#+TITLE: SQL layer

#+TAGS: dsl|layer|programming

[[file:img/sql.png]]

* Table of Contents                     :TOC_5_gh:noexport:
- [[#description][Description]]
  - [[#features][Features:]]
- [[#install][Install]]
  - [[#external-dependencies][External Dependencies]]
  - [[#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 [[https://github.com/mjibson/sqlfmt][=sqlfmt=]]
- Snippet insertion for the more general SQL constructs.
- REPL support via =SQLi= buffer.
- Automatic capitalization of keywords.
- LSP support via [[https://github.com/lighttiger2505/sqls][sqls]].

* 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.

** External Dependencies
Some functionality, like linting, rely on external binaries:
- *Syntax Checking*: Install [[https://www.ruby-lang.org/en/about/][ruby]] and the =sqlint= gem.

#+BEGIN_SRC ruby
  gem install sqlint
#+END_SRC

- *Formatting*: Install [[https://github.com/mjibson/sqlfmt][sqlfmt]] and move it into your =$PATH=

#+BEGIN_SRC sh
  # Download and extract the binary 0.4.0 for linux
  wget -q -O - https://github.com/mjibson/sqlfmt/releases/latest/download/sqlfmt_0.4.0_linux_amd64.tar.gz | tar -xpvzf - --directory "${installdir}/bin"
#+END_SRC

- *LSP supporting (sqls)*:
  - Install [[https://golang.org/dl/][Go]]lang and [[https://github.com/lighttiger2505/sqls][sqls]], then setting the variable =sql-backend= to ='lsp=.
  - One of way to connect DB is setting variable =sql-lsp-sqls-workspace-config-path= to ='workspace= or ='root= and put json file at these directory.

#+BEGIN_SRC emacs-lisp
  (setq-default dotspacemacs-configuration-layers '(
    (sql :variables
         sql-backend 'lsp
         sql-lsp-sqls-workspace-config-path 'workspace)))
#+END_SRC

#+BEGIN_SRC json
{
  "sqls": {
    "connections": [
      {
        "driver": "mysql",
        "dataSourceName": "user1:password1@tcp(localhost:3306)/sample_db"
      }
    ]
  }
}
#+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 c~ | connect to a SQLi buffer from your saved buffer list |
| ~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 l~ | Send the current line to the SQLi buffer and move to the next line =insert state=                     |
| ~SPC m s L~ | Send the current line to the SQLi buffer and move to the next line 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

| Key binding | Description                                                  |
|-------------+--------------------------------------------------------------|
| ~SPC m = c~ | capitalize SQL keywords in region (if capitalize is enabled) |
| ~SPC m = =~ | ~sqlfmt~ whole buffer                                        |
| ~SPC m = r~ | ~sqlfmt~ active region                                       |