I have a simple JSON Document with Countries:
Doc ID Countries
{
"type": "countries",
"countries": [
{
"name": "Argentina",
"code": "AR"
},
{
"name": "Armenia",
"code": "AM"
}
]}
Doc ID: CarSample
{
"countryCode": "AR",
"brand": "Mercedez",
"type": "car"
}
Now I am trying to make a simple join between these 2:
SELECT * FROM BucketName AS Countries
JOIN BucketName AS cars ON Countries.countries[0].code=cars.countryCode
WHERE cars.type="car" AND Countries.type="countries";
I ran them with cbq and WebConsole both triggers
a Syntax error. On VERSION 5.1 of Couchbase
I created different type of index but no change on the result.
Can you please help me understand what is wrong it?
ANSI JOINS are supported only in CB 5.50
Pre CB 5.50 supports LOOKUP and Index Joins
Related
I am building a .net core web api using Dapper and Oracle 19c. The application will receive a POST request similar to the one below, and needs to return a value (Salary) from the same table. It needs to loop over the JSON and return the salary filtering on name, id, and year that match relational data in an Employees table which also contains the salary and other information for each employee. I am new to Oracle and especially working with JSON. I tried to use JSON_TABLE, but can't get that to work. What is an easy way to do this?
Request
POST
{
"Employees": [
{
"EMPLOYEE_ID": "100",
"FIRST_NAME":"Steven",
"LAST_NAME": "King",
"HIRE_DATE": "17-JUN-03"
},
{
"EMPLOYEE_ID": "101",
"FIRST_NAME":"Neena",
"LAST_NAME": "Kochar",
"HIRE_DATE": "21-SEP-05"
},
{
"EMPLOYEE_ID": "104",
"FIRST_NAME":"Bruce",
"LAST_NAME": "Ernst",
"HIRE_DATE": "21-MAY-07"
}
]
}
Response
{
"Employees": [
{
"SALARY": "100000",
"STATUS":"SUCCESS"
},
{
"SALARY": "100000",
"STATUS":"SUCCESS"
},
{
"SALARY": "100000",
"STATUS":"SUCCESS"
}
]
}
I tried something like the below query and get "column ambiguously defined" error at line 2 Column 8.
I've tried some other variations of this, but I think I'm using JSON_TABLE wrong and maybe trying to do something that can't be done with JSON functions in Oracle 19c. I'm not sure of the best way to approach this and having trouble making sense of the Oracle documentation and articles. I'm also kind of new with APIs, but can easily do a simple GET request to this table with Dapper and return employee information in JSON.
SELECT *
FROM EMPLOYEES e
JOIN EMPLOYEES e ON e.EMPLOYEE_ID IN(
SELECT jt.* FROM JSON_TABLE(
'{
"Payees": [
{
"EMPLOYEE_ID": "100",
"FIRST_NAME":"Steven",
"LAST_NAME": "King",
"HIRE_DATE": "17-JUN-03"
}
]
},
'COLUMNS(EMPLOYEE_ID VARCHAR2(20) PATH '$.EMPLOYEE_ID')) AS jt
);
Final solution:
select e.salary FROM EMPLOYEES e WHERE e.EMPLOYEE_ID IN (SELECT jt.* FROM JSON_TABLE( q'~{ "Payees": [ { "EMPLOYEE_ID": "100", "FIRST_NAME":"Steven", "LAST_NAME": "King", "HIRE_DATE": "17-JUN-03" } ] }~', '$.Payees[*]' COLUMNS(EMPLOYEE_ID VARCHAR2(20) PATH '$.EMPLOYEE_ID')) AS jt) ;
In PostgreSQL database I have a json column called json. Data inside look like below:
{
"Version": "0.0.0.1",
"Items": [
{
"Id": "40000000-0000-0000-0000-000000141146",
"Name": "apple",
"Score": 64,
"Value": 1430000
},
{
"Id": "40000000-0000-0000-0000-000000141147",
"Name": "grapefruit",
"Score": 58,
"Value": 1190000
},
{
"Id": "40000000-0000-0000-0000-000000141148",
"Name": "mango",
"Score": 41,
"Value": 170000
}
]
}
What I would like to do is retrieving all Score data from Items elements.
I was trying to use SQL code:
select
substring(json ->> 'Items' from '"Score": (\d*),') as score
from vegetables;
However that returns just the score from first element instead of 3. I was trying to use '\g' flag which supposed to find all results globally, but the code was not working.
Could anyone advise how to do that properly? Thanks in advance!
Considering that the data type of json field is jsonb then no need to use substring or regex, simply lateral join with jsonb_array_elements will do the required things for you. Try below query.
select x->>'Score' "Score" from vegetables
cross join lateral jsonb_array_elements(json->'Items') x
DEMO
If i have json like the following in a column in a mysql database
[
{
"name": "John",
"checked": true
},
{
"name": "Lucy",
"checked": false
}
]
how can I select in mysql all rows where in the same object name = 'John' and checked = true.
The json objects may have more keys and keys may not be in a specific order.
Just use JSON_CONTAINS:
SELECT * from `users`
WHERE JSON_CONTAINS(`data`, '{"name": "John","checked": true}');
You can try to match the string if the keys are always in the same order. Assuming your column is called people
SELECT
IF(people LIKE '%[
{
\"name\": \"John\",
\"checked\": true%', TRUE, FALSE) AS 'john_checked'
FROM table
WHERE (people LIKE '%[
{
\"name\": \"John\",
\"checked\": true%')
With the knowledge of this solution, you could create a shorter SQL such as the following. You may use this alone, or use it as a subquery within the where clause of a query that will return all the rows.
SELECT
IF(people LIKE '%\"checked\": true%', TRUE, FALSE) AS 'john_checked'
FROM table
WHERE (people LIKE '%\"name\": \"John\"%')
You can probably see in this that JSON is not ideal for storing in mySQL.
The better solution is to design your database as a relational one, i.e. have an additional table called people and a column(s) that link the data. Saying how to design this would require me to know much more about your data/subject, but you should learn about SQL "joins" and normalisation.
There are other questions that discuss JSON in mySQL, such as Storing JSON in database vs. having a new column for each key and Storing Data in MySQL as JSON
As of mySQL 5.7 there are some json related functions. See this wagon article, and the mySQL documentation.
Here is how it can be done in postgresql:
create table users (data jsonb);'
insert into users values ('[{"name": "John", "checked": "true"}, {"name": "Lucy", "checked": "false"}]'),('[{"name": "John", "checked": "false"}, {"name": "Lucy", "checked": "false"}]'),('[{"name": "John", "checked": "false"}, {"name": "Lucy", "checked": "true"}]');
select * from users, jsonb_array_elements(users.data) obj
where obj->>'name' = 'John' and obj->>'checked' = 'true';
data | value
-----------------------------------------------------------------------------+-------------------------------------
[{"name": "John", "checked": "true"}, {"name": "Lucy", "checked": "false"}] | {"name": "John", "checked": "true"}
(1 row)
I want to be able to access deeper elements stored in a json in the field json, stored in a postgresql database. For example, I would like to be able to access the elements that traverse the path states->events->time from the json provided below. Here is the postgreSQL query I'm using:
SELECT
data#>> '{userId}' as user,
data#>> '{region}' as region,
data#>>'{priorTimeSpentInApp}' as priotTimeSpentInApp,
data#>>'{userAttributes, "Total Friends"}' as totalFriends
from game_json
WHERE game_name LIKE 'myNewGame'
LIMIT 1000
and here is an example record from the json field
{
"region": "oh",
"deviceModel": "inHouseDevice",
"states": [
{
"events": [
{
"time": 1430247045.176,
"name": "Session Start",
"value": 0,
"parameters": {
"Balance": "40"
},
"info": ""
},
{
"time": 1430247293.501,
"name": "Mission1",
"value": 1,
"parameters": {
"Result": "Win ",
"Replay": "no",
"Attempt Number": "1"
},
"info": ""
}
]
}
],
"priorTimeSpentInApp": 28989.41467999999,
"country": "CA",
"city": "vancouver",
"isDeveloper": true,
"time": 1430247044.414,
"duration": 411.53,
"timezone": "America/Cleveland",
"priorSessions": 47,
"experiments": [],
"systemVersion": "3.8.1",
"appVersion": "14312",
"userId": "ef617d7ad4c6982e2cb7f6902801eb8a",
"isSession": true,
"firstRun": 1429572011.15,
"priorEvents": 69,
"userAttributes": {
"Total Friends": "0",
"Device Type": "Tablet",
"Social Connection": "None",
"Item Slots Owned": "12",
"Total Levels Played": "0",
"Retention Cohort": "Day 0",
"Player Progression": "0",
"Characters Owned": "1"
},
"deviceId": "ef617d7ad4c6982e2cb7f6902801eb8a"
}
That SQL query works, except that it doesn't give me any return values for totalFriends (e.g. data#>>'{userAttributes, "Total Friends"}' as totalFriends). I assume that part of the problem is that events falls within a square bracket (I don't know what that indicates in the json format) as opposed to a curly brace, but I'm also unable to extract values from the userAttributes key.
I would appreciate it if anyone could help me.
I'm sorry if this question has been asked elsewhere. I'm so new to postgresql and even json that I'm having trouble coming up with the proper terminology to find the answers to this (and related) questions.
You should definitely familiarize yourself with the basics of json
and json functions and operators in Postgres.
In the second source pay attention to the operators -> and ->>.
General rule: use -> to get a json object, ->> to get a json value as text.
Using these operators you can rewrite your query in the way which returns correct value of 'Total Friends':
select
data->>'userId' as user,
data->>'region' as region,
data->>'priorTimeSpentInApp' as priotTimeSpentInApp,
data->'userAttributes'->>'Total Friends' as totalFriends
from game_json
where game_name like 'myNewGame';
Json objects in square brackets are elements of a json array.
Json arrays may have many elements.
The elements are accessed by an index.
Json arrays are indexed from 0 (the first element of an array has an index 0).
Example:
select
data->'states'->0->'events'->1->>'name'
from game_json
where game_name like 'myNewGame';
-- returns "Mission1"
select
data->'states'->0->'events'->1->>'name'
from game_json
where game_name like 'myNewGame';
This did help me
I am learning elasticsearch and following along with the tutorial. I uploaded three documents into an index. When I supply the following query:
curl 'localhost:9200/vehicles/_search?query=driver.name:Jon'
I as expected get back object two and object three. However when I try querying using json:
curl localhost:9200/vehicles/_search -d'
{
"query":{
"prefix":{
"driver.name":"Jon"
}}}'
I get no results back. I am following the tutorial very closely, so I don't understand what the issue is. Any help would be really appreciated. The uploaded objects are below.
Thank you!
id:one
'{
"color": "green",
"driver": {
"born":"1989-09-12",
"name": "Ben"
},
"make": "BMW",
"model": "Aztek",
"value": 3000.0,
"year": 2003
}'
id:two
'{
"color": "black",
"driver": {
"born":"1934-09-08",
"name": "Jon"
},
"make": "Mercedes",
"model": "Benz",
"value": 10000.0,
"year": 2012
}'
id:three
'{
"color": "green",
"driver": {
"born":"1934-09-08",
"name": "Jon"
},
"make": "BMW",
"model": "Benz",
"value": 10000.0,
"year": 2012
}'
The prefix-query "matches documents that have fields containing terms with a specified prefix (not analyzed)".
Note the "not analyzed"-part. Lucene is looking for anything starting with "Jon" in the index, but the standard analyzer lowercases terms. That is, "jon" is in the index, but "Jon" is not.
Thus, if you lowercase the text in your prefix-query, it should work. Here is a runnable example: https://www.found.no/play/gist/7629456
Try:
curl -XGET "http://localhost:9200/vehicles/_search" -d '
{
"query": {"query_string" : { "query" : "driver.name:Jon" }}
}'
In any case, If you are new to elasticsearch I really recommend you read the documentation because there are lots of types of queries. Besides, the results of queries also depends on how you index the documents, how you define the mapping, etc.
In order to use the prefix query, you need to hit a non-analyzed field. In your mappings for driver.name, if you set "index" to "not_analyzed", you can use the prefix query. Otherwise, you should use a match query or something similar.