透過多個數組項在 MongoDB 中查詢?
可以使用 $all 運算子透過多個數組項查詢。要理解這個概念,讓我們建立一個帶有文件的集合。
建立帶有文件的集合的查詢如下:
> db.findByMultipleArrayDemo.insertOne({"StudentFirstName":"John","StudentLastName":"Smith", "StudentCoreSubject":["Compiler","Operating System","Computer Networks"]}); { "acknowledged" : true, "insertedId" : ObjectId("5c7ef07b559dd2396bcfbfc4") } > db.findByMultipleArrayDemo.insertOne({"StudentFirstName":"Carol","StudentLastName":"Taylor", "StudentCoreSubject":["MongoDB","MySQL","SQL Server"]}); { "acknowledged" : true, "insertedId" : ObjectId("5c7ef09d559dd2396bcfbfc5") } > db.findByMultipleArrayDemo.insertOne({"StudentFirstName":"Bob","StudentLastName":"Taylor", "StudentCoreSubject":["MongoDB","MySQL","SQL Server"]}); { "acknowledged" : true, "insertedId" : ObjectId("5c7ef0c7559dd2396bcfbfc6") } > db.findByMultipleArrayDemo.insertOne({"StudentFirstName":"David","StudentLastName":"Johnson", "StudentCoreSubject":["Compiler","Operating System","Computer Networks"]}); { "acknowledged" : true, "insertedId" : ObjectId("5c7ef0f2559dd2396bcfbfc7") }
在集合中使用 find() 方法顯示所有文件。查詢如下:
> db.findByMultipleArrayDemo.find().pretty();
以下是輸出:
{ "_id" : ObjectId("5c7ef07b559dd2396bcfbfc4"), "StudentFirstName" : "John", "StudentLastName" : "Smith", "StudentCoreSubject" : [ "Compiler", "Operating System", "Computer Networks" ] } { "_id" : ObjectId("5c7ef09d559dd2396bcfbfc5"), "StudentFirstName" : "Carol", "StudentLastName" : "Taylor", "StudentCoreSubject" : [ "MongoDB", "MySQL", "SQL Server" ] } { "_id" : ObjectId("5c7ef0c7559dd2396bcfbfc6"), "StudentFirstName" : "Bob", "StudentLastName" : "Taylor", "StudentCoreSubject" : [ "MongoDB", "MySQL", "SQL Server" ] } { "_id" : ObjectId("5c7ef0f2559dd2396bcfbfc7"), "StudentFirstName" : "David", "StudentLastName" : "Johnson", "StudentCoreSubject" : [ "Compiler", "Operating System", "Computer Networks" ] }
以下是透過多個數組項查詢的查詢:
> db.findByMultipleArrayDemo.find({ StudentCoreSubject: { $all: ["Compiler", "Computer Networks"] }}).pretty();
以下是顯示帶有陣列項“Compiler”和“Computer Networks”的記錄的輸出:
{ "_id" : ObjectId("5c7ef07b559dd2396bcfbfc4"), "StudentFirstName" : "John", "StudentLastName" : "Smith", "StudentCoreSubject" : [ "Compiler", "Operating System", "Computer Networks" ] } { "_id" : ObjectId("5c7ef0f2559dd2396bcfbfc7"), "StudentFirstName" : "David", "StudentLastName" : "Johnson", "StudentCoreSubject" : [ "Compiler", "Operating System", "Computer Networks" ] }
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