I am trying to use Postgresql Full Text Search. I read that the stop words (words ignored for indexing) are implemented via dictionary. But I would like to give the user a limited control over the stop words (insert new ones), so I grouped then in a table.
From the example below:
select strip(to_tsvector('simple', texto)) from longtxts where id = 23;
I can get the vector:
{'alta' 'aluno' 'cada' 'do' 'em' 'leia' 'livro' 'pedir' 'que' 'trecho' 'um' 'voz'}
And now I would like to remove the elements from the stopwords table:
select array(select palavra_proibida from stopwords);
That returns the array:
{a,as,ao,aos,com,default,e,eu,o,os,da,das,de,do,dos,em,lhe,na,nao,nas,no,nos,ou,por,para,pra,que,sem,se,um,uma}
Then, following documentation:
ts_delete(vector tsvector, lexemes text[]) tsvector remove any occurrence of lexemes in lexemes from vector ts_delete('fat:2,4 cat:3 rat:5A'::tsvector, ARRAY['fat','rat'])
I tried a lot. For example:
select ts_delete((select strip(to_tsvector('simple', texto)) from longtxts where id = 23), array[(select palavra_proibida from stopwords)]);
But I always receive the error:
ERROR: function ts_delete(tsvector, character varying[]) does not exist
LINE 1: select ts_delete((select strip(to_tsvector('simple', texto))...
^
HINT: No function matches the given name and argument types. You might need to add explicit type casts.
Could anyone help me? Thanks in advance!
ts_delete was introduced in PostgreSQL 9.6. Based on the error message, you're using an earlier version. You may try select version(); to be sure.
When you land on the PostgreSQL online documentation with a web search, it may correspond to any version. The version is in the URL and there's a "This page in another version" set of links at the top of each page to help switching to the equivalent doc for a different version.
Related
So in short:
I need to find all rows in the column Translation that begin with the letter M (M123 is one of the Prefixes) and then I need to remove the M123 and similar prefixes from all the rows.
For example, row 1 contains the following data:
M123 - This is translated from Spanish to English
And I need to remove the M123 - from the mentioned data. And this I need to do for the Translation column in every row in the table.
It's been a while since I actually did some SQL-Queries. So I tried a WHERE clause to find all the M prefixes but my query returns an empty search. Following is the query I am using atm:
SELECT Translation from Translation_Table where Translation like 'M';
I am a little bit confused right now. So any help is appreciated.
I sense that you might be wanting to do an update here, rather than a select:
UPDATE Translation_Table
SET Translation = REGEXP_REPLACE(Translation, 'M[0-9]+', '')
WHERE Translation ~ '^M[0-9]+';
addition to this answer following query will remove all occurence of M[any length of a number]
UPDATE Translation_Table
SET Translation = REGEXP_REPLACE(Translation, '[M[:digit:]]', '', 'g')
WHERE Translation ~ '.M[0-9]*';
Please does anyone know why this:
SELECT to_tsvector('an');
returns nothing but
SELECT to_tsvector('nn');
or
SELECT to_tsvector('n');
or
SELECT to_tsvector('aa');
do?
I am testing this on PostgreSQL 13 running on SUPABASE.
Thanks
Because "an" is a stop word in your current setup (probably English, the default).
From the documentation
The to_tsvector function internally calls a parser which breaks the document text into tokens and assigns a type to each token. For each token, a list of dictionaries (Section 12.6) is consulted, where the list can vary depending on the token type.
And (emphasis mine)...
Some words are recognized as stop words (Section 12.6.1), which causes them to be ignored since they occur too frequently to be useful in searching.
I need to be able to use variables in table names - I basically have the same set of tables used for different types of data, so I would like to just have one dashboard and swapping between all types instead of always having to set up multiple identical dashboards.
My query is something like:
select * from table_$variable_name;
Where my list of possible variable is something like cat, dog, bird
I can seem to make this work, if I only put the variable as shown above I get the following error
Error 1146: Table 'table_$variable_name' doesn't exist
If I enclose it in curly brackets, I get this error instead.
Error 1064: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '{bird}' at line 1
(i.e. with the selected variable actually being visible this time)
I'm not sure if the issue is having underscores in the table names, I tried putting underscores around my variables too to check and I had no luck with that.
Another thing I tried was gradually adding on to the table name, so e.g.
select * from table_$variable;
Still returns an error, but I can see the table name starting to form correctly
Error 1146: Table 'table_bird_' doesn't exist
However, as soon as I add another underscore, the variable is not picked up abymore
```Error 1146: Table 'table_$variable_' doesn't exist``
I'm sure it's something silly I am missing in the syntax of the query - anyone has any suggestions?
Using this https://grafana.com/docs/grafana/latest/variables/templates-and-variables/ for reference
As #arturomp suggests, use
${var:raw}
At least in my case, this was the solution that worked.
I found double square brackets work. e.g.
Rather than
select * from table_$variable_name;
use
select * from table_[[variable_name]];
I'm trying to work out how to expand a JSONB field with a jsonb_to_recordset and a custom type.
Postgres 11.4.
This is just a test case, but for the minute I'm trying to work out the syntax. I've got a table named data_file_info with a JSONB field named table_stats. The JSONB field always includes a JSON array with the same structure:
[
{"table_name":"Activity","record_count":0,"table_number":214},
{"table_name":"Assembly","record_count":1,"table_number":15},
{"table_name":"AssemblyProds","record_count":0,"table_number":154}
]
The following code works correctly:
from data_file_info,
jsonb_to_recordset(table_stats) as table_stats_splat (
table_name text,
record_count integer,
table_number integer
)
What I would like to do is pass in a custm type definition instead of the long-form column definition list shown above. Here's the matching type:
create type data.table_stats_type as (
table_name text,
record_count integer,
table_number integer)
Some examples I've seen, and the docs say, that you can supply a type name using a null:row_type casting in the first parameter to jsonb_to_recordset. The examples that I've found use in-line JSON, while I'm trying to pull stored JSON. I've made a few attempts, all have failed. Below are two of the trials, with errors. Can someone point me towards the correct syntax?
FAIL:
select table_stats_splat.*
from data_file_info,
jsonb_populate_recordset(null::table_stats_type, data_file_info) as table_stats_splat;
-- ERROR: function jsonb_populate_recordset(table_stats_type, data_file_info) does not exist
-- LINE 4: jsonb_populate_recordset(null::table_stats_type, dat...
^
-- HINT: No function matches the given name and argument types. You might need to add explicit type casts. (Line 4)
FAIL:
select *
from jsonb_populate_recordset(NULL::table_stats_type, (select table_stats from data_file_info)) as table_stats_splat;
-- ERROR: more than one row returned by a subquery used as an expression. (Line 2)
I'm doubtlessly missing something pretty obvious, and am hoping someone can suggest what that is.
Use the column as the second parameter:
select table_stats_splat.*
from data_file_info,
jsonb_populate_recordset(null::table_stats_type, table_stats) as table_stats_splat;
I'm using full text search supported by postgres, I installed acts_as_tsearch plugin and it works successfully, but when I tried it later I found an error
runtimeError: ERROR C42883 Mfunction ts_rank_cd(text, tsquery) does
not exist HNo function matches the given name and argument types. You
might need to add explicit type
You need to cast your first parameter into a tsvector.
So let's assume you're searching against a column named foo.text. You will want to change from this:
SELECT ts_rank_cd(foo.text, plainto_tsquery('my search terms')) FROM foo;
to this:
SELECT ts_rank_cd(to_tsvector(foo.text), plainto_tsquery('my search terms')) FROM foo;
or something similar.
If you're using the ## operator elsewhere, you can generally re-use the expressions that operator is operating on.
You can find more documentation on to_tsvector at http://www.postgresql.org/docs/current/static/textsearch-controls.html#TEXTSEARCH-PARSING-DOCUMENTS
EDIT
ts_rank_cd(text, tsquery) does not
exist
This means there is no function with this name that accepts text and a tsquery parameter as input. And that's correct, PostgreSQL doens't have a function using these parameters.
From the manual:
ts_rank_cd([ weights float4[], ]
vector tsvector, query tsquery [,
normalization integer ])
Change your input for the function ts_rank_cd() and you will be fine.