i have a field with value like below:
utf8: "\xE2\x9C\x93"
id: "805265"
plan: initial
acc: "123456"
last: "1234"
doc: "1281468479"
validation: field
commit: Accept
i used below query to extract acc value
select SUBSTRING_INDEX(SUBSTRING_INDEX(columnname, 'acc: "', -1),'last',1) as acc from table_name;
i am able to retrieve acc value but problem is when i export the result to csv file, the field is taking newline space which is before last...how do i get rid of that space???
I would expect you would want to strip out the end quote as well. But to answer your specific question, you can just update your SUBSTRING_INDEX delimiter to include the newline, i.e. select SUBSTRING_INDEX(SUBSTRING_INDEX(columnname, 'acc: "', -1),'\nlast',1) as acc from table_name;.
Or, if you prefer, you can use the REPLACE function to strip out any unwanted characters.
Related
Here is my string column with value for ex:
Customer: check, ID: 3963f4bb-59fb-4a26, NAME: TAMIL
I want only the value of "3963f4bb-59fb-4a26" which is in between start of "ID: "
and end keyword of ", ".
Please anyone suggest how to extract only that ID value.
The length of string may not be same and values inside may in mixed format also, so based on ID I wants to extract that string.
I tried using substring, but not able to extract result.
You can do it using SUBSTRING_INDEX :
select description, SUBSTRING_INDEX(SUBSTRING_INDEX(description, 'ID:', -1), ',', 1) as snippet
from my_table;
Check it here : https://dbfiddle.uk/K5FNq-EY
In my sql code, I receive a input string as a regular match's filter, I want to have the whole string as a normal string, even it includes some special characters.
Just look below:
do $$ declare
jdata jsonb='[{"name":"Dog 3*240+1*120"}]'::jsonb;
vfilter1 text='dog';
vfilter2 text='3*240+1*120';
vexists bool=false;
begin
select jdata #? concat('$[*] ? (#.name like_regex "',vfilter1,'" flag "i")')::jsonpath into vexists;
raise notice 'exists:%',vexists; --the result is true
select jdata #? concat('$[*] ? (#.name like_regex "',vfilter2,'" flag "i")')::jsonpath into vexists;
raise notice 'exists:%',vexists;-- the result is false
end;
$$ language plpgsql;
the string 3*240+1*120 include + and * characters, perhaps this causes the regular match have them as special character. In my code, I just want to have the whole vfilter string includes all special characters together as a normal string for the regular match.
What should I do?
You should read the documentation for the feature you are using.
The optional flag string may include one or more of the characters i
for case-insensitive match, m to allow ^ and $ to match at newlines, s
to allow . to match a newline, and q to quote the whole pattern
(reducing the behavior to a simple substring match).
I need to clean JSON data that could look like:
{
"reference":"0000010-CAJ",
"product_code":"00000-10",
"var_name":"CAJ-1",
"doc_date":"2020-02-09T21:01:01-05:00",
"due_date":"2020-03-10T21:01:01-05:00",
}
However, this is just one of many other possibilities (is for a log aggregation that gets data from many sources).
I need to replace "-" with "_", but without break the dates like "2020-03-10T21:01:01-05:00", so can't simply cast to string and do a replace. I wonder if exist an equivalent of:
for (k,v) in json:
if is_text(v):
v = replace(...)
You can check with a regex if the value looks like a timestamp:
update the_table
set the_column = (select
jsonb_object_agg(
key,
case
when value ~ '^[0-9]{4}-[0-9]{2}-[0-9]{2}T[0-9]{2}:[0-9]{2}:[0-9]{2}.*' then value
else replace(value, '-', '_')
end)
from jsonb_each_text(the_column) as t(key, value))
This iterates over all key/value pairs in the JSON column (using jsonb_each_text()) and assembles all of them back into a JSON again (using jsonb_object_agg()). Values that look like a timestamp are left unchanged, for all others, the - is replaced with a _.
First week having to deal with a MYSQL database and JSON field types and I cannot seem to figure out why values are encoded automatically and then returned in encoded format.
Given the following SQL
-- create a multiline string with a tab example
SET #str ="Line One
Line 2 Tabbed out
Line 3";
-- encode it
SET #j = JSON_OBJECT("str", #str);
-- extract the value by name
SET #strOut = JSON_EXTRACT(#J, "$.str");
-- show the object and attribute value.
SELECT #j, #strOut;
You end up with what appears to be a full formed JSON object with a single attribute encoded.
#j = {"str": "Line One\n\tLine 2\tTabbed out\n\tLine 3"}
but using JSON_EXTRACT to get the attribute value I get the encoded version including outer quotes.
#strOut = "Line One\n\tLine 2\tTabbed out\n\tLine 3"
I would expect to get my original string with the \n \t all unescaped to the original values and no outer quotes. as such
Line One
Line 2 Tabbed out
Line 3
I can't seem to find any JSON_DECODE or JSON_UNESCAPE or similar functions.
I did find a JSON_ESCAPE() function but that appears to be used to manually build a JSON object structure in a string.
What am I missing to extract the values to the original format?
I like to use handy operator ->> for this.
It was introduced in MySQL 5.7.13, and basically combines JSON_EXTRACT() and JSON_UNQUOTE():
SET #strOut = #J ->> '$.str';
You are looking for the JSON_UNQUOTE function
SET #strOut = JSON_UNQUOTE( JSON_EXTRACT(#J, "$.str") );
The result of JSON_EXTRACT() is intentionally a JSON document, not a string.
A JSON document may be:
An object enclosed in { }
An array enclosed in [ ]
A scalar string value enclosed in " "
A scalar number or boolean value
A null — but this is not an SQL NULL, it's a JSON null. This leads to confusing cases because you can extract a JSON field whose JSON value is null, and yet in an SQL expression, this fails IS NULL tests, and it also fails to be equal to an SQL string 'null'. Because it's a JSON type, not a scalar type.
Try to read this the json OV-fiets (http://fiets.openov.nl/locaties.json) in a postgres database with json_array_elements. Some names of train station contains the character ' .
Example ..... "description": "Helmond 't Hout"
I believe that my script fails because of the ' between Helmond and the t.
The script i use:
WITH data AS (SELECT 'paste the json from http://fiets.openov.nl/locaties.json'::json AS fc)
SELECT
row_number() OVER () AS gid,
feat->'locaties' AS locaties,
FROM (
SELECT json_array_elements(fc->'locaties') AS feat
FROM data
) AS f;*
++++++++++++++++++++++++++++++
The error i get:
*syntax error at or near "Hout"
LINE 3: ...Images": [], "name": "HMH - OV-fiets - Helmond 't Hout", "ex.*
How can i change the script to avoid the syntax error due to the character '
the easiest workaround here would probably be dollar quotes:
SELECT $dq$paste the json from http://fiets.openov.nl/locaties.json$dq$::json
In SQL, single quotes need to be escaped by doubling them, e.g.:
select 'Arthur''s house';
As an alternative (in Postgres) you can use dollar quoting to avoid changing the string:
SELECT $data$Arthur's house$data$