text: const Service = require("egg").Service;
  
  class BillService extends Service {
    async add(params) {
      const { ctx, app } = this;
      try {
        const result = await app.mysql.insert("bill", params);
        return result;
      } catch (err) {
        console.error(err);
        return null;
      }
    }
  
    async list(id) {
      const { ctx, app } = this;
      const QUERY_STR = "id, pay_type, amount, date, type_id, type_name, remark";
      let sql = `select ${QUERY_STR} from bill where user_id = ${id}`;
      try {
        const result = await app.mysql.query(sql);
        return result;
      } catch (err) {
        console.log(error);
        return null;
      }
    }
  
    async detail(id, user_id) {
      const { ctx, app } = this;
      try {
        const result = await app.mysql.get("bill", { id, user_id });
        return result;
      } catch (error) {
        console.log(error);
        return null;
      }
    }
  
    async update(params) {
      const { ctx, app } = this;
      try {
        let result = await app.mysql.update(
          "bill",
          {
            ...params,
          },
          {
            id: params.id,
            user_id: params.user_id,
          }
        );
        return result;
      } catch (error) {
        console.log(error);
        return null;
      }
    }
    async delete(id, user_id) {
      const { ctx, app } = this;
      try {
        let result = await app.mysql.delete("bill", {
          id: id,
          user_id: user_id,
        });
        return result;
      } catch (error) {
        console.log(error);
        return null;
      }
    }
  }
  
  module.exports = BillService;
  