From 60fb75c9632f4e8725517f4ed0cde7612dce7c43 Mon Sep 17 00:00:00 2001
From: "Rico Sta. Cruz" <rstacruz@users.noreply.github.com>
Date: Fri, 22 Sep 2017 16:12:28 +0800
Subject: [PATCH] postgresql-json: new cheatsheet

---
 _drafts/postgresql-json.md |  41 --------------
 postgresql-json.md         | 113 +++++++++++++++++++++++++++++++++++++
 2 files changed, 113 insertions(+), 41 deletions(-)
 delete mode 100644 _drafts/postgresql-json.md
 create mode 100644 postgresql-json.md

diff --git a/_drafts/postgresql-json.md b/_drafts/postgresql-json.md
deleted file mode 100644
index c190dd99c..000000000
--- a/_drafts/postgresql-json.md
+++ /dev/null
@@ -1,41 +0,0 @@
----
-title: Postgresql JSON
-category: Development
----
-
-```
-SELECT * FROM users WHERE data->>'name' = 'John'
-SELECT data->>'name' AS name FROM users
-```
-
-| Operator | Example          | Description                        | Returns |
-| ----     | ----             | ----                               | ----    |
-| `->`     | `data->2`        | Get array element `2`              | JSON    |
-| `->`     | `data->'name'`   | Get object key `name`              | JSON    |
-| `#>`     | `data#>'{a,b}'`  | Get keypath `a,b` (eg, `data.a.b`) | JSON    |
-| ----     | ----             | ----                               | ----    |
-| `->>`    | `data->>2`       | Get array element `2`              | text    |
-| `->>`    | `data->>'name'`  | Get object key `name`              | text    |
-| `#>`     | `data#>>'{a,b}'` | Get keypath `a,b` (eg, `data.a.b`) | text    |
-
-`>` returns JSON, `>>` returns text.
-
-### Boolean operators
-
-| Operator | Example                                      | Description                     |
-| ----     | ----                                         | ----                            |
-| `?`      | `data ? 'name'`                              | Does `data` have key `name`?    |
-| `?|`     | `data ?| array['a','b']`                     | Does `data` have `a` or `b`?    |
-| `?&`     | `data ?& array['a','b']`                     | Does `data` have `a` and `b`?   |
-| `@>`     | `'{"a":1,"b":2}'::jsonb @> '{"b":2}'::jsonb` | Does `left` include `right`?    |
-| `<@`     | `'{"a":1}'::jsonb <@ '{"a":1,"b":2}'::jsonb` | Does `right` include `left`?    |
-
-When `?`/`?|`/`?&` works on objects, it checks keys; when it works on arrays, it checks for elements.
-
-- `'{"a":1}'::jsonb ? 'a'`
-- `'["a"]'::jsonb ? 'a'`
-
-## References
-
-- <https://www.postgresql.org/docs/9.4/static/functions-json.html>
-- <https://www.postgresql.org/docs/9.4/static/datatype-json.html>
diff --git a/postgresql-json.md b/postgresql-json.md
new file mode 100644
index 000000000..c036aab3d
--- /dev/null
+++ b/postgresql-json.md
@@ -0,0 +1,113 @@
+---
+title: Postgresql JSON
+layout: 2017/sheet
+prism_languages: [sql]
+updated: 2017-09-22
+---
+
+## Operators
+
+### Accessors
+
+```sql
+SELECT * FROM users WHERE data->>'name' = 'John';
+SELECT data->>'name' AS name FROM users;
+```
+{: .-setup}
+
+| Operator       | Description                        | Example          | Returns |
+| ----           | ----                               | ----             | ----    |
+| `->` _int_     | Get array element `2`              | `data->2`        | JSON    |
+| `->` _text_    | Get object key `name`              | `data->'name'`   | JSON    |
+| `#>` _text[]_  | Get keypath `a,b` (eg, `data.a.b`) | `data#>'{a,b}'`  | JSON    |
+| -
+| `->>` _int_    | Get array element `2`              | `data->>2`       | Text    |
+| `->>` _text_   | Get object key `name`              | `data->>'name'`  | Text    |
+| `#>>` _text[]_ | Get keypath `a,b` (eg, `data.a.b`) | `data#>>'{a,b}'` | Text    |
+{: .-headers.-shortcuts}
+
+`>` returns JSON, `>>` returns text.
+
+### Boolean operators
+
+```sql
+SELECT * FROM users WHERE data->tags ? 'admin';
+SELECT data->tags ? 'admin' AS is_admin FROM users;
+```
+{: .-setup}
+
+| Operator      | Description                   | Example                          |
+| ----          | ----                          | ----                             |
+| `?` _str_     | Does `data` have key `name`?  | `data ? 'name'`                  |
+| `?|` _text[]_ | Does `data` have `a` or `b`?  | `data ?| array['a','b']`         |
+| `?&` _text[]_ | Does `data` have `a` and `b`? | `data ?& array['a','b']`         |
+| `@>` _jsonb_  | Does `left` include `right`?  | `data @> '{"b":2}'::jsonb`       |
+| `<@` _jsonb_  | Does `right` include `left`?  | `data <@ '{"a":1,"b":2}'::jsonb` |
+{: .-headers.-shortcuts.-left-align}
+
+When `?`/`?|`/`?&` works on objects, it checks keys; when it works on arrays, it checks for elements.
+
+## Updating
+
+### Arrays and objects
+
+```sql
+UPDATE users SET tags = tags || array['admin'];
+```
+{: .-setup}
+
+| Operator       |  Example                   |  Description
+| ----           |  ----                      |  ----
+| `||` _json_    |  `data || array['a','b']`  |  Concatenate
+| `-` _str_      |  `data - 'a'`              |  Delete a key
+| `-` _int_      |  `data - 1`                |  Delete an array item
+| `#-` _text[]_  |  `data #- '{us,name}'`     |  Delete a path
+{: .-headers.-shortcuts}
+
+Only available in PostgreSQL 9.5+.
+
+### jsonb_set
+
+```sql
+UPDATE users SET data = jsonb_set(data, '{name}', '"John"');
+```
+
+Only available in PostgreSQL 9.5+.
+
+## Functions
+
+#### fn(json) → json
+
+```sql
+jsonb_set(data, '{path}', value)
+jsonb_strip_nulls(data)
+```
+
+#### fn(···) → json
+
+```sql
+to_json("Hello"::text)
+array_to_json('{1,2}'::int[])
+```
+
+#### Iteration
+
+```sql
+SELECT * from json_each('{"a":1, "b":2}')
+SELECT * from json_each_text('{"a":1, "b":2}')
+-- key | value
+```
+
+This is an incomplete list, there's way too many!
+
+See: [JSON functions](https://www.postgresql.org/docs/9.5/static/functions-json.html)
+
+## More examples
+
+- `'{"a":1}'::jsonb ? 'a'`
+- `'["a"]'::jsonb ? 'a'`
+
+## References
+
+- <https://www.postgresql.org/docs/9.5/static/functions-json.html>
+- <https://www.postgresql.org/docs/9.5/static/datatype-json.html>