微信小程序连接云数据库基本使用

数据库基本使用"/>

微信小程序连接云数据库基本使用

微信小程序连接云数据库基本使用

demo_list数据库

这里仅仅展示了基本使用和常用函数，微信官方文档链接：
微信小程序云数据库官方文档

一、连接数据库

const db=wx.cloud.database()

二、操作数据库

1.get 函数

获取 demo_list 数据库数据

db.collection("demo_list").get({success: res=>{console.log(res)}
})

2. doc 函数

按照 doc 的条件获取 demo_list 数据库数据

db.collection("demo_list").doc("f18e14fa652e8708032637034ac9ef78").get({success: res=>{console.log(res)}
})

3.add 函数

用 add 函数添加数据，同时使用 promise 回调测试添加的数据

addData(){// 数据加载中...wx.showLoading({title: '数据加载中...',mask: true})// 添加元素db.collection("demo_list").add({data:{user_name: "唐平",address: "上海市嘉定区",mobile: "135956252456"}}).then(res=>{console.log(res)})

4、update 函数

db.collection("demo_list").doc("41d77edc652e93b407906cd65d1c4e56").update({data:{// 如果字段存在则更改，不存在则新增字段user_name: "王五"}
}).then(res=>{console.log(res)
})

按照条件查询更新（updated为1更新成功）

{"stats":{"updated":1},"errMsg":"document.update:ok"
}

5、set 函数

按照条件覆盖之前的属性

db.collection("demo_list").doc("41d77edc652e93b407906cd65d1c4e56").set({data:{user_name: "王六",postTime: "2020-10-10"}
}).then(res=>{console.log(JSON.stringify(res))
})

6、del 删除

db.collection("demo_list").doc("a5782af7652e93e8000333250819c3ca").remove().then(res=>{console.log(res)
})

按照条件删除（removed为1删除成功）

{"stats":{"removed":1},"errMsg":"document.remove:ok"
}

7、count 获取个数

    db.collection("demo_list").count().then(res=>{console.log(res)})

8、watch监听（必须要有 onChange 与 onError 进行回调）

db.collection("demo_list").watch({onChange:res=>{console.log(res)},onError:err=>{console.log(err)}
})

测试删除：

删除前输出为（ 删除 id 为 41d77edc652e93b407906cd65d1c4e56 的记录 ）：

{"id": 0,"docChanges": [{"id": 0,"dataType": "init","queueType": "init","docId": "f18e14fa652e8708032637034ac9ef78","doc": {"_id": "f18e14fa652e8708032637034ac9ef78","address": "福建省 漳州市 龙文区","mobile": "13596288733","user_name": "唐平"}}, {"id": 0,"dataType": "init","queueType": "init","docId": "a5782af7652e87eb00025cfa6abf49bb","doc": {"_id": "a5782af7652e87eb00025cfa6abf49bb","address": "澳门特别行政区 离岛","mobile": "18943772748","user_name": "易超"}}, {"id": 0,"dataType": "init","queueType": "init","docId": "8de6ebcc652e882d079b2a4d019657ed","doc": {"_id": "8de6ebcc652e882d079b2a4d019657ed","address": "云南省 西双版纳傣族自治州 其它区","mobile": "13588962266","user_name": "段涛"}}, {"id": 0,"dataType": "init","queueType": "init","docId": "41d77edc652e93b407906cd65d1c4e56","doc": {"_id": "41d77edc652e93b407906cd65d1c4e56","_openid": "oJId45WOKC6BGonpsL61Qv0ZEVas","address": "上海市嘉定区","mobile": "135956252456","postTime": "2020-10-10","user_name": "王六"}}, {"id": 0,"dataType": "init","queueType": "init","docId": "7dc1d502652e93bf07972139040bd3fa","doc": {"_id": "7dc1d502652e93bf07972139040bd3fa","_openid": "oJId45WOKC6BGonpsL61Qv0ZEVas","address": "上海市嘉定区","mobile": "135956252456","user_name": "唐平"}}],"docs": [{"_id": "f18e14fa652e8708032637034ac9ef78","address": "福建省 漳州市 龙文区","mobile": "13596288733","user_name": "唐平"}, {"_id": "a5782af7652e87eb00025cfa6abf49bb","address": "澳门特别行政区 离岛","mobile": "18943772748","user_name": "易超"}, {"_id": "8de6ebcc652e882d079b2a4d019657ed","address": "云南省 西双版纳傣族自治州 其它区","mobile": "13588962266","user_name": "段涛"}, {"_id": "41d77edc652e93b407906cd65d1c4e56","_openid": "oJId45WOKC6BGonpsL61Qv0ZEVas","address": "上海市嘉定区","mobile": "135956252456","postTime": "2020-10-10","user_name": "王六"}, {"_id": "7dc1d502652e93bf07972139040bd3fa","_openid": "oJId45WOKC6BGonpsL61Qv0ZEVas","address": "上海市嘉定区","mobile": "135956252456","user_name": "唐平"}],"type": "init","requestId": "1697879416647_0.9092538129463852","watchId": "watchid_1697879416228_0.7892680514541097"
}

删除后输出为：

{"id": 1,"docChanges": [{"id": 1,"dataType": "remove","queueType": "dequeue","docId": "7dc1d502652e93bf07972139040bd3fa","doc": {"_id": "7dc1d502652e93bf07972139040bd3fa","_openid": "oJId45WOKC6BGonpsL61Qv0ZEVas","address": "上海市嘉定区","mobile": "135956252456","user_name": "唐平"}}],"docs": [{"_id": "f18e14fa652e8708032637034ac9ef78","address": "福建省 漳州市 龙文区","mobile": "13596288733","user_name": "唐平"}, {"_id": "a5782af7652e87eb00025cfa6abf49bb","address": "澳门特别行政区 离岛","mobile": "18943772748","user_name": "易超"}, {"_id": "8de6ebcc652e882d079b2a4d019657ed","address": "云南省 西双版纳傣族自治州 其它区","mobile": "13588962266","user_name": "段涛"}, {"_id": "41d77edc652e93b407906cd65d1c4e56","_openid": "oJId45WOKC6BGonpsL61Qv0ZEVas","address": "上海市嘉定区","mobile": "135956252456","postTime": "2020-10-10","user_name": "王六"}],"requestId": "1697879416647_0.9092538129463852","watchId": "watchid_1697879416228_0.7892680514541097"
}

删除：

{"stats": {"removed": 1},"errMsg": "document.remove:ok"
}

9、limit 限制查询

// 限制一次性查询3个
db.collection("demo_list").limit(3).get().then(res=>{console.log(res)
})

10、orderBy 排序

// 根据 time 升序排序（升序：asc、降序：desc）
db.collection("demo_list").orderBy("time","asc").limit(3)
.get().then(res=>{console.log(JSON.stringify(res))
})

{"data": [{"_id": "f18e14fa652e8708032637034ac9ef78","address": "福建省 漳州市 龙文区","mobile": "13596288733","time": "2023-10-21T15:05:52.462Z","user_name": "唐平"},{"_id": "a5782af7652e87eb00025cfa6abf49bb","address": "澳门特别行政区 离岛","mobile": "18943772748","time": "2023-10-21T15:06:34.244Z","user_name": "易超"},{"_id": "8de6ebcc652e882d079b2a4d019657ed","address": "云南省 西双版纳傣族自治州 其它区","mobile": "13588962266","time": "2023-10-21T15:06:49.219Z","user_name": "段涛"}],"errMsg": "collection.get:ok"
}

11、skip函数

// skip跳过三条（如果limit限制三条，skip相当于查询第二页）
db.collection("demo_list").orderBy("time","asc").limit(3).skip(3).get().then(res=>{console.log(JSON.stringify(res))})

12、field 函数

// field 接收我们想要的数据,user_name与address为true表示接收
db.collection("demo_list").orderBy("time","asc").limit(3).skip(0).field({user_name: true,address: true }).get().then(res=>{console.log(JSON.stringify(res))})

输出结果：

{"data": [{"_id": "f18e14fa652e8708032637034ac9ef78","address": "福建省 漳州市 龙文区","user_name": "唐平"},{"_id": "a5782af7652e87eb00025cfa6abf49bb","address": "澳门特别行政区 离岛","user_name": "易超"},{"_id": "8de6ebcc652e882d079b2a4d019657ed","address": "云南省 西双版纳傣族自治州 其它区","user_name": "段涛"}],"errMsg": "collection.get:ok"
}

三、Command

1、command

官方建议这样定义 command：

const db=wx.cloud.database()
const _ = dbmand

2、where条件查询

// 查询地址为“福建省 漳州市 龙文区”的用户
db.collection("demo_list").where({address: "福建省 漳州市 龙文区"}).get().then(res=>{console.log(JSON.stringify(res));this.setData({dataList: res.data})
})

控制台输出结果：

{"data": [{"_id": "f18e14fa652e8708032637034ac9ef78","address": "福建省 漳州市 龙文区","mobile": "13596288733","time": "2023-10-21T15:05:52.462Z","user_name": "唐平"}],"errMsg": "collection.get:ok"
}

3、eq 相等

// 查询地址为“福建省 漳州市 龙文区”的用户
db.collection("demo_list")
.where({// 等价于address: "福建省 漳州市 龙文区"// _ 是开头定义的 “_ = dbmand”address: _.eq("福建省 漳州市 龙文区")
})
.get()
.then(res=>{console.log(JSON.stringify(res));this.setData({dataList: res.data})
})

4、neq 不相等

db.collection("demo_list").where({// 查询地址不为 “福建省 漳州市 龙文区”address: _.neq("福建省 漳州市 龙文区")}).get().then(res=>{console.log(JSON.stringify(res));this.setData({dataList: res.data
})

控制台输出：

{"data": [{"_id": "a5782af7652e87eb00025cfa6abf49bb","address": "澳门特别行政区 离岛","mobile": "18943772748","time": "2023-10-21T15:06:34.244Z","user_name": "易超"}, {"_id": "8de6ebcc652e882d079b2a4d019657ed","address": "云南省 西双版纳傣族自治州 其它区","mobile": "13588962266","time": "2023-10-21T15:06:49.219Z","user_name": "段涛"}, {"_id": "41d77edc652e93b407906cd65d1c4e56","_openid": "oJId45WOKC6BGonpsL61Qv0ZEVas","address": "上海市嘉定区","mobile": "135956252456","postTime": "2020-10-10","time": "2023-10-21T15:07:12.707Z","user_name": "王六"}],"errMsg": "collection.get:ok"
}

5、lte 小于等于

.where({// 查询xxx小于等于5个xxx: _.lte(5)
})

6、lt 小于

.where({// 查询xxx小于5个xxx: _.lt(5)
})

7、gte 大于等于

.where({// 查询xxx大于等于5个xxx: _.gte(5)
})

8、gt 大于

.where({// 查询xxx大于5个xxx: _.gt(5)
})

9、in 包含

.where({// 参数是列表，查询包含澳门和云南省的信息address: _.in(["澳门特别行政区 离岛","云南省 西双版纳傣族自治州 其它区"])})

控制台输出：

{"data": [{"_id": "a5782af7652e87eb00025cfa6abf49bb","address": "澳门特别行政区 离岛","mobile": "18943772748","time": "2023-10-21T15:06:34.244Z","user_name": "易超"}, {"_id": "8de6ebcc652e882d079b2a4d019657ed","address": "云南省 西双版纳傣族自治州 其它区","mobile": "13588962266","time": "2023-10-21T15:06:49.219Z","user_name": "段涛"}],"errMsg": "collection.get:ok"
}

10、nin 不包含

.where({// 参数是列表，查询不包含澳门和云南省的信息（黑名单）address: _.nin(["澳门特别行政区 离岛","云南省 西双版纳傣族自治州 其它区"])})

控制台输出：

{"data": [{"_id": "f18e14fa652e8708032637034ac9ef78","address": "福建省 漳州市 龙文区","mobile": "13596288733","time": "2023-10-21T15:05:52.462Z","user_name": "唐平"}, {"_id": "41d77edc652e93b407906cd65d1c4e56","_openid": "oJId45WOKC6BGonpsL61Qv0ZEVas","address": "上海市嘉定区","mobile": "135956252456","postTime": "2020-10-10","time": "2023-10-21T15:07:12.707Z","user_name": "王六"}],"errMsg": "collection.get:ok"
}

11、and 多个条件同时满足

.where({// 查询 hits 在 100-400 之间hits:_.and(_.gt(100),_.lte(400))
})

12、 or 满足其中一个条件即可

.where({// 查询 hits 等于 235 或 等于 222hits:_.or(_.eq(235),_.eq(222))
})

13、where查询多个字段

如果使用 _.or() 和 _.and() 只能针对一个字段

db.collection("demo_list").where().get().then(res=>{console.log(JSON.stringify(res));this.setData({dataList: res.data})
})

(1) 用户 叫 “唐平” 或 hits 小于 500

.where(_.or([{hits: _.lt(500)},{user_name: _.eq("唐平")}
]))

(2) 用户 叫 “唐平” 且 hits 大于 500

.where(_.and([{hits: _.gt(500)},{user_name: _.eq("唐平")}
]))

14、exists 查询有这个字段的数据

.where({time: _.exists(true)
})

返回有 time 字段的数据

15、mod 取余数学运算

用的不多，略

16、size 对字段中的数组进行操作

// 返回有两个数组长度的tabs的数据
.where({tabs: _.size(2)
})

17、all 同时包含几个条件

// 返回tabs为 ['数码','科技'] 的数据
.where({tabs: _.all(['数码','科技'])
})

18、elemMatch 数组字段的查询筛选条件

要求数组中包含至少一个满足 elemMatch 给定的所有条件的元素

// 找出 places 数组字段中至少同时包含一个满足 “area 大于 100 且 age 小于 2” 的元素
.where({places: _.elemMatch({area: _.gt(100),age: _.lt(2),})
})

19、inc 增加（参数为负数时也可以用来减少）

Number类型数据才可以

(1) 增加 hits

// hits 增加 5
db.collection("demo_list").doc("41d77edc652e93b407906cd65d1c4e56").update({data:{hits: _.inc(5)}}).then(res=>{console.log(JSON.stringify(res));this.setData({dataList: res.data})
})

(2) 减少 hits

// hits 减少 5
db.collection("demo_list").doc("41d77edc652e93b407906cd65d1c4e56").update({data:{hits: _.inc(-5)}}).then(res=>{console.log(JSON.stringify(res));this.setData({dataList: res.data})
})

20、删除某个字段

// 删除 id 对应的 postTime 字段
db.collection("demo_list").doc("41d77edc652e93b407906cd65d1c4e56").update({data:{postTime: _.remove()}}).then(res=>{console.log(JSON.stringify(res));this.setData({dataList: res.data})
})

21、set 把原来的字段对象给覆盖掉

db.collection("demo_list").doc("41d77edc652e93b407906cd65d1c4e56").update({data:{style: _.set({back: "pink"})}
})

22、min、max比大小…

略

23、push 对数组添加

(1) 不写 Number 默认在最后面添加

.updata({data:{// push 对数组字段后面添加"aaa"和"bbb"list: _.push(['aaa'],['bbb'])}
})

(2) 指定追加位置

.updata({data:{// push 对数组字段后面添加"aaa"和"bbb"list: _.push({each:['新视觉','实训'],// 下标从0开始position: 1})}
})

24、pop 删除数组最后一个元素

.updata({data:{// 删除数组最后的元素list: _.pop()}
})

25、unshift 对数组字段后面添加

.updata({data:{// 在数组开头添加多个元素tabs:_.unshift(['智能','新闻'])}
})

26、shift 删除数组第一个元素

.updata({data:{// 在数组开头添加多个元素tabs:_.shift()}
})

27、pull 移除数组中匹配的元素

.updata({data:{// 移除数组中的“数码”tabs:_.pull('数码')}
})