ToolJet/app/services/mysql_query_service.rb

class MysqlQueryService

    attr_accessor :data_query, :data_source, :options, :source_options, :current_user

    def initialize(data_query, options, source_options, current_user)
        @data_query = data_query
        @data_source = data_query.data_source
        @options = options
        @source_options = source_options
        @current_user = current_user
    end

    def process
        if $connections.include? data_source.id
            connection = $connections[data_source.id][:connection]
        else
            connection = client = Mysql2::Client.new(
                host: source_options["host"], 
                username: source_options["username"],
                password:source_options["password"],
                port: source_options["port"],
                database: source_options["database"], 
            )

            $connections[data_source.id] = { connection: connection }
        end

        query_text = options["query"]

        results = connection.query(query_text)

        { status: 'success', data: results.to_a }
    end
end