I have a postgresql table of cities (1 row = 1 city) with a jsonb colum containing the name of the city in different languages (as a list, not an array). For example for Paris(France) I have:
id_city (integer) = 7444
name_city (text) = Paris
names_i18n (jsonb) = {"name:fr":"Paris","name:zh":"巴黎","name:it":"Parigi",...}
In reality in my table I have around 20 different languages. So I try to find a city looking for any name:xx's value that could match a parameter given by the user, but I can't find how to query the jsonb column in that way. I've tried something like the request below but it doesn't seem to be the good syntaxe
select * from jsonb_each_text(select names_i18n from CityTable)
where value ilike 'Parigi'
I have also tried the following
select * from CityTable where names_i18n ? 'Parigi';
But it seems to work only for the key part of the jsonb, is there any similar operator for the value part? I also need a way to know what name:XX has been found, not only the city name.
Anyone has a clue?
with CityTable (id_city, name_city, names_i18n) as (values(
7444, 'Paris',
'{"name:fr":"Paris","name:zh":"巴黎","name:it":"Parigi"}'::jsonb
))
select *
from CityTable, jsonb_each_text(names_i18n) jbet (key, value)
where value ilike 'Parigi'
;
id_city | name_city | names_i18n | key | value
---------+-----------+--------------------------------------------------------------+---------+--------
7444 | Paris | {"name:fr": "Paris", "name:it": "Parigi", "name:zh": "巴黎"} | name:it | Parigi
Related
I currently have a query in PostgreSQL like:
SELECT
name
FROM
ingredients
WHERE
name = ANY({"string value",tomato,other})
My ingredients table is simply a list of names:
name
----------
jalapeno
tomatoes
avocados
lime
My issue is that plural values in the array will not match single values in the query. To solve this, I created a tsvector column on the table:
name | tokens
---------------+--------------
jalapeno | 'jalapeno':1
tomatoes | 'tomato':1
avocados | 'avocado':1
lime | 'lime':1
I'm able to correctly query single values from the table like this:
SELECT
name,
ts_rank_cd(tokens, plainto_tsquery('tomato'), 16) AS rank
FROM
ingredients
WHERE
tokens ## plainto_tsquery('tomato')
ORDER BY
rank DESC;
However, I need to query values from the entire array. The array is generated from another function, so I have control over the type of each of items in the array.
How can I use the ## operand with ANY(anyarray)?
That should be straight forward:
WHERE tokens ## ANY
(ARRAY[
plainto_tsquery('tomato'),
plainto_tsquery('celery'),
plainto_tsquery('vodka')
])
I have a table storing first names and surnames; some may be stored with capitalisation. Is there a query I could use to return only those rows with capitalisation?
For instance, if I have the following entries:
firstname | surname
-----------+-----------
Bob | Jones
john | bobbins
I'd only expect to be returned the record for "Bob Jones".
I'm sure it's not a difficult thing to do, but I haven't been able to find any examples anywhere.
Compare the value with the value where the first character is upper-case:
select *
from the_table
where firstname = initcap(firstname)
and surname = initcap(surname);
The function initcap() converts the first letter of each word to upper case and the rest to lower case.
A typical and relevant application of tsvectot is to query and summarize information about the set of occurred words and about its frequency... And JSONB is the natural choice (!) to represent tsvectot datatype for these "querying applications"... So,
There are a simple workaround to cast tsvector into JSONB?
Example: counting global frequency of words of a cached tsvectot's, will be something like this query
SELECT r.key as word, SUM(r.value) as occurrences
FROM (
SELECT jsonb_each(kx_tsvectot::jsonb) as r FROM terms
) t
GROUP BY 1;
You can use ts_stat() function, which will give you exactly what you need
word text — the value of a lexeme
ndoc integer — number of documents (tsvectors) the word occurred in
nentry integer — total number of occurrences of the word
Example may be the following:
CREATE TABLE t (
tsv TSVECTOR
);
INSERT INTO t VALUES
('word'::TSVECTOR),
('second word'::TSVECTOR),
('third word'::TSVECTOR);
SELECT * FROM
ts_stat('SELECT tsv FROM t');
Result:
word | ndoc | nentry
--------+------+--------
word | 3 | 3
third | 1 | 1
second | 1 | 1
(3 rows)
If you still want to convert it to jsonb you can use cast word from text to jsonb.
I want to search inside a full search column using certain letters, I mean:
select "Name","Country","_score" from datatable where match("Country", 'China');
Returns many rows and is ok. My question is, how can I search for example:
select "Name","Country","_score" from datatable where match("Country", 'Ch');
I want to see, China, Chile, etc.
I think that match_type phrase_prefix can be the answer, but I don't know how I can use (correct syntax).
The match predicate supports different types by use of using match_type [with (match_parameter = [value])].
So in your example using the phrase_prefix match type:
select "Name","Country","_score" from datatable where match("Country", 'Ch') using phrase_prefix;
gives you your desired results.
See the match predicate documentation: https://crate.io/docs/en/latest/sql/fulltext.html?#match-predicate
If you just need to match the beginning of a string column, you don't need a fulltext analyzed column. You can use the LIKE operator instead, e.g.:
cr> create table names_table (name string, country string);
CREATE OK (0.840 sec)
cr> insert into names_table (name, country) values ('foo', 'China'), ('bar','Chile'), ('foobar', 'Austria');
INSERT OK, 3 rows affected (0.049 sec)
cr> select * from names_table where country like 'Ch%';
+---------+------+
| country | name |
+---------+------+
| Chile | bar |
| China | foo |
+---------+------+
SELECT 2 rows in set (0.037 sec)
This is my table:
id | integer | not null default nextval('frontend_prescription_id_seq'::regclass)
actual_cost | double precision | not null
chemical_id | character varying(9) | not null
practice_id | character varying(6) | not null
I'd like to query results for a particular practice_id, and then sum the actual_cost by date and by the first two characters of the chemical_id. Is this possible in Postgres?
In other words, I'd like the output to look something like this:
processing_date | cost | chemical_id_substr
01-01-2010 1234 01
01-02-2010 4366 01
01-01-2010 3827 02
01-02-2010 8768 02
This is my current query, but it groups by the whole of chemical_id, not the substring:
query = "SELECT SUM(actual_cost) as cost, processing_date, "
query += "chemical_id as id FROM frontend_items"
query += " WHERE practice_id=%s "
query += "GROUP BY processing_date, chemical_id"
cursor.execute(query, (practice_id,))
I'm not sure how to change this to group by substring, or whether I should add a functional index, or whether I should just denormalise my table and add a new column. Thanks for any help.
You can do this, but you also need to make sure the substring is used in the select list, not the complete column:
SELECT SUM(actual_cost) as cost,
processing_date,
left(chemical_id,2) as id --<< use the same expression here as in the GROUP BY
FROM frontend_items
WHERE practice_id= %s
GROUP BY processing_date, left(chemical_id,2);