Error converting SUM() result to Int64 in MySQL

Question

I'm using MySQL v5.7.42 and Go v1.21.0 with the volatiletech/sqlboiler v3.7.1 library. I have a table with a JSON column, and I'm trying to sum values extracted from this JSON using JSON_EXTRACT().

Here's a simplified version of my setup:

CREATE TABLE users {
 name json NOT NULL 
}

mysql> select name from users;
+--------------------------------------------------------+
| name                                                   |
+--------------------------------------------------------+
| {"hoge1": {"fuga1": 100000}}                           |
| {"hoge2": {"fuga2": 1000000}}                          |
+--------------------------------------------------------+

In Go, I'm executing the following SQL queries and scanning the results into int64 variables:

import (
  ...
  "github.com/volatiletech/sqlboiler/queries"
  "database/sql"
)
...
var ( 
  v1 v2 int64
  db *sql.DB
)
...
row1 := queries.Raw(`
  select sum(JSON_EXTRACT(name, '$.hoge1.fuga1')) as piyo from users;
`).QueryRow(db)

err := row1.Scan(&v1)
fmt.Printf("%v, err\n", v1, err) // output: 100000, nil

row2 := queries.Raw(`
  select sum(JSON_EXTRACT(name, '$.hoge2.fuga2')) as piyo from users;
`).QueryRow(db)

err = row2.Scan(&v2)
fmt.Printf("%v, err\n", v2, err) // output: 0, Scan error on column index 0, name "piyo": converting driver.Value type float64 ("1e+06") to a int64: invalid syntax

The first query works as expected, but the second query returns the following error:

Scan error on column index 0, name "piyo": converting driver.Value type float64 ("1e+06") to a int64: invalid syntax

My Questions:

• Why does SUM() (or JSON_EXTRACT()?) return a float64 for certain numbers?
• What is the best way to handle this situation to avoid the error? Should I cast the result to an integer in the SQL query, or is there a better approach in Go to handle this conversion?

Context:

What is the return type of SUM() in mysql?

The existing above question discusses the return type of SUM() but does not address issues with JSON_EXTRACT() specifically or how it interacts with different numeric types in the context of JSON data. My issue involves both SUM() and JSON_EXTRACT() which is not covered in the referenced question.