PostGreSql - data extraction jsonb

This article describes how to extract value jsonb type of a key field in the PostGreSql

Reference: https://www.cnblogs.com/mywebnumber/p/5551092.html

First, the simple mode

1. only one{}

   # rule_config 字段格式
   {
     "cardType": 1,
     "sellPrice": null,
     "originPrice": 15
   }
   
   # 获取cardType
   SELECT
       rule_config -> 'cardType' AS cardType 
   FROM
       t_free_ride_card_rule_config 
   WHERE
       title = '测试0211'

   　　
2. only one[]

   # Rule_config Field Format
    [ 
     "ZERO", 
     "One", 
     "TWO" 
   ] 
   
   # Get the first element of 
   the SELECT 
       rule_confi G -> 0   the AS the cardType 
    the FROM 
       t_free_ride_card_rule_config 
   the WHERE 
       title  =  '0211 test'

    

3. Two parallel {}

   # rule_config字段格式
   [
     {
       "ruleGuid": "1125720873758932994",
       "mcardType": 1,
       "packStart": "2020-02-14",
       
     },
     {
       "ruleGuid": "1073055433702576129",
       "mcardType": 1,
       "packExpire": "2020-02-18"
     }
   ]
   
   # 获取key为ruleGuid 和 ruleGuid 的值
   SELECT
       json_array_elements ( rule_config :: json ) -> 'ruleGuid' AS ruleGuid,
       json_array_elements ( rule_config :: json ) -> 'mcardType' AS mcardType 
   FROM
       t_free_ride_card_rule_config 
   WHERE
       title = '测试0211'

    

Second, complex formatting

• Data format jsonb

  [
    {
      "platform": 0,
      "cardPackage": [
        {
          "ruleGuid": "1125720873758932994",
          "mcardType": 1,
          "packStart": "2020-02-14",
          "packExpire": "2020-02-15"
        },
        {
          "ruleGuid": "1073055433702576129",
          "mcardType": 1,
          "packStart": "2020-02-16",
          "packExpire": "2020-02-18"
        }
      ],
      "platformExpire": "2020-02-18"
    }
  ]

   

• Sql get related fields

  # 第一种，嵌套sql
  SELECT
      bottom :: json ->> 'ruleGuid' AS ruleGuid 
  FROM
      (
      SELECT
          json_array_elements ( cardPackage ) AS bottom 
      FROM
          ( SELECT expire_info :: json -> 'cardPackage' AS cardPackage FROM ( SELECT expire_info :: json -> 0 AS expire_info FROM t_ev_month_card WHERE user_new_id = '1200107139' ) AS A ) AS B 
      ) The AS F.
   
  Description: 
  The first layer sql: the SELECT expire_info JSON :: -> 0 the AS expire_info the FROM t_ev_month_card the WHERE user_new_id = '1200107139' acquired an outermost {data}, a column named expire_info 
  second layer sql: from outermost curly braces expire_info acquired key = "cardPackage" content expire_info :: json -> 'cardPackage' , a column named cardPackage 
  third layer sql: column contents cardPackage {} into separate 
  fourth layer sql :} ruleGuid removed from each individual field {(see a, (1) section)

  
  # 第二种，
  SELECT (json_array_elements((expire_info -> 0):: json ->'cardPackage'))->'ruleGuid' AS a
  FROM t_ev_month_card WHERE user_new_id = '1200107139'
  

   If the data type is jsonb, may be replaced json to jsonb:

　　

SELECT
    bottom :: jsonb -> 'ruleGuid' AS ruleGuid 
FROM
    (
    SELECT
        jsonb_array_elements ( cardPackage ) AS bottom 
    FROM
        (
        SELECT
            expire_info :: jsonb -> 'cardPackage' AS cardPackage 
        FROM
            (
            SELECT
                expire_info :: jsonb -> 0 AS expire_info 
            FROM
                t_ev_month_card 
            WHERE
                user_new_id = '1200107139' 
            ) AS A 
        ) AS B 
    ) AS F