[MySQL] 【原创】MySQL5.7 JSON类型使用介绍

CREATE TABLE json_test(
id INT,
person_desc TEXT
)ENGINE INNODB;

INSERT INTO json_test VALUES (1,'{
  "programmers": [{
    "firstName": "Brett",
    "lastName": "McLaughlin",
    "email": "aaaa"
  }, {
    "firstName": "Jason",
    "lastName": "Hunter",
    "email": "bbbb"
  }, {
    "firstName": "Elliotte",
    "lastName": "Harold",
    "email": "cccc"
  }],
  "authors": [{
    "firstName": "Isaac",
    "lastName": "Asimov",
    "genre": "sciencefiction"
  }, {
    "firstName": "Tad",
    "lastName": "Williams",
    "genre": "fantasy"
  }, {
    "firstName": "Frank",
    "lastName": "Peretti",
    "genre": "christianfiction"
  }],
  "musicians": [{
    "firstName": "Eric",
    "lastName": "Clapton",
    "instrument": "guitar"
  }, {
    "firstName": "Sergei",
    "lastName": "Rachmaninoff",
    "instrument": "piano"
  }]
}');

ALTER TABLE json_test MODIFY person_desc json;

mysql> SELECT id,json_keys(person_desc) as "keys" FROM json_test\G
*************************** 1. row ***************************
  id: 1
keys: ["authors", "musicians", "programmers"]
1 row in set (0.00 sec)

mysql> SELECT json_extract(AUTHORS,'$.lastName[0]') AS 'name', AUTHORS FROM
  -> (
  -> SELECT id,json_extract(person_desc,'$.authors[0][0]') AS "authors" FROM json_test
  -> UNION ALL
  -> SELECT id,json_extract(person_desc,'$.authors[1][0]') AS "authors" FROM json_test
  -> UNION ALL
  -> SELECT id,json_extract(person_desc,'$.authors[2][0]') AS "authors" FROM json_test
  -> ) AS T1
  -> ORDER BY NAME DESC\G
*************************** 1. row ***************************
   name: "Williams"
AUTHORS: {"genre": "fantasy", "lastName": "Williams", "firstName": "Tad"}
*************************** 2. row ***************************
   name: "Peretti"
AUTHORS: {"genre": "christianfiction", "lastName": "Peretti", "firstName": "Frank"}
*************************** 3. row ***************************
   name: "Asimov"
AUTHORS: {"genre": "sciencefiction", "lastName": "Asimov", "firstName": "Isaac"}
3 rows in set (0.00 sec)

mysql> SELECT
  -> json_extract(AUTHORS,'$.firstName[0]') AS "firstname",
  -> json_extract(AUTHORS,'$.lastName[0]') AS "lastname",
  -> json_extract(AUTHORS,'$.genre[0]') AS "genre"
  -> FROM
  -> (
  -> SELECT id,json_extract(person_desc,'$.authors[0]') AS "authors" FROM json
_test
  -> ) AS T\G
*************************** 1. row ***************************
firstname: "Isaac"
 lastname: "Asimov"
  genre: "sciencefiction"
1 row in set (0.00 sec)

mysql> UPDATE json_test
  -> SET person_desc = json_remove(person_desc,'$.authors')\G
Query OK, 1 row affected (0.01 sec)
Rows matched: 1  Changed: 1  Warnings: 0

mysql> SELECT json_contains_path(person_desc,'all','$.authors') as authors_exist
s FROM json_test\G
*************************** 1. row ***************************
authors_exists: 0
1 row in set (0.00 sec)