文檔間的關係
一、One to One
例:夫妻
db.WifeAndHusband.insert([
{
name:"黃蓉",husband:{name:"郭靖"}
},
{
name:"潘金蓮",husband:{name:"武大郎"}
},
])
db.WifeAndHusband.find()
二、One to Many(Many to One)
例: 用戶-訂單 文章-評論
db.users.insert([
{username:"swk"},{username:"zbj"}
])
db.order.insert({
list:["漫畫","肉"],
user_id:ObjectId("5d48ef25c57dfb3261f4086c")
})
db.order.find()
查找用戶swk訂單, 修改username 即可查詢不同訂單
var user_id = db.users.findOne({username:"zbj"})._id
user_id
db.order.find({user_id:user_id})
三、Many to Many 即user_id字段變數組
例:分類-商品,老師-學生*/
db.students.find()
db.teachers.insert([
{name:"洪七公"},
{name:"黃藥師"},
{name:"龜仙人"}
]);
db.students.insert([
{name:"郭靖",
teach_ids:[ObjectId("5d48f250c57dfb3261f40870"),ObjectId("5d48f250c57dfb3261f40871")]
}
])
db.students.insert([
{name:"孫悟空",
teach_ids:[ObjectId("5d48f250c57dfb3261f40870"),ObjectId("5d48f250c57dfb3261f40871"),ObjectId("5d48f250c57dfb3261f40872")]
}
])
*待解決:多對多查詢方法