在 MongoDB 中忽略特定字元的正則表示式?
您可以使用正則表示式和 $not 運算子來忽略特定的字元並顯示其它的字元。讓我們首先建立一個包含文件的集合 −
> db.regexDemo.insertOne({"CustomerId":"Customer#1234","CustomerName":"Chris"}); { "acknowledged" : true, "insertedId" : ObjectId("5cc7428f8f9e6ff3eb0ce436") } > db.regexDemo.insertOne({"CustomerId":"Customer5678","CustomerName":"Robert"}); { "acknowledged" : true, "insertedId" : ObjectId("5cc7429e8f9e6ff3eb0ce437") } > db.regexDemo.insertOne({"CustomerId":"Customer#777","CustomerName":"Carol"}); { "acknowledged" : true, "insertedId" : ObjectId("5cc742ae8f9e6ff3eb0ce438") } > db.regexDemo.insertOne({"CustomerId":"Customer777","CustomerName":"David"}); { "acknowledged" : true, "insertedId" : ObjectId("5cc742bc8f9e6ff3eb0ce439") }
以下是使用 find() 方法從集合中顯示所有文件的查詢 −
> db.regexDemo.find().pretty();
這將產生以下輸出 −
{ "_id" : ObjectId("5cc7428f8f9e6ff3eb0ce436"), "CustomerId" : "Customer#1234", "CustomerName" : "Chris" } { "_id" : ObjectId("5cc7429e8f9e6ff3eb0ce437"), "CustomerId" : "Customer5678", "CustomerName" : "Robert" } { "_id" : ObjectId("5cc742ae8f9e6ff3eb0ce438"), "CustomerId" : "Customer#777", "CustomerName" : "Carol" } { "_id" : ObjectId("5cc742bc8f9e6ff3eb0ce439"), "CustomerId" : "Customer777", "CustomerName" : "David" }
案例 1 − 以下是避免在 MongoDB 中使用特定字元的查詢。字元是 # −
> db.regexDemo.find({CustomerId: /^[^#]*$/}).pretty();
這將產生以下輸出 −
{ "_id" : ObjectId("5cc7429e8f9e6ff3eb0ce437"), "CustomerId" : "Customer5678", "CustomerName" : "Robert" } { "_id" : ObjectId("5cc742bc8f9e6ff3eb0ce439"), "CustomerId" : "Customer777", "CustomerName" : "David" }
案例 2 − 以下是避免在 MongoDB 中使用特定字元的另一個查詢。字元是 # −
> db.regexDemo.find({CustomerId: {$not: /#/}}).pretty();
這將產生以下輸出 −
{ "_id" : ObjectId("5cc7429e8f9e6ff3eb0ce437"), "CustomerId" : "Customer5678", "CustomerName" : "Robert" } { "_id" : ObjectId("5cc742bc8f9e6ff3eb0ce439"), "CustomerId" : "Customer777", "CustomerName" : "David" }
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