1.作用與語法描述
作用： 正則表達式是使用指定字符串來描述、匹配一系列符合某個句法規(guī)則的字符串。許多程序設計語言都支持利用正則表達式進行字符串操作。MongoDB 使用 $regex 操作符來設置匹配字符串的正則表達式。
語法一
{ field>: { $regex: /pattern/, $options: 'options>' } }
{ field>: { $regex: 'pattern', $options: 'options>' } }
{ field>: { $regex: /pattern/options> } }
語法二
{ field>: /pattern/options> }
2.案例演示
假設MongoDB中存放了我們OrderService服務的消息信息，其數(shù)據(jù)如下：
（以下為演示所用到的9個文檔）
{
"_id" : ObjectId("5d305b1c4857fc49c0c14c81"),
"order" : "QQ00001",
"data" : "\"?xml version='1.0' encoding='UTF-8'?>Response service=\\\"OrderService\\\">Head>ERR/Head>ERROR>重復下單/ERROR>/Response>\""
},
{
"_id" : ObjectId("5d305b3b4857fc49c0c14c82"),
"order" : "QQ00001",
"data" : "\"?xml version='1.0' encoding='UTF-8'?>Response service=\\\"OrderService\\\">Head>ERR/Head>ERROR>重復下單/ERROR>/Response>\""
},
{
"_id" : ObjectId("5d305b404857fc49c0c14c83"),
"order" : "QQ00002",
"data" : "\"?xml version='1.0' encoding='UTF-8'?>Response service=\\\"OrderService\\\">Head>ERR/Head>ERROR>重復下單/ERROR>/Response>\""
},
{
"_id" : ObjectId("5d305b454857fc49c0c14c84"),
"order" : "QQ00002",
"data" : "\"?xml version='1.0' encoding='UTF-8'?>Response service=\\\"OrderService\\\">Head>ERR/Head>ERROR>重復下單/ERROR>/Response>\""
},
{
"_id" : ObjectId("5d305b4b4857fc49c0c14c85"),
"order" : "QQ00003",
"data" : "\"?xml version='1.0' encoding='UTF-8'?>Response service=\\\"OrderService\\\">Head>ERR/Head>ERROR>重復下單/ERROR>/Response>\""
},
{
"_id" : ObjectId("5d305b4f4857fc49c0c14c86"),
"order" : "QQ00003",
"data" : "\"?xml version='1.0' encoding='UTF-8'?>Response service=\\\"OrderService\\\">Head>ERR/Head>ERROR>重復下單/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： 查詢 data 字段 含有 字符 Head>OK/Head>的文檔
執(zhí)行代碼如下：
db.dbtestregex.find({data:{ $regex:/Head>OK\/Head>/}})
查詢代碼中的 \ 為轉移符，以下查詢語句也是如此。
返回結果如下：
{
"_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>\""
}
上面的查詢命令也可以改寫成：
db.dbtestregex.find({data:/Head>OK\/Head>/})
其查詢結果是一樣的，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>\""
}
還可以寫成：
db.dbtestregex.find({data:{ $regex:'Head>OK\/Head>'}})
其實現(xiàn)功能一樣。
3.類關系型數(shù)據(jù)庫中的 not like 功能實現(xiàn)
反向查詢雖然不常見，但也是我們DBA必須的。下面我們做一個案例演示，看看在MongoDB中，怎么實現(xiàn)not like 功能的查詢。
需求 查詢data 字段中不含 Head>OK/Head>的文檔
執(zhí)行腳本如下：
db.dbtestregex.find({data:{ $not: /Head>OK\/Head>/ }})
返回的文檔如下;
{
"_id" : ObjectId("5d305b1c4857fc49c0c14c81"),
"order" : "QQ00001",
"data" : "\"?xml version='1.0' encoding='UTF-8'?>Response service=\\\"OrderService\\\">Head>ERR/Head>ERROR>重復下單/ERROR>/Response>\""
},
{
"_id" : ObjectId("5d305b3b4857fc49c0c14c82"),
"order" : "QQ00001",
"data" : "\"?xml version='1.0' encoding='UTF-8'?>Response service=\\\"OrderService\\\">Head>ERR/Head>ERROR>重復下單/ERROR>/Response>\""
},
{
"_id" : ObjectId("5d305b404857fc49c0c14c83"),
"order" : "QQ00002",
"data" : "\"?xml version='1.0' encoding='UTF-8'?>Response service=\\\"OrderService\\\">Head>ERR/Head>ERROR>重復下單/ERROR>/Response>\""
},
{
"_id" : ObjectId("5d305b454857fc49c0c14c84"),
"order" : "QQ00002",
"data" : "\"?xml version='1.0' encoding='UTF-8'?>Response service=\\\"OrderService\\\">Head>ERR/Head>ERROR>重復下單/ERROR>/Response>\""
},
{
"_id" : ObjectId("5d305b4b4857fc49c0c14c85"),
"order" : "QQ00003",
"data" : "\"?xml version='1.0' encoding='UTF-8'?>Response service=\\\"OrderService\\\">Head>ERR/Head>ERROR>重復下單/ERROR>/Response>\""
},
{
"_id" : ObjectId("5d305b4f4857fc49c0c14c86"),
"order" : "QQ00003",
"data" : "\"?xml version='1.0' encoding='UTF-8'?>Response service=\\\"OrderService\\\">Head>ERR/Head>ERROR>重復下單/ERROR>/Response>\""
}
更多內容可參照官方文檔 https://docs.mongodb.com/manual/reference/operator/query/regex/#op._S_regex
總結
以上所述是小編給大家介紹的MongoDB模糊查詢操作案例詳解(類關系型數(shù)據(jù)庫的 like 和 not like),希望對大家有所幫助，如果大家有任何疑問請給我留言，小編會及時回復大家的。在此也非常感謝大家對腳本之家網(wǎng)站的支持！
如果你覺得本文對你有幫助，歡迎轉載，煩請注明出處，謝謝！
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