You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: djangocontenttype.xo.go
    path of file: ./repos/xo/_examples/django/mysql
    
    the code of the file until where you have to start completion: package mysql

// Code generated by xo. DO NOT EDIT.

import (
	"context"
)

// DjangoContentType represents a row from 'django.django_content_type'.
type DjangoContentType struct {
	ID       int    `json:"id"`        // id
	AppLabel string `json:"app_label"` // app_label
	Model    string `json:"model"`     // model
	// xo fields
	_exists, _deleted bool
}

// Exists returns true when the [DjangoContentType] exists in the database.
func (dct *DjangoContentType)
    
func DjangoContentTypeByAppLabelModel(ctx context.Context, db DB, appLabel, model string) (*DjangoContentType, error) {
	// query
	const sqlstr = `SELECT ` +
		`id, app_label, model ` +
		`FROM django.django_content_type ` +
		`WHERE app_label = ? AND model = ?`
	// run
	logf(sqlstr, appLabel, model)
	dct := DjangoContentType{
		_exists: true,
	}
	if err := db.QueryRowContext(ctx, sqlstr, appLabel, model).Scan(&dct.ID, &dct.AppLabel, &dct.Model); err != nil {
		return nil, logerror(err)
	}
	return &dct, nil
}