#+TITLE: SQL layer

#+TAGS: dsl|layer|programming

[[file:img/sql.png]]

* Table of Contents                     :TOC_5_gh:noexport:
- [[#description][Description]]
  - [[#features][Features:]]
- [[#install][Install]]
  - [[#sql-keywords-capitalization][SQL Keywords Capitalization]]
    - [[#sql-interactive-mode][SQL Interactive Mode]]
    - [[#blacklisting-keywords][Blacklisting keywords]]
  - [[#auto-indent][Auto-Indent]]
- [[#key-bindings][Key bindings]]
  - [[#highlighting][Highlighting]]
  - [[#inferior-process-interactions-sqli][Inferior Process Interactions (SQLi)]]
    - [[#send-sql-queries-to-sqli][Send SQL queries to SQLi:]]
  - [[#sqli-buffer][SQLi buffer]]
  - [[#code-formatting][Code Formatting]]

* Description
This layer adds support for a wide range of SQL dialects to Spacemacs.

** Features:
- Syntax highlighting for the following SQL dialects
  - ANSI
  - DB2
  - Informix
  - Ingres
  - Interbase
  - Linter
  - Microsoft
  - MySQL
  - Oracle
  - Postgres
  - Solid
  - SQLite
  - Sybase
  - Vertica
- Syntax-checking via [[https://github.com/purcell/sqlint][sqlint]] for ANSI SQL.
- Format code with =sqlfmt=
- Snippet insertion for the more general SQL constructs.
- REPL support via =SQLi= buffer.
- Automatic capitalization of keywords.

* Install
To use this configuration layer, add it to your =~/.spacemacs=. You will need to
add =sql= to the existing =dotspacemacs-configuration-layers= list in this
file.

For syntax-checking you also need to install [[https://www.ruby-lang.org/en/about/][ruby]] as well as =sqlint=.

#+BEGIN_SRC ruby
  gem install sqlint
#+END_SRC

** SQL Keywords Capitalization
SQL, by convention, uses upper-case keywords, although lower-case works just as
well. As humans, the separation between upper-case and lower-case helps scan and
parse the code much more quickly.

To install [[https://github.com/Trevoke/sqlup-mode.el][sqlup-mode]] which enables auto capitalization in =sql mode= set the
variable =sql-capitalize-keywords= to =t=.

#+BEGIN_SRC emacs-lisp
  (setq-default dotspacemacs-configuration-layers '(
    (sql :variables sql-capitalize-keywords t)))
#+END_SRC

*** SQL Interactive Mode
If you want capitalization only in =sql-mode= and not in =sql-interactive-mode=
you can set the variable =sql-capitalize-keywords-disable-interactive= to =t=.

*** Blacklisting keywords
[[https://github.com/Trevoke/sqlup-mode.el][sqlup-mode]] can be configured to ignore certain keywords. For example if you use
=name= as column name it would be annoying to have it upcased. You can prevent
this behaviour by setting the variable =sql-capitalize-keywords-blacklist= to
a list with keywords to ignore, e.g.

#+BEGIN_SRC emacs-lisp
  (setq-default dotspacemacs-configuration-layers '(
    (sql :variables
         sql-capitalize-keywords t
         sql-capitalize-keywords-blacklist '("name" "varchar"))))
#+END_SRC

This layer is blacklisting =name= by default as it is a very common name for
column and NAME is non-reserved SQL keyword.

** Auto-Indent
This mode use [[https://github.com/alex-hhh/emacs-sql-indent][sql-indent]] to indent the code. You can check the package's README
to adjust the rules. If that's not what you want, you can also disable
auto-indent by setting the variable =sql-auto-indent= to =nil=.

#+BEGIN_SRC emacs-lisp
  (setq-default dotspacemacs-configuration-layers '(
    (sql :variables sql-auto-indent nil)))
#+END_SRC

* Key bindings
** Highlighting

| Key binding | Description                       |
|-------------+-----------------------------------|
| ~SPC m h k~ | select a SQL dialect to highlight |

** Inferior Process Interactions (SQLi)

| Key binding | Description                 |
|-------------+-----------------------------|
| ~SPC m b b~ | show the SQLi buffer name   |
| ~SPC m b s~ | set the SQLi buffer         |
| ~SPC m l a~ | List all objects            |
| ~SPC m l t~ | list all objects in a table |

*** Send SQL queries to SQLi:

| Key binding | Description                                                                           |
|-------------+---------------------------------------------------------------------------------------|
| ~SPC m s b~ | Send the whole buffer to the SQLi buffer                                              |
| ~SPC m s B~ | Send the whole buffer to the SQLi buffer and switch to it in =insert state=           |
| ~SPC m s i~ | Start the SQLi process                                                                |
| ~SPC m s f~ | Send the paragraph around point to the SQLi buffer                                    |
| ~SPC m s F~ | Send the paragraph around point to the SQLi buffer and switch to it in =insert state= |
| ~SPC m s q~ | Prompt for a string to send to the SQLi buffer                                        |
| ~SPC m s Q~ | Prompt for a string to send to the SQLi buffer and switch to it in =insert state=     |
| ~SPC m s r~ | Send the selected region to the SQLi buffer                                           |
| ~SPC m s R~ | Send the selected region to the SQLi buffer and switch to it in =insert state=        |

** SQLi buffer

| Key binding | Description                                                  |
|-------------+--------------------------------------------------------------|
| ~SPC m b r~ | rename buffer (follow up in the SQL buffer with ~SPC m b s~) |
| ~SPC m b S~ | save the current connection                                  |

** Code Formatting

| ~SPC m = c~ | capitalize SQL keywords in region (if capitalize is enabled) |