MongoDB使用游标来处理找到查询到的结果文档集;
游标的使用实例:
祝辞,var 游标=db.post.find ({“name.firstname”:“乔”}),,,
祝辞,cursor ,,,
{," _id ": ObjectId (“54 ace1394ba07ed75df68f90”),“名字”,:,{,“firstname”:“乔”,“姓”,:,“schome”,},,“年龄”,:,28,},,,,
{," _id ": ObjectId (“54 ace753eab1d0ba4abb48ab”),“名字”,:,{,“firstname”:“乔”,“姓”,:,“schome”,},,“年龄”,:,30,},,,,
{," _id ": ObjectId (“54 ace777eab1d0ba4abb48ac”),“名字”,:,{,“firstname”:“乔”,“姓”,:,“schome”,“评论”,:,10,},,“年龄”,:,30,},,,,
{," _id ": ObjectId (“54 ace781eab1d0ba4abb48ad”),“名字”,:,{,“firstname”:“乔”,“姓”,:,“schome”,“评论”,:,6,},,“年龄”,:,30,},,,,
{," _id ": ObjectId (“54 ace785eab1d0ba4abb48ae”),“名字”,:,{,“firstname”:“乔”,“姓”,:,“schome”,“评论”,:,5,},,“年龄”,:,30,},,,,
{," _id ": ObjectId (“54 ace789eab1d0ba4abb48af”),“名字”,:,{,“firstname”:“乔”,“姓”,:,“schome”,“评论”,:,7,},,“年龄”,:,30,},,,,
在 使用极限来返回前两个记录:
祝辞,cursor.limit (2),,,
{," _id ": ObjectId (“54 ace1394ba07ed75df68f90”),“名字”,:,{,“firstname”:“乔”,“姓”,:,“schome”,},,“年龄”,:,28,},,,,
{," _id ": ObjectId (“54 ace753eab1d0ba4abb48ab”),“名字”,:,{,“firstname”:“乔”,“姓”,:,“schome”,},,“年龄”,:,30,},,,,
在 或者使用跳来跳过前3个记录:
祝辞,cursor.skip (3),,,
{," _id ": ObjectId (“54 ace781eab1d0ba4abb48ad”),“名字”,:,{,“firstname”:“乔”,“姓”,:,“schome”,“评论”,:,6,},,“年龄”,:,30,},,,,
{," _id ": ObjectId (“54 ace785eab1d0ba4abb48ae”),“名字”,:,{,“firstname”:“乔”,“姓”,:,“schome”,“评论”,:,5,},,“年龄”,:,30,},,,,
:{" _id "还以为;ObjectId (“54 ace789eab1d0ba4abb48af”),“名字”,:,{,“firstname”:“乔”,“姓”,:,“schome”,“评论”,:,7,},,“年龄”,:,30,},,,,
以前,在 或者使用类指定键值排序:,
祝辞,cursor.sort({“年龄”:1}),,,,
{," _id ": ObjectId (“54 ace1394ba07ed75df68f90”),“名字”,:,{,“firstname”:“乔”,“姓”,:,“schome”,},,“年龄”,:,28,},,,,
{," _id ": ObjectId (“54 ace753eab1d0ba4abb48ab”),“名字”,:,{,“firstname”:“乔”,“姓”,:,“schome”,},,“年龄”,:,30,},,,,
{," _id ": ObjectId (“54 ace777eab1d0ba4abb48ac”),“名字”,:,{,“firstname”:“乔”,“姓”,:,“schome”,“评论”,:,10,},,“年龄”,:,30,},,,,
{," _id ": ObjectId (“54 ace781eab1d0ba4abb48ad”),“名字”,:,{,“firstname”:“乔”,“姓”,:,“schome”,“评论”,:,6,},,“年龄”,:,30,},,,,
{," _id ": ObjectId (“54 ace785eab1d0ba4abb48ae”),“名字”,:,{,“firstname”:“乔”,“姓”,:,“schome”,“评论”,:,5,},,“年龄”,:,30,},,,,
{," _id ": ObjectId (“54 ace789eab1d0ba4abb48af”),“名字”,:,{,“firstname”:“乔”,“姓”,:,“schome”,“评论”,:,7,},,“年龄”,:,30,}
综合使用/限制/跳过,当然可以调整顺序得到不同的结果:
祝辞,cursor.sort ({“name.comment”: 1}) .skip (2) .limit (1)
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