I am storing some ids and names in a jsonb array of object like this
[{"id":"1","name":"abc"},{"id":"2","name":"cde"}]
My table looks like this
id userinfo
1 [{"id":"1","name":"abc"},{"id":"2","name":"cde"}]
2 [{"id":"3","name":"fgh"},{"id":"4","name":"ijk"}]
I am trying to select all the records with id 1 but I just want to get ids in userinfo object I don't want names
I tried this
select distinct userinfo->'name' from table where id = 1
but this is giving me null value
This will work with this query
select distinct userinfo->0->'name' from table where id = 1
but I don't know the index so how can I use this query to get my desired result
Thanks
You need to normalize the data by unnesting the array, then you can access each element.
select ui.info ->> 'id' as id,
ui.info ->> 'name' as name
from the_table t
cross join lateral jsonb_array_elements(t.userinfo) as ui(info)
where t.id = 1;
Online example: http://rextester.com/FCNM11312
Related
I have a database schema like the following where I have a Children record table
CREATE TABLE Children (
name varchar(100),
friends JSON NOT NULL,
);
INSERT INTO Children (name,friends)
VALUES('Sam',
array['{"name":"Rakesh","country":"Africa"}',
'{"name":"Ramesh","country":"India"}']::json[]);
Now I need to query the data and display it only if the name of the friend is like '%Ra'. Structure of the JSON data is consistent.
If you have json[] as data type then you can use unnest and then write your query, or if it is json then you can use json_array_elements.
Below code considers json[] data type -
select * from Children
where name in (
select name from (
select name, unnest(friends) as friend from Children
) i
where i.friend->>'name' like '%Ra');
DBFiddle
In Google BigQuery, I would like to delete a subset of records, based on the value of a specific column. It's a query that I need to run repeatedly and that I would like to run automatically.
The problem is that this specific column is of the form STRUCT<column_1 ARRAY (STRING), column_2 ARRAY (STRING), ... >, and I don't know how to use such a column in the where-clause when using the delete-command.
Here is basically what I am trying to do (this code does not work):
DELETE
FROM dataset.table t
LEFT JOIN UNNEST(t.category.column_1) AS type
WHERE t.partition_date = '2020-07-22'
AND type = 'some_value'
The error that I'm getting is: Syntax error: Expected end of input but got keyword LEFT at [3:1]
If I replace the DELETE with SELECT *, it does work:
SELECT *
FROM dataset.table t
LEFT JOIN UNNEST(t.category.column_1) AS type
WHERE t.partition_date = '2020-07-22'
AND type = 'some_value'
Does somebody know how to use such a column to delete a subset of records?
EDIT:
Here is some code to create a reproducible example with some silly data (fill in your own dataset and table name in all queries):
Suppose you want to delete all rows where category.type contains the value 'food'.
1 - create a table:
CREATE TABLE <DATASET>.<TABLE_NAME>
(
article STRING,
category STRUCT<
color STRING,
type ARRAY<STRING>
>
);
2 - Insert data into the new table:
INSERT <DATASET>.<TABLE_NAME>
SELECT "apple" AS article, STRUCT('red' AS color, ['fruit','food'] as type) AS category
UNION ALL
SELECT "cabbage" AS article, STRUCT('blue' AS color, ['vegetable', 'food'] as type) AS category
UNION ALL
SELECT "book" AS article, STRUCT('red' AS color, ['object'] as type) AS category
UNION ALL
SELECT "dog" AS article, STRUCT('green' AS color, ['animal', 'pet'] as type) AS category;
3 - Show that select works (return all rows where category.type contains the value 'food'; these are the rows I want to delete):
SELECT *
FROM <DATASET>.<TABLE_NAME>
LEFT JOIN UNNEST(category.type) type
WHERE type = 'food'
Initial Result
4 - My attempt at deleting rows where category.type contains 'food' does not work:
DELETE
FROM <DATASET>.<TABLE_NAME>
LEFT JOIN UNNEST(category.type) type
WHERE type = 'food'
Syntax error: Unexpected keyword LEFT at [3:1]
Desired Result
This is the code I used to delete the desired records (the records where category.type contains the value 'food'.)
DELETE
FROM <DATASET>.<TABLE_NAME> t1
WHERE EXISTS(SELECT 1 FROM UNNEST(t1.category.type) t2 WHERE t2 = 'food')
The embarrasing thing is that I've seen these kind of answers on similar questions (for example on update-queries). But I come from Oracle-SQL and I think that there you are required to connect your subquery with your main query in the WHERE-statement of the subquery (ie. connect t1 with t2), so I didn't understand these answers. That's why I posted this question.
However, I learned that BigQuery automatically understands how to connect table t1 and 'table' t2; you don't have to explicitly connect them.
Now it is possible to still do this (perhaps even recommended?):
DELETE
FROM <DATASET>.<TABLE_NAME> t1
WHERE EXISTS (SELECT 1 FROM <DATASET>.<TABLE_NAME> t2 LEFT JOIN UNNEST(t2.category.type) AS type WHERE type = 'food' AND t1.article=t2.article)
but a second difficulty for me was that my ID in my actual data is somehow hidden in an array>struct-construction, so I got stuck connecting t1 & t2. Fortunately this is not always an absolute necessity.
Since you did not provide any sample data I am going to explain using some dummy data. In case you add your sample data, I can update the answer.
Firstly,according to your description, you have only a STRUCT not an Array[Struct <col_1, col_2>].For this reason, you do not need to use UNNEST to access the values within the data. Below is an example how to access particular data within a STRUCT.
WITH data AS (
SELECT 1 AS id, STRUCT("Alex" AS name, 30 AS age, "NYC" AS city) AS info UNION ALL
SELECT 1 AS id, STRUCT("Leo" AS name, 18 AS age, "Sydney" AS city) AS info UNION ALL
SELECT 1 AS id, STRUCT("Robert" AS name, 25 AS age, "Paris" AS city) AS info UNION ALL
SELECT 1 AS id, STRUCT("Mary" AS name, 28 AS age, "London" AS city) AS info UNION ALL
SELECT 1 AS id, STRUCT("Ralph" AS name, 45 AS age, "London" AS city) AS info
)
SELECT * FROM data
WHERE info.city = "London"
Notice that the STRUCT is named info and the data we accessed is city and used it in the WHERE clause.
Now, in order to delete the rows that contains an specific value within the STRUCT , in your case I assume it would be your_struct.column_1, you can use DELETE or MERGE and DELETE. I have saved the above data in a table to execute the below examples, which have the same output,
First method: DELETE
DELETE FROM `project.dataset.table`
WHERE info.city = "Sydney"
Second method: MERGE and DELETE
MERGE `project.dataset.table` a
USING (SELECT * from `project.dataset.table` WHERE info.city ="London") b
ON a.info.city =b.info.city
WHEN matched and b.id=1 then
Delete
And the output for both queries,
Row id info.name info.age info.city
1 1 Alex 30 NYC
2 1 Robert 25 Paris
3 1 Ralph 45 London
4 1 Mary 28 London
As you can see the row where info.city = "Sydney" was deleted in both cases.
It is important to point out that your data is excluded from your source table. Therefore, you should be careful.
Note: Since you want to run this process everyday, you could use Schedule Query within BigQuery Console, appending or overwriting the results after each run. Also, it is a good practice not deleting data from your source table. Thus, consider creating a new table from your source table without the rows you do not desire.
PostgreSQL version: 10.3
Schema of product
id integer
data text
Schema of color
id integer
name text
Color of a product is stored within data as array of colorids ex: ['1','2'].
I need a query wherein I could get the color id and name for a particular product.
Tried something like this and got error:
select id,name from colors where id in (select trim(data::json ->> 'color_ids','[]') from products where id = 1);
ERROR: operator does not exist: integer = text
I tried this:
query:
select data::json ->> 'color_ids' from products where id = 1;
result:
["2","5","6","14"]
query:
select trim(data::json ->> 'color_ids','[]') from products where id = 1;
result:
"2","5","6","14"
I would also suggest making it a integer (int). Does it work when you put a replace around it?
replace (trim(data::json ->> 'color_ids','[]'), '"', '')
I am using postgres and have 2 tables, deviceTble has the following columns: deviceName, device_id, type, deviceOwnerPerson_id, deviceAccessPerson_id.
The other table is Person_kv and has 2 columns id,data (containing person info but in JSON format).
I want to a select query from deviceTble and want to use first_name and last_name of a person which are in Person_kv table by given of deviceOwnerPersonId and deviceAccessPersonId.
Here is what I have to get data from person_kv table to get data in tabular form:
select data :: json ->> 'id' as id
, data :: json ->> 'name' as first_name
, data :: json ->> 'surename' as last_name
from Person_kv
and expected deviceTble query:
select deviceName,device_id,type from deviceTble
I am confused either I use WITH clause on person_kv query and then join here or one by one on deviceOwnerPerson_id and deviceAccessPerson_id OR is there any other way as well by using inner query
Can someone tell me how I can get required result?
from you description you can just join em:
select deviceName,device_id,type, p.data:: json ->>'name' , p.data:: json ->>'surname'
from deviceTble d
join Person_kv p on p.data:: json ->>'id' = deviceOwnerPerson_id::text OR p.data:: json ->>'id' = deviceAccessPerson_id::text
I have a table named Text_Field which consists of a column named ID,
I have another table named Content which consists of a table named value,
I want to fetch those values of ID from the Text_Field table which are present in the value column of the Content and satisfying a said condition.
I know I can construct a query like this
SELECT ID
FROM Text_Field
WHERE ID IN (
SELECT value
FROM CONTENT
WHERE USER='CURRENT_USER')
My only problem is that for some scenarios the value table might contain the ID inside a string
So the inner query might return something like
56789
12334
12348
Rtf(833405)
Now if my ID is 833405 it is present in the value column but the IN query would return false,
I tried
group_concat(value)
So that the inner query returns a single row which is a string,
56789,12334,12348,Rtf(833405)
I want to know that after group_concat can I use something as LIKE to satisfy my need
Or is there some other way I can do this?
Use exists instead, with like:
SELECT t.ID
FROM Text_Field t
WHERE EXISTS (SELECT 1
FROM CONTENT c
WHERE c.USER = 'CURRENT_USER' AND
(c.value = t.id OR
c.value LIKE '%(' || t.id || ')%'
)
);
Note: