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MongoDB的模糊查询操作(类关系型数据库的 like 和 not like)

2019年07月19日 22:51  | 萬仟网IT编程  | 我要评论

1.作用与语法描述

作用: 正则表达式是使用指定字符串来描述、匹配一系列符合某个句法规则的字符串。许多程序设计语言都支持利用正则表达式进行字符串操作。mongodb 使用 $regex 操作符来设置匹配字符串的正则表达式。

语法一

{ <field>: { $regex: /pattern/, $options: '<options>' } }
{ <field>: { $regex: 'pattern', $options: '<options>' } }
{ <field>: { $regex: /pattern/<options> } }

语法二

{ <field>: /pattern/<options> }

 

2.案例演示

假设mongodb中存放了我们orderservice服务的消息信息,其数据如下:

(以下为演示所用到的9个文档)

{
    "_id" : objectid("5d305b1c4857fc49c0c14c81"),
    "order" : "qq00001",
    "data" : "\"<?xml version='1.0' encoding='utf-8'?><response service=\\\"orderservice\\\"><head>err</head><error>重复下单</error></response>\""
},

{
    "_id" : objectid("5d305b3b4857fc49c0c14c82"),
    "order" : "qq00001",
    "data" : "\"<?xml version='1.0' encoding='utf-8'?><response service=\\\"orderservice\\\"><head>err</head><error>重复下单</error></response>\""
},

{
    "_id" : objectid("5d305b404857fc49c0c14c83"),
    "order" : "qq00002",
    "data" : "\"<?xml version='1.0' encoding='utf-8'?><response service=\\\"orderservice\\\"><head>err</head><error>重复下单</error></response>\""
},

{
    "_id" : objectid("5d305b454857fc49c0c14c84"),
    "order" : "qq00002",
    "data" : "\"<?xml version='1.0' encoding='utf-8'?><response service=\\\"orderservice\\\"><head>err</head><error>重复下单</error></response>\""
},

{
    "_id" : objectid("5d305b4b4857fc49c0c14c85"),
    "order" : "qq00003",
    "data" : "\"<?xml version='1.0' encoding='utf-8'?><response service=\\\"orderservice\\\"><head>err</head><error>重复下单</error></response>\""
},

{
    "_id" : objectid("5d305b4f4857fc49c0c14c86"),
    "order" : "qq00003",
    "data" : "\"<?xml version='1.0' encoding='utf-8'?><response service=\\\"orderservice\\\"><head>err</head><error>重复下单</error></response>\""
},

{
    "_id" : objectid("5d305bb74857fc49c0c14c87"),
    "order" : "qq00003",
    "data" : "\"<?xml version='1.0' encoding='utf-8'?><response service=\\\"orderservice\\\"><head>ok</head><body><orderresponse filter_mmm=\\\"2\\\" destcity=\\\"shenzheng\\\" origincode=\\\"qq0003\\\" /></body></response>\""
},

{
    "_id" : objectid("5d305bd14857fc49c0c14c88"),
    "order" : "qq00002",
    "data" : "\"<?xml version='1.0' encoding='utf-8'?><response service=\\\"orderservice\\\"><head>ok</head><body><orderresponse filter_mmm=\\\"2\\\" destcity=\\\"zhongshan\\\" origincode=\\\"qq0002\\\" /></body></response>\""
},

{
    "_id" : objectid("5d305be94857fc49c0c14c89"),
    "order" : "qq00001",
    "data" : "\"<?xml version='1.0' encoding='utf-8'?><response service=\\\"orderservice\\\"><head>ok</head><body><orderresponse filter_mmm=\\\"2\\\" destcity=\\\"zhongshan\\\" origincode=\\\"qq0001\\\" /></body></response>\""
}

 

需求: 查询 data 字段 含有 字符 <head>ok</head>的文档

执行代码如下:

 db.dbtestregex.find({data:{ $regex:/<head>ok<\/head>/}}) 

查询代码中的 \ 为转移符,以下查询语句也是如此。

返回结果如下:

{
    "_id" : objectid("5d305bb74857fc49c0c14c87"),
    "order" : "qq00003",
    "data" : "\"<?xml version='1.0' encoding='utf-8'?><response service=\\\"orderservice\\\"><head>ok</head><body><orderresponse filter_mmm=\\\"2\\\" destcity=\\\"shenzheng\\\" origincode=\\\"qq0003\\\" /></body></response>\""
},


{
    "_id" : objectid("5d305bd14857fc49c0c14c88"),
    "order" : "qq00002",
    "data" : "\"<?xml version='1.0' encoding='utf-8'?><response service=\\\"orderservice\\\"><head>ok</head><body><orderresponse filter_mmm=\\\"2\\\" destcity=\\\"zhongshan\\\" origincode=\\\"qq0002\\\" /></body></response>\""
},


{
    "_id" : objectid("5d305be94857fc49c0c14c89"),
    "order" : "qq00001",
    "data" : "\"<?xml version='1.0' encoding='utf-8'?><response service=\\\"orderservice\\\"><head>ok</head><body><orderresponse filter_mmm=\\\"2\\\" destcity=\\\"zhongshan\\\" origincode=\\\"qq0001\\\" /></body></response>\""
}

上面的查询命令也可以改写成:

 db.dbtestregex.find({data:/<head>ok<\/head>/})

其查询结果是一样的,如下:

{
    "_id" : objectid("5d305bb74857fc49c0c14c87"),
    "order" : "qq00003",
    "data" : "\"<?xml version='1.0' encoding='utf-8'?><response service=\\\"orderservice\\\"><head>ok</head><body><orderresponse filter_mmm=\\\"2\\\" destcity=\\\"shenzheng\\\" origincode=\\\"qq0003\\\" /></body></response>\""
},


{
    "_id" : objectid("5d305bd14857fc49c0c14c88"),
    "order" : "qq00002",
    "data" : "\"<?xml version='1.0' encoding='utf-8'?><response service=\\\"orderservice\\\"><head>ok</head><body><orderresponse filter_mmm=\\\"2\\\" destcity=\\\"zhongshan\\\" origincode=\\\"qq0002\\\" /></body></response>\""
},


{
    "_id" : objectid("5d305be94857fc49c0c14c89"),
    "order" : "qq00001",
    "data" : "\"<?xml version='1.0' encoding='utf-8'?><response service=\\\"orderservice\\\"><head>ok</head><body><orderresponse filter_mmm=\\\"2\\\" destcity=\\\"zhongshan\\\" origincode=\\\"qq0001\\\" /></body></response>\""
}

 还可以写成:

db.dbtestregex.find({data:{ $regex:'<head>ok<\/head>'}})

其实现功能一样。

3.类关系型数据库中的 not like 功能实现

反向查询虽然不常见,但也是我们dba必须的。下面我们做一个案例演示,看看在mongodb中,怎么实现not like 功能的查询。

需求 查询data 字段中不含  <head>ok</head>的文档

执行脚本如下:

 
 db.dbtestregex.find({data:{ $not: /<head>ok<\/head>/ }})  

返回的文档如下;

{
    "_id" : objectid("5d305b1c4857fc49c0c14c81"),
    "order" : "qq00001",
    "data" : "\"<?xml version='1.0' encoding='utf-8'?><response service=\\\"orderservice\\\"><head>err</head><error>重复下单</error></response>\""
},


{
    "_id" : objectid("5d305b3b4857fc49c0c14c82"),
    "order" : "qq00001",
    "data" : "\"<?xml version='1.0' encoding='utf-8'?><response service=\\\"orderservice\\\"><head>err</head><error>重复下单</error></response>\""
},


{
    "_id" : objectid("5d305b404857fc49c0c14c83"),
    "order" : "qq00002",
    "data" : "\"<?xml version='1.0' encoding='utf-8'?><response service=\\\"orderservice\\\"><head>err</head><error>重复下单</error></response>\""
},


{
    "_id" : objectid("5d305b454857fc49c0c14c84"),
    "order" : "qq00002",
    "data" : "\"<?xml version='1.0' encoding='utf-8'?><response service=\\\"orderservice\\\"><head>err</head><error>重复下单</error></response>\""
},


{
    "_id" : objectid("5d305b4b4857fc49c0c14c85"),
    "order" : "qq00003",
    "data" : "\"<?xml version='1.0' encoding='utf-8'?><response service=\\\"orderservice\\\"><head>err</head><error>重复下单</error></response>\""
},


{
    "_id" : objectid("5d305b4f4857fc49c0c14c86"),
    "order" : "qq00003",
    "data" : "\"<?xml version='1.0' encoding='utf-8'?><response service=\\\"orderservice\\\"><head>err</head><error>重复下单</error></response>\""
}

 

更多内容可参照官方文档  https://docs.mongodb.com/manual/reference/operator/query/regex/#op._s_regex

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