1. Get a specific value in a single json string
Function: get_json_object (single json, '$.Field to get')
Example:
Code: SELECT get_json_object('{"NAME":"Zhang San","ID":"1"}','$.NAME') as name;
SELECT get_json_object(‘{“NAME”:“张三”,“ID”:“1”}’,‘$.NAME’);
2. json_tuple
Syntax: json_tuple(json_string, k1, k2 ...)
Description: Parse the string json_string of json, specify multiple keys in json data, and return the corresponding value. Returns NULL if the input json string is invalid.
Example:
select b.name ,b.age from tableName a lateral view json_tuple('{"name":"zhangsan","age":18}','name','age') b as name,age;
Note: Not in the above json_tuple function . If you add it when using the jsontuple function. If you add it when using the json_tuple function.If you are using j so ntWhen the u pl e function is added , the parsing will fail.
Hive parses the json array
1. Nested subqueries parse the json array
select good_id,get_json_object(sale_json,'$.monthSales') as monthSales from tableName LATERAL VIEW explode(split(goods_id,','))goods as good_id LATERAL VIEW explode(split(regexp_replace(regexp_replace(json_str , '\\[|\\]',''),'\\}\\,\\{','\\}\\;\\{'),'\\;')) sales as sale_json;
select t1.* from (
select
t0.*
,get_json_object(tmp.task_per_step_definition, '$.daysOfMedication') as daysOfMedication
,get_json_object(tmp.task_per_step_definition, '$.dosageForm') as dosageForm
,get_json_object(tmp.task_per_step_definition, '$.drugCode') as drugCode
,get_json_object(tmp.task_per_step_definition, '$.frequency') as frequency
,get_json_object(tmp.task_per_step_definition, '$.frequencyName') as frequencyName
,get_json_object(tmp.task_per_step_definition, '$.groupNo') as groupNo
,get_json_object(tmp.task_per_step_definition, '$.medicineName') as medicineName
,get_json_object(tmp.task_per_step_definition, '$.price') as price
,get_json_object(tmp.task_per_step_definition, '$.remark') as remark
,get_json_object(tmp.task_per_step_definition, '$.route') as route
,get_json_object(tmp.task_per_step_definition, '$.routeName') as routeName
,get_json_object(tmp.task_per_step_definition, '$.singleDose') as singleDose
,get_json_object(tmp.task_per_step_definition, '$.singleDoseUnit') as singleDoseUnit
,get_json_object(tmp.task_per_step_definition, '$.specification') as specification
,get_json_object(tmp.task_per_step_definition, '$.totalDose') as totalDose
,get_json_object(tmp.task_per_step_definition, '$.totalDoseUnit') as totalDoseUnit
,get_json_object(tmp.task_per_step_definition, '$.unitPrice') as unitPrice
from wedw_dwd.pg_med_risk_emr_western_medicine_prescription_df t0
lateral view explode(split(regexp_replace(regexp_replace(regexp_replace(t0.medicines,'^\\[\\{', '\\{'), '\\}\\]$', '\\}'), '\\}\\,\\{\\"nodeId\\"', '\\}\\@\\#\\{\\"nodeId\\"'), '\\@\\#')) tmp as task_per_step_definition
where t0.date_id = date_sub(current_date(),1)
and t0.org_name like '%辛口%'
) t1