SQL从SQL列中提取数据

Question

I have SQL table JSON data into one of the columns. The column type is varchar max. I have to extract the data from that column using sql. For example

{"RESPONSE":{"value":"<p>this is a test.....</p>","isAnswered":true}}'  

I want to extract: this is a test.....
and get rid of all attributes and Nodes
I am very new to JSON. Fisrt time looking into it and lost

Answer 1

You can try this:

begin transaction

declare @string varchar(max)
declare @result varchar(max)
declare @response varchar(max)

set @string = '{"RESPONSE":{"value":["d"],"isAnswered":true}}'

set @response = SUBSTRING(@string, PATINDEX('%response%',@string), PATINDEX('%":{"value"%',@string) - PATINDEX('%response%',@string))

print @response
-- for html tags

DECLARE @htmlTags TABLE 
(
    ID INT IDENTITY(1,1), 
    htmlTag varchar(50)
);

INSERT INTO @htmlTags
VALUES 
    ('<p>'),
    ('</p>'),
    ('<h1>'),
    ('</h1>'),
    ('"'),
    ('{'),
    ('}'),
    (':'),
    (','),
    ('value'),
    ('isAnswered'),
    ('true'),
    ('false'),
    ('&nbsp;'),
    ('['),
    (']')
;

SET @result = @string

DECLARE @temp varchar(max) = '';
WHILE @result != @temp
BEGIN
    SET @temp = @result;

    SELECT
        @result = Replace(@result, htmlTag, '')
    FROM
        @htmlTags
    ;
END;

set @result = REPLACE(@result, @response, '')

print @result

rollback

I'm assuming that the structure of your JSON response is:

{"RESPONSE":{"value":"","isAnswered":true}}

EDIT: I recommend to insert all html tags and names (like ) into the htmlTags table to obtain the result you want since you cannot predict which one of them is going to appear in the json.

UPDATE: use this set @response = SUBSTRING(@string, PATINDEX('%response%',@string), PATINDEX('%":{"value"%',@string) - PATINDEX('%response%',@string)) so you can replace any kind of RESPONSE pattern in your json.

Hope it helps.