Forum OpenACS Development: Re: From database to JSON

set sql "select user_id, username,  last_visit from users"
set json_arr [::tjson::parse {[]}]
db_foreach get_users $sql {
   ::tjson::add_item_to_array $json_arr \
        [list M \
                [list \
                        user_id [list N $user_id] \
                        username [list S $username] \
                        last_visit [list S $last_visit]]]
}
doc_return 200 application/json [::tjson::to_pretty_json $json_arr]
ad_script_abort

And here is what you get:

[
  {
    "user_id": 0,
    "username": "guest",
    "last_visit": ""
  },
  {
    "user_id": 759,
    "username": "test",
    "last_visit": "2023-07-26 09:27:37.590777-04"
  }
]

M means it is an object, N means it is a number, and S means it is a string. tjson also supports the triple notation that is used in mongodb driver (documentation for that feature is still pending).

I will add a create command though. Thanks for that.

Can you provide an example where tDOM fails to parse a valid JSON?

Please download this file: https://raw.githubusercontent.com/stripe/openapi/master/openapi/spec3.json

and then run:

package require tdom
set fp [open "spec3.json"]
set data [read $fp]
close $fp
puts [time "dom parse -json $data test" 1

I get: error "JSON syntax error" at position 15

tjson runs fine with it:

package require tjson
set fp [open "spec3.json"]
set data [read $fp]
close $fp
puts [time "::tjson::parse $data" 1]

=> 18316 microseconds for tjson

It's probably something that I am doing wrong. Please let me know if you have better luck with it.