `FROM`, `WHERE`, `GROUP BY`, `HAVING`, `LIMIT`, **ONLY** the fundamental keywords - `SELECT`, `FROM`, `WHERE`, `GROUP BY`, `HAVING`, `LIMIT`,
and `ORDER BY`should be fully left justified. Other clauses should be indented to the end of and `ORDER BY`should be fully left justified.
that keyword.
For single `SELECT`s, you can use the single line form:
```sql ```sql
SELECT first_name, SELECT first_name
last_name, FROM rappers
is_still_tippin_on_four_fours, ```
is_still_wrapped_in_four_vogues
If you are `SELECT`ing more than one column, place all selects on their own line indented 2
spaces in a block after the `SELECT` keyword.
```sql
SELECT
first_name,
last_name,
is_still_tippin_on_four_fours,
is_still_wrapped_in_four_vogues
FROM rappers FROM rappers
WHERE first_name = 'Mike' WHERE first_name = 'Mike'
AND last_name = 'Jones' AND last_name = 'Jones'
@ -228,6 +241,7 @@ WHERE first_name = 'Mike'
This allows the reader to quickly scan for the important building blocks of the query. This allows the reader to quickly scan for the important building blocks of the query.
#### Joins #### Joins
Joins should be indented 2 spaces right from the `FROM` keyword Joins should be indented 2 spaces right from the `FROM` keyword
@ -277,27 +291,30 @@ FROM my_tmp_table
#### Sub-queries #### Sub-queries
In PostgreSQL you should probably be doing subqueries with `WITH` clauses. In PostgreSQL you should be doing subqueries with `WITH` clauses and avoiding the use of inline
subqueries.
Sub-queries should be left aligned 2 spaces to the right of the opening parentheses and then In MySQL or other query engines that do not support `WITH`, sub-queries should be left aligned 2
laid out using the same style as a `WITH` statement w/r/t parentheses. spaces to the right of the opening parentheses and then laid out using the same style as a `WITH`
statement w/r/t parentheses.
```sql ```sql
SELECT r.last_name, SELECT
( r.last_name,
SELECT MAX(YEAR(championship_date)) (
FROM champions AS c SELECT MAX(YEAR(championship_date))
WHERE c.last_name = r.last_name FROM champions AS c
AND c.confirmed = 'Y' WHERE c.last_name = r.last_name
) AS last_championship_year AND c.confirmed = 'Y'
) AS last_championship_year
FROM riders AS r FROM riders AS r
WHERE r.last_name IN WHERE r.last_name IN
( (
SELECT c.last_name SELECT c.last_name
FROM champions AS c FROM champions AS c
WHERE YEAR(championship_date) > '2008' WHERE YEAR(championship_date) > '2008'
AND c.confirmed = 'Y' AND c.confirmed = 'Y'
) )
``` ```
#### Case statements (PostreSQL) #### Case statements (PostreSQL)