Recently started working on Postgres and need to pivot data.
I wrote the following query:
select *
from crosstab (
$$
with tmp_kv as (
select distinct pat_id
,col.name as key, replace(replace(replace(value, '[',''), ']', ''),'"','') as value
from (
select p.Id as pat_id, nullif(kv.key,'undefined')::int as key, trim(kv.value::text,'"') as value
from pat_table p
left join e_table e on e.pat_id = p.id and e.id is null
,jsonb_each_text(p.data) as kv
) t
left join lateral (
select name::text as name from public.config_fields fld
where id = t.key
) col on true
)
select pat_id, key, value
from tmp_kv
where nullif(trim(key),'') is not null
order by pat_id, key
$$,$$
select distinct key from tmp_kv -- (Get error "relation "tmp_kv" does not exist" )
where nullif(trim(key),'') is not null
order by 1
$$
) as (
pat_id bigint
...
...
);
Query works if I take the WITH clause out into temporary table. But will be deploying it to production with read replicas, so need it to be working with a CTE. Is there a way?
The two queries passed as strings to the crosstab() function are separate queries.
A CTE can only be attached to a single query.
What you ask for is strictly impossible.
Since you have to spell out the (static) return type for crosstab() anyway, and the result of the query in the 2nd parameter has to match that, it's pointless to use a query with a dynamic result as 2nd parameter to begin with.
Related
This is my trivial test table,
create table test (
id int not null generated always as identity,
first_name. varchar,
primary key (id),
unique(first_name)
);
As an alternative to insert-into-on-conflict sentences, I was trying to use the coalesce laziness to execute a select whenever possible or an insert, only when select fails to find a row.
coalesce laziness is described in documentation. See https://www.postgresql.org/docs/current/functions-conditional.html
Like a CASE expression, COALESCE only evaluates the arguments that are needed to determine the result; that is, arguments to the right of the first non-null argument are not evaluated. This SQL-standard function provides capabilities similar to NVL and IFNULL, which are used in some other database systems.
I also want to get back the id value of the row, having being inserted or not.
I started with:
select coalesce (
(select id from test where first_name='carlos'),
(insert into test(first_name) values('carlos') returning id)
);
but an error syntax error at or near "into" was found.
See it on this other DBFiddle
https://www.db-fiddle.com/f/t7TVkoLTtWU17iaTAbEhDe/0
Then I tried:
select coalesce (
(select id from test where first_name='carlos'),
(with r as (
insert into test(first_name) values('carlos') returning id
) select id from r
)
);
Here I am getting a WITH clause containing a data-modifying statement must be at the top level error that I don't understand, as insert is the first and only sentence within the with.
I am testing this with DBFiddle and PostgreSQL 13. The source code can be found at
https://www.db-fiddle.com/f/hp8T1iQ8eS4wozDCBhBXDw/5
Different method: chained CTEs:
CREATE TABLE test
( id INTEGER NOT NULL GENERATED ALWAYS AS IDENTITY PRIMARY KEY
, first_name VARCHAR UNIQUE
);
WITH sel AS (
SELECT id FROM test WHERE first_name = 'carlos'
)
, ins AS (
INSERT INTO test(first_name)
SELECT 'carlos'
WHERE NOT EXISTS (SELECT 1 FROM test WHERE first_name = 'carlos')
RETURNING id
)
, omg AS (
SELECT id FROM sel
UNION ALL
SELECT id FROM ins
)
SELECT id
FROM omg
;
It seems that the returning value from the insert into clause is not equivalent in nature to the scalar query of a select clause. So I try encapsulating the insert into into an SQL function and it worked.
create or replace function insert_first_name(
_first_name varchar
) returns int
language sql as $$
insert into test (first_name)
values (_first_name)
returning id;
$$;
select coalesce (
(select id from test where first_name='carlos'),
(select insert_first_name('carlos'))
);
See it on https://www.db-fiddle.com/f/73rVXgqGfrG4VmjrAk6Z3i/2
This is a refinement on #wildplasser accepted answer. it avoids comparing first_name twice and uses coalesce instead of union all. Kind of an selsert in just one sentence.
with sel as (
select id from test where first_name = 'carlos'
)
, ins as (
insert into test(first_name)
select 'carlos'
where (select id from sel) is null
returning id
)
select coalesce (
(select id from sel),
(select id from ins)
);
See it at https://www.db-fiddle.com/f/goRh4TyAebTkEZFHk6WbtK/6
I have the following query
SELECT DISTINCT ON (user_id) user_id, timestamp
FROM entries
WHERE user_id in (1,2)
AND entry_type IN(
SELECT jsonb_array_elements_text(
SELECT entry_types
FROM users INNER JOIN orgs
ON org_id = orgs.id
WHERE users.id = 1
)
);
I'm getting a syntax error at or near select
syntax error at or near "select" LINE 1: ... entry_type in( select
jsonb_array_elements_text(select ent.
The field entry_types is a JSONB field, so I am trying to convert it to text in order to use it in the WHERE IN clause.
PostgreSQL 13.0
This sub-query within jsonb_array_elements_text
SELECT entry_types
FROM users INNER JOIN orgs
ON org_id = orgs.id
WHERE users.id = 1
Returns a single JSONB entry like this:
entry_types
--------------------------------------------
["type1", "type2", "type3"]
I'm simply trying to use the array of text values returned there as the criteria inside the WHERE IN clause.
The syntax error seems to point somewhere else, so maybe I am wrong, but the problem I see is a missing pair of parentheses around the subquery:
jsonb_array_elements_text((SELECT ...))
I have a select query return and it shows the result like below:
select * from table gives the result like below
I have parameter called Apple If I pass the parameter somewhere in query I should get the result like below
How to get this in postgresql. If anyone knows please share the answer below.
I would do this with a helper function for clarity. And it might be reusable.
create or replace function filter_jsonb_array(arr jsonb, fruit text)
returns jsonb language sql immutable as
$$
select coalesce
(
(select jsonb_agg(j) from jsonb_array_elements(arr) j where j ->> 'fruit' = fruit),
'[]'::jsonb
);
$$;
and then
select "Column_A", "Column_B", filter_jsonb_array("Column_JSONARRAY", 'Apple') from table_;
If you do not want a function then the function body can be placed directly into the select query.
select
"Column_A",
"Column_B",
coalesce
(
(select jsonb_agg(j) from jsonb_array_elements("Column_JSONARRAY") j where j ->> 'fruit' = 'Apple'),
'[]'::jsonb
) "Column_JSONARRAY"
from table_;
Considering your datatype of column Column_JSONARRAY is JSONB, try This:
with cte as (
SELECT column_a, column_b, (column_jsonarray ->> ( index_-1 )::int)::jsonb AS "column_jsonarray"
FROM table_
CROSS JOIN jsonb_array_elements(column_jsonarray)
WITH ORDINALITY arr(array_,index_)
WHERE array_->>'fruit' in ('Apple')
)
select t1.column_a, t1.column_b, jsonb_agg(t2.column_jsonarray)
from table_ t1
left join cte t2 on t1.column_a =t2.column_a and t1.column_b =t2.column_b
group by t1.column_a, t1.column_b
I have to compare the values of multiple columns which includes character, integer, and date types columns from 2 tables.
I have used the following type of SQL ( actual SQL have 100+ column each side of DISTINCT FROM ).
SELECT table1.* from
Table1 JOIN table2 ON ( table1.id = table2.id )
WHERE
( table1.name, table1.email, table1.dob, table1.application_id )
IS DISTINCT FROM
( table2.name, table2.email, table2.dob, table2.application_id );
if email id/name has case difference then it is considering them distinct.
using LOWER() can solve the problem but that I need to write for each text column. Can I do this in any other way?
I have simple table valued function returning one column table
ALTER FUNCTION [dbo].[fnGetProducersByWheelType]
(
#wheeltype int
)
RETURNS TABLE
AS
RETURN
(
SELECT ProducerId
FROM ProducersByWheelTypes
WHERE WheelType=#wheeltype
)
and what i need is to know if i can call the way like :
select *
from producers
where producerid in ( fnGetProducersByWheelType(2))
not
select *
from producers
where producerid in (
select productId
from fnGetProducersByWheelType(2)
)
i.e. not mention single column productId 'select productId from'
No. As the documentation for in shows you may have either a subquery or list of expressions. A TVF is not an expression.
You can do INNER JOIN instead:
select p.*
from producers p
join fnGetProducersByWheelType(2) f
on p.producerid = f.producerid