sql query for searching within columns with json documents - mysql

Question

I am using MySQL 5.7 and one of the columns in my table contains multiple JSON documents. Some thing like:
'[ {
"animal" : "dog",
"data" : {
"body" : "This sentence does not contain any thing about grooming",
}
},
{
"animal" : "cat",
"data" : {
"body" : "No grooming needed"
}
},
{
"animal" : "horse",
"data" : {
"body" : "He is grooming his horse after the ride."
}
}
]'
I want to return all rows where $.data.body contains grooming more than once, but only if $.animal == horse. So in the example given above it should not return the row since grooming is used only once in the section $.data.body where $.animal == horse.
Is there a good way to query this in MySql/SQL? I can do it in python but interested in knowing if there's a way to do this in SQL/MySQL. Thanks!

Answer 1

Searching JSON requires complex queries, and it is hard to optimize:
SELECT ...
FROM mytable
CROSS JOIN JSON_TABLE(myjsoncolumn, '$[*]' COLUMNS(
animal varchar(20) PATH '$.animal',
body text PATH '$.data.body'
)) AS j
WHERE j.animal = 'horse' AND j.body LIKE '%grooming%';
The JSON_TABLE() function is available in MySQL 8.0.4, but not earlier versions of MySQL.
The bottom line is that if you are trying to search the content of JSON documents, your use of SQL is going to be a lot more difficult and less efficient.
This would be far easier if you did not store the data in JSON, but instead stored data in normal rows and columns. From the example you show, there's no reason it needs to be JSON.