MongoDB query how to output only part of the field content 04/24 Update SLTechnology News&Howtos

MongoDB query how to output only part of the field content

2025-04-24 Update From: SLTechnology News&Howtos shulou NAV: SLTechnology News&Howtos > Database >

Shulou(Shulou.com)06/01 Report--

For example, the collection test has three columns id,url and data. Now we only want to output the id and url fields, which can be looked up as follows:

> db.test.find ({}, {id: 1, url: 1})

{"_ id": ObjectId ("5ad8a51bb5cec3000b17f39d"), "url": "http://info.zjktx.cn/urlsearch.php?info_flag=6&url=915ad2673221b5ab17ba29e24d00efc3"}

{"_ id": ObjectId ("5ad8a51bb5cec3000b17f39e"), "url": "http://mp.weixin.qq.com/s?__biz=MzIwOTY0NjY5NA==&mid=2247487505&idx=3&sn=8bdfc5b35eaa5eb7d2dbc2ff6247bf06&chksm=9771f518a0067c0e982d834821f9a44b7eea39f60cff8d50886175bbe1c93b27c70a8af9bfd9&scene=0#rd"}

{"_ id": ObjectId ("5ad8a51bb5cec3000b17f39f"), "url": "http://weibo.com/6432427115/GcR5t3Fh9"}

{"_ id": ObjectId ("5ad8a51bb5cec3000b17f3a0"), "url": "http://weibo.com/6503912228/GcR5ftPt7"}

{"_ id": ObjectId ("5ad8a51bb5cec3000b17f3a1"), "url": "http://mp.weixin.qq.com/s?__biz=MzU1NzE3MTEzOQ==&mid=2247486132&idx=7&sn=e031435df54cc5c6dcbdab4136c73222&chksm=fc38a218cb4f2b0e0b581ea5d7ef13f95d29321b385fe51137c8cd102b715ebfb75c284aacb0&scene=0#rd"}

{"_ id": ObjectId ("5ad8a51bb5cec3000b17f3a2"), "url": "http://mp.weixin.qq.com/s?__biz=MzAxOTMxMTAxOA==&mid=2650490009&idx=2&sn=020a9d674e4f48da10f3ed376bdda67f&chksm=83c7145cb4b09d4a153515ef56755098bccfbca92f7fb379621ffbe4177fc8431181a2d1f2cc&scene=0#rd"}

{"_ id": ObjectId ("5ad8a51bb5cec3000b17f3a3"), "url": "http://mp.weixin.qq.com/s?__biz=MzI0NTU3NDY1NQ==&mid=2247487947&idx=1&sn=0daadc7945dd56fa7f1c7c61557646ed&chksm=e94d2f5bde3aa64dc6578e1ce9997c5cbe57fc0500222dd9939da33877168afb3297045a50f8&scene=0#rd"}

{"_ id": ObjectId ("5ad8a51bb5cec3000b17f3a4"), "url": "http://weibo.com/ttarticle/p/show?id=2309614230624788536034"}

{"_ id": ObjectId ("5ad8a51bb5cec3000b17f3a5"), "url": "http://mp.weixin.qq.com/s?__biz=MzA5ODU0NzQ4OA==&mid=2649879715&idx=1&sn=5bdf0a2ca64b51df037252da73fe9d1c&chksm=888ab6ecbffd3ffa97bc454aef5e490eb8c4d5bd79e7dd61c833107dd907e3b7b6600bb7d111&scene=0#rd"}

{"_ id": ObjectId ("5ad8a51cb5cec3000b17f3a6"), "url": "http://www.qddtj.com/qdtj/961445.html"}

{"_ id": ObjectId ("5ad8a51cb5cec3000b17f3a7"), "url": "http://weibo.com/3078765485/GcQPzAWxR"}

{"_ id": ObjectId ("5ad8a51cb5cec3000b17f3a8"), "url": "http://weibo.com/1981850854/GcJ0KkXuz"}

{"_ id": ObjectId ("5ad8a51cb5cec3000b17f3a9"), "url": "http://weibo.com/2824592185/GcQQ9Dpu4"}

{"_ id": ObjectId ("5ad8a51cb5cec3000b17f3aa"), "url": "http://weibo.com/6456176195/GcQR69zDX"}

{"_ id": ObjectId ("5ad8a51cb5cec3000b17f3ab"), "url": "http://weibo.com/5996334075/GcR3UrMgN"}

{"_ id": ObjectId ("5ad8a51cb5cec3000b17f3ac"), "url": "http://weibo.com/3802294663/GcR5LDlyR"}

{"_ id": ObjectId ("5ad8a51cb5cec3000b17f3ad"), "url": "http://weibo.com/2428661490/GcQZL45qh"}

{"_ id": ObjectId ("5ad8a51cb5cec3000b17f3ae"), "url": "http://weibo.com/1762661765/GcR0LrC9O"}

{"_ id": ObjectId ("5ad8a51cb5cec3000b17f3af"), "url": "http://weibo.com/6135218321/GcQH544Rs"}

{"_ id": ObjectId ("5ad8a51cb5cec3000b17f3b0"), "url": "http://weibo.com/5996334075/GcR3OewDh"}

Type "it" for more

Note: the first parameter is the query condition, and an empty parameter represents the query for all

/ / if you do not want a field, you can use the method of excluding fields

For example, exclude the contents of the data field:

> db.test.find ({}, {data: 0})

{"_ id": ObjectId ("5ad8a51bb5cec3000b17f39d"), "url": "http://info.zjktx.cn/urlsearch.php?info_flag=6&url=915ad2673221b5ab17ba29e24d00efc3"," error: "BSON document too large (25962119 bytes)-the connected server supports BSON document sizes up to 16793598 bytes."}