Chèn trường boolean trong MongoDB

MongoDB hỗ trợ kiểu boolean native true và false. Chèn trực tiếp giá trị boolean vào trường.

Tạo collection với trường boolean

> db.demo215.insertOne({"EmployeeDetails":[{EmployeeName:"David","isMarried":false,"Salary":56000}]});
{ "acknowledged" : true, "insertedId" : ObjectId("5e3e344003d395bdc2134708") }
> db.demo215.insertOne({"EmployeeDetails":[{EmployeeName:"Bob","isMarried":true,"Salary":60000}]});
{ "acknowledged" : true, "insertedId" : ObjectId("5e3e344d03d395bdc2134709") }
> db.demo215.insertOne({"EmployeeDetails":[{EmployeeName:"Chris","isMarried":false,"Salary":78000}]});
{ "acknowledged" : true, "insertedId" : ObjectId("5e3e345a03d395bdc213470a") }
> db.demo215.insertOne({"EmployeeDetails":[{EmployeeName:"Mike","isMarried":true,"Salary":17000}]});
{ "acknowledged" : true, "insertedId" : ObjectId("5e3e346f03d395bdc213470b") }

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> db.demo215.find();

{ "_id" : ObjectId("5e3e344003d395bdc2134708"), "EmployeeDetails" : [ { "EmployeeName" : "David", "isMarried" : false, "Salary" : 56000 } ] }
{ "_id" : ObjectId("5e3e344d03d395bdc2134709"), "EmployeeDetails" : [ { "EmployeeName" : "Bob", "isMarried" : true, "Salary" : 60000 } ] }
{ "_id" : ObjectId("5e3e345a03d395bdc213470a"), "EmployeeDetails" : [ { "EmployeeName" : "Chris", "isMarried" : false, "Salary" : 78000 } ] }
{ "_id" : ObjectId("5e3e346f03d395bdc213470b"), "EmployeeDetails" : [ { "EmployeeName" : "Mike", "isMarried" : true, "Salary" : 17000 } ] }

Lưu ý:

• Boolean trong MongoDB: true, false (không dùng chuỗi "true"/"false")
• Truy vấn boolean: {isMarried: true}, {isMarried: {$ne: true}}, {isMarried: {$exists: true}}
• Index boolean ít hiệu quả do cardinality thấp (chỉ 2 giá trị). Nên dùng compound index
• Trong shell, true/false không cần quotes