Read MySQL JSON datatype and cast it into List<Int> in C#

Question

I am trying to return a list of numbers from mysql database which has JSON datatype in the table.

the mysql.connector in c# thinks the datatype is VARCHAR so basically I get in return "[1, 2, 3]" from the database.

I need to cast the string return into List<INT> so I can work with it directly.

to be more specific, that's what I get from the mysql reader

string mylist = "[1, 2, 3]"

and I want to cast it into

List<Int> mylist_int = [1, 2, 3]

So if there is a way to read JSON datatype from the database directly in JSON format that would be great.

alternatively I am looking for a way to parse the string list and convert it into c# native list.

Thank you,

Answer 1

Use a JSON parser like JSON.NET to parse the JSON string, eg :

var json=reader.GetString(0);
//Returns a List<int>
var myList=JsonConvert.DeserializeObject<List<int>>(json);

or

var jsonArray=JArray.Parse(json);

MySQL Connector explicitly treats JSON as a string, it doesn't "think" they are text :

    case MySqlDbType.Set:
    case MySqlDbType.Enum:
    case MySqlDbType.String:
    case MySqlDbType.VarString:
    case MySqlDbType.VarChar:
    case MySqlDbType.Text:
    case MySqlDbType.TinyText:
    case MySqlDbType.MediumText:
    case MySqlDbType.LongText:
    case MySqlDbType.JSON:
    case (MySqlDbType)Field_Type.NULL:
      return new MySqlString(type, true);

The library's own tests use GetString() to read JSON data :

[Fact]
public void CanReadJsonValue()
{
  ...
  using (MySqlDataReader reader = cmd.ExecuteReader())
  {
    Assert.True(reader.Read());
    Assert.Equal("[\"a\", {\"b\": [true, false]}, [10, 20]]", reader.GetString(0));
  }    
}