data is jsonb type
this query work
select id, modified_at, data,states from order where data->'id' = '2100000044078'
nice
but this not work
select id, modified_at, data,states from shop_order where data->'id' = '0000000000000'
error:
LINE 2: ..., data,states from order where data->'id' = '000000000...
^
DETAIL: Token "0000000000000" is invalid.
CONTEXT: JSON data, line 1: 0000000000000
SQL state: 22P02
Character: 161
-> returns a jsonb value, but you are trying to compare that with a text column. So Postgres tries to convert the value on the right hand side to jsonb.
Use the ->> operator instead which returns the value as text
where data->>'id' = '0000000000000'
Related
Let's suppose I have a table my_table with a field named data, of type jsonb, which thus contains a json data structure.
let's suppose that if I run
select id, data from my_table where id=10;
I get
id | data
------------------------------------------------------------------------------------------
10 | {
|"key_1": "value_1" ,
|"key_2": ["value_list_element_1", "value_list_element_2", "value_list_element_3" ],
|"key_3": {
| "key_3_1": "value_3_1",
| "key_3_2": {"key_3_2_1": "value_3_2_1", "key_3_2_2": "value_3_2_2"},
| "key_3_3": "value_3_3"
| }
| }
so in pretty formatting, the content of column data is
{
"key_1": "value_1",
"key_2": [
"value_list_element_1",
"value_list_element_2",
"value_list_element_3"
],
"key_3": {
"key_3_1": "value_3_1",
"key_3_2": {
"key_3_2_1": "value_3_2_1",
"key_3_2_2": "value_3_2_2"
},
"key_3_3": "value_3_3"
}
}
I know that If I want to get directly in a column the value of a key (of "level 1") of the json, I can do it with the ->> operator.
For example, if I want to get the value of key_2, what I do is
select id, data->>'key_2' alias_for_key_2 from my_table where id=10;
which returns
id | alias_for_key_2
------------------------------------------------------------------------------------------
10 |["value_list_element_1", "value_list_element_2", "value_list_element_3" ]
Now let's suppose I want to get the value of key_3_2_1, that is value_3_2_1.
How can I do it?
I have tryed with
select id, data->>'key_3'->>'key_3_2'->>'key_3_2_1' alias_for_key_3_2_1 from my_table where id=10;
but I get
select id, data->>'key_3'->>'key_3_2'->>'key_3_2_1' alias_for_key_3_2_1 from my_table where id=10;
^
HINT: No operators found with name and argument types provided. Types may need to be converted explicitly.
what am I doing wrong?
The problem in the query
select id, data->>'key_3'->>'key_3_2'->>'key_3_2_1' alias_for_key_3_2_1 --this is wrong!
from my_table
where id=10;
was that by using the ->> operand I was turning a json to a string, so that with the next ->> operand I was trying to get a json key object key_3_2 out of a string object, which makes no sense.
Thus one has to use the -> operand, which does not convert json into string, until one gets to the "final" key.
so the query I was looking for was
select id, data->'key_3'->'key_3_2'->>'key_3_2_1' alias_for_key_3_2_1 --final ->> : this gets the value of 'key_3_2_1' as string
from my_table
where id=10;
or either
select id, data->'key_3'->'key_3_2'->'key_3_2_1' alias_for_key_3_2_1 --final -> : this gets the value of 'key_3_2_1' as json / jsonb
from my_table
where id=10;
More info on JSON Functions and Operators can be find here
My situation is the following
-> The table A has a column named informations whose type is text
-> Inside the informations column is stored a JSON string (but is still a string), like this:
{
"key": "value",
"meta": {
"inner_key": "inner_value"
}
}
I'm trying to query this table by seraching its informations.meta.inner_key column with the given query:
SELECT * FROM A WHERE (informations::json#>>'{meta, inner_key}' = 'inner_value')
But I'm getting the following error:
ERROR: invalid input syntax for type json
DETAIL: The input string ended unexpectedly.
CONTEXT: JSON data, line 1:
SQL state: 22P02
I've built the query following the given link: DevHints - PostgreSQL
Does anyone know how to properly build the query ?
EDIT 1:
I solved with this workaround, but I think there are better solutions to the problem
WITH temporary_table as (SELECT A.informations::json#>>'{meta, inner_key}' as inner_key FROM A)
SELECT * FROM temporary_table WHERE inner_key = 'inner_value'
I have a Trip table in PostgreSQL DB, there is a column called meta in the table.
A example of meta in one row looks like:
meta = {"runTime": 3922000, "distance": 85132, "duration": 4049000, "fuelUsed": 19.595927498516176}
To select the trip which has largest value divided by "distance" and "runTime", I run query:
select MAX(tp."meta"->>'distance'/tp."meta"->>'runTime') maxkph FROM "Trip" tp
but I get ERROR:
/* ERROR: operator does not exist: unknown / jsonb LINE 1: MAX(tp."meta"->>'distance'/tp."meta"...
I also tried:
select MAX((tp."meta"->>'distance')/(tp."meta"->>'runTime')) maxkph FROM "Trip" tp
but get another ERROR:
/* ERROR: operator does not exist: text / text LINE 1: ...MAX((tp."meta"->>'distance')/(tp."meta...
Could you please help me to solve this problem?
There is not operator div for jsonb values. You have to cast a values on both sizes to some numeric type first:
MAX( ((tp."meta"->>'distance')::numeric) / ((tp."meta"->>'runTime')::numeric) ) maxkph
Try using parentheses:
MAX( (tp."meta"->>'distance') / (tp."meta"->>'runTime') ) as maxkph
Your second problem suggests that these values are stored as strings. So convert them:
MAX( (tp."meta"->>'distance')::numeric / (tp."meta"->>'runTime')::numeric ) as maxkph
I have a table that one of the columns is in type TEXT and holds a json object inside.
I what to reach a key inside that json and ask about it's value.
The column name is json_representation and the json looks like that:
{
"additionalInfo": {
"dbSources": [{
"user": "Mike"
}]
}
}
I want to get the value of the "user" and ask if it is equal to "Mike".
I tried the following:
select
json_representation->'additionalInfo'->'dbSources'->>'user' as singleUser
from users
where singleUser = 'Mike';
I keep getting an error:
Query execution failed
Reason:
SQL Error [42883]: ERROR: operator does not exist: text -> unknown
Hint: No operator matches the given name and argument type(s). You might need to add explicit type casts.
Position: 31
please advice
Thanks
The error message tells you what to do: you might need to add an explicit type cast:
And as you can not reference a column alias in the WHERE clause, you need to wrap it into a derived table:
select *
from (
select json_representation::json ->'additionalInfo'->'dbSources' -> 0 ->>'user' as single_user
from users
) as t
where t.single_user = 'Mike';
:: is Postgres' cast operator
But the better solution would be to change the column's data type to json permanently. And once you upgrade to a supported version of Postgres, you should use jsonb.
I got this error.
ERROR: column "name" does not exist LINE 6:
SELECT JS, location, location->>Name
^ SQL state: 42703 Character: 278
from this query
WITH JsonTable AS
(
SELECT
'[
{
"Id":1,
"Name":"A01",
"Address":"aaa",
"SearchVector":null,
"ParentLocationId":null
},
{
"Id":4,
"Name":"B-01",
"Address":"bbb",
"SearchVector":null,
"ParentLocationId":null
}
]'::jsonb AS JS
)
SELECT JS, location, location->>Name
FROM JsonTable, jsonb_array_elements(JS) x (location)
How can I select JSON value?
You are missing quotes around the name of the JSON attribute that you want to select. Just like object keys must always be quoted when the JSON object is declared, they need to be quoted when they are accessed.
See the Postgres documentation for the JSON datatype and JSON Functions and Operators.
You would need to change this:
SELECT JS, location, location->>Name
To:
SELECT JS, location, location->>'Name'
Demo on DB Fiddle.