数据库触发器模板

// schema扩展相关文档请参阅：https://uniapp.dcloud.net.cn/uniCloud/jql-schema-ext.html
module.exports = {
  trigger: {
    // 写入JQL数据库的标准写法
    // read触发器
    beforeRead: async function({
      collection,
      where,
      field,
      clientInfo,
      userInfo,
      result,
      triggerContext,
      subCollection,
      rawWhere,
      rawGeoNear,
      skip,
      limit,
      sample,
      docId,
      operation
    }) {
      //非jql操作系统库不会触发数据库触发器
      //const db = uniCloud.database()

      //调用JQL操作数据库
      /* const db = uniCloud.databaseForJQL({
          clientInfo,
          skipTrigger: true
      }) */

      //示例：修改文章更新时间
      /* const id = where && where._id
      if (typeof id === 'string' && (updateData.title || updateData.content)) { //如果字段较多，也可以不列举字段，删掉后半个判断
          if (updateData.content) {
              // updateData.summary = 'xxxx' // 根据content生成summary
          }
          updateData.update_date = Date.now() // 更新数据的update_date字段赋值为当前服务器时间
      } */
    },
    afterRead: async function({
      collection,
      where,
      field,
      clientInfo,
      userInfo,
      result,
      triggerContext,
      subCollection,
      rawWhere,
      rawGeoNear,
      skip,
      limit,
      sample,
      docId,
      operation
    }) {
      //调用JQL操作数据库
      /* const db = uniCloud.databaseForJQL({
          clientInfo,
          skipTrigger: true
      }) */

      //读取后触发实现阅读量加1
      /* const db = uniCloud.database()
      const id = where && where._id
      // clientInfo.uniIdToken可以解出客户端用户信息，再进行判断是否应该加1。为了让示例简单清晰，此处省略相关逻辑
      if (typeof id === 'string' && field.includes('content')) {
          // 读取了content字段后view_count加1
          await db.collection('article').where(where).update({
              view_count: db.command.inc(1)
          })
      } */
    },

    //create触发器
    beforeCreate: async function({
      collection,
      where,
      addDataList,
      clientInfo,
      userInfo,
      result,
      triggerContext,
      operation
    }) {
      //调用JQL操作数据库
      /* const db = uniCloud.databaseForJQL({
          clientInfo,
          skipTrigger: true
      }) */

      //示例：新增文章时自动添加摘要
      /* for (let i = 0; i < addDataList.length; i++) {
          const addDataItem = addDataList[i]
          if (!addDataItem.content) {
              throw new Error('缺少文章内容')
          }
          addDataItem.summary = addDataItem.content.slice(0, 100)
      } */
    },
    afterCreate: async function({
      collection,
      where,
      addDataList,
      clientInfo,
      userInfo,
      result,
      triggerContext,
      operation
    }) {
      //调用JQL操作数据库
      /* const db = uniCloud.databaseForJQL({
          clientInfo,
          skipTrigger: true
      }) */
    },

    //update触发器
    beforeUpdate: async function({
      collection,
      where,
      updateData,
      clientInfo,
      userInfo,
      result,
      triggerContext,
      rawWhere,
      docId,
      operation
    }) {
      //调用JQL操作数据库
      /* const db = uniCloud.databaseForJQL({
          clientInfo,
          skipTrigger: true
      }) */
    },
    afterUpdate: async function({
      collection,
      where,
      updateData,
      clientInfo,
      userInfo,
      result,
      triggerContext,
      rawWhere,
      docId,
      operation
    }) {
      //调用JQL操作数据库
      /* const db = uniCloud.databaseForJQL({
          clientInfo,
          skipTrigger: true
      }) */
    },

    //delete触发器
    beforeDelete: async function({
      collection,
      where,
      clientInfo,
      userInfo,
      result,
      triggerContext,
      rawWhere,
      docId,
      operation
    }) {
      //调用JQL操作数据库
      /* const db = uniCloud.databaseForJQL({
          clientInfo,
          skipTrigger: true
      }) */

      //示例：删除前备份
      /* const db = uniCloud.database()
      const id = where && where._id
      if (typeof id !== 'string') { // 此处也可以加入管理员可以批量删除的逻辑
          throw new Error('禁止批量删除')
      }
      const res = await db.collection('article').where(where).get()
      const record = res.data[0]
      if (record) {
          await db.collection('article-archived').add(record)
      } */
    },
    afterDelete: async function({
      collection,
      where,
      clientInfo,
      userInfo,
      result,
      triggerContext,
      rawWhere,
      docId,
      operation
    }) {
      //调用JQL操作数据库
      /* const db = uniCloud.databaseForJQL({
          clientInfo,
          skipTrigger: true
      }) */
    },

    //count触发器
    beforeCount: async function({
      collection,
      where,
      clientInfo,
      userInfo,
      result,
      triggerContext,
      operation
    }) {
      //调用JQL操作数据库
      /* const db = uniCloud.databaseForJQL({
          clientInfo,
          skipTrigger: true
      }) */
    },
    afterCount: async function({
      collection,
      where,
      clientInfo,
      userInfo,
      result,
      triggerContext,
      operation
    }) {
      //调用JQL操作数据库
      /* const db = uniCloud.databaseForJQL({
          clientInfo,
          skipTrigger: true
      }) */
    }
  }
}