索引
自动创建和手工创建
db.stu.drop(); db.stu.insert({"name":"张三","sex":"男","age":18,"score":70,"address":"河南"}); db.stu.insert({"name":"李四","sex":"女","age":20,"score":60,"address":"山东"}); db.stu.insert({"name":"王五","sex":"男","age":17,"score":44,"address":"江苏"}); db.stu.insert({"name":"赵六","sex":"男","age":21,"score":80,"address":"山东"}); db.stu.insert({"name":"孙七","sex":"女","age":23,"score":50,"address":"湖北"}); db.stu.insert({"name":"tom","sex":"男","age":24,"score":20,"address":"海南"}); db.stu.insert({"name":"lucy","sex":"女","age":21,"score":62,"address":"浙江"}); db.stu.insert({"name":"jack","sex":"男","age":20,"score":90,"address":"美国"}); db.stu.insert({"name":"smith","sex":"男","age":19,"score":88,"address":"美国"});