在我的数据库中,我有一个name
字段。在某些记录中,它是一个空字符串,在其他记录中,它有一个名称。
在我的查询中,我目前正在做:
db.users.find({}).sort({'name': 1})
但是,这将首先返回带有空名称字段的结果,然后按字母顺序返回结果。正如所料,执行.sort({'name': -1})
会返回带有名称的结果,然后使用空字符串返回结果,但它是按字母顺序排列的。
有没有一种优雅的方式来实现这种类型的排序?
答案 0 :(得分:1)
如果您要过滤掉空Pre-populate the directory with some random file names
AIG-taral-3486.txt
COV-oipuc-9088.txt
CUG-vowan-5758.txt
FEH-ieqek-0603.txt
IUS-aaduw-7080.txt
KER-jazuc-4824.txt
MIZ-iezec-8255.txt
NIT-kupib-6873.txt
PUX-oocov-2216.txt
QAW-xonod-3937.txt
QES-wawok-4790.txt
RON-difag-1986.txt
SAD-gesug-5706.txt
SAJ-luqoj-4311.txt
TUZ-wapaw-8547.txt
VAL-zutap-8054.txt
YIP-xudeb-7397.txt
YUP-uudiv-8848.txt
ZIB-jurax-2903.txt
ZUR-xonik-8800.txt
aavfile*147*.txt
demo.sh
diman\\\7115.txt
ganur\\\8732.txt
gud-{7049}-{3103}.txt
listfilesbefore.swp
lur[123]maee.txt
rivfile*065*.txt
ueo(417)yea.txt
uoi(751)qio.txt
woi-{37E8}-{009C}.txt
xof[123]hoxe.txt
Create some new files with metacharacters in the names
AIG-taral-3486.txt
COV-oipuc-9088.txt
CUG-vowan-5758.txt
FEH-ieqek-0603.txt
IUS-aaduw-7080.txt
KER-jazuc-4824.txt
MIZ-iezec-8255.txt
NIT-kupib-6873.txt
PUX-oocov-2216.txt
QAW-xonod-3937.txt
QES-wawok-4790.txt
RON-difag-1986.txt
SAD-gesug-5706.txt
SAJ-luqoj-4311.txt
TUZ-wapaw-8547.txt
VAL-zutap-8054.txt
YIP-xudeb-7397.txt
YUP-uudiv-8848.txt
ZIB-jurax-2903.txt
ZUR-xonik-8800.txt
aavfile*147*.txt
demo.sh
diman\\\7115.txt
ganur\\\8732.txt
gud-{7049}-{3103}.txt
listfilesbefore.swp
lur[123]maee.txt
new(123)file.txt
new[123]file.txt
newfile*321*.txt
newfile-{A39F}-{B77D}.txt
newfile\\\.txt
rivfile*065*.txt
ueo(417)yea.txt
uoi(751)qio.txt
woi-{37E8}-{009C}.txt
xof[123]hoxe.txt
Create sed script
/^AIG-taral-3486\.txt$/d
/^COV-oipuc-9088\.txt$/d
/^CUG-vowan-5758\.txt$/d
/^FEH-ieqek-0603\.txt$/d
/^IUS-aaduw-7080\.txt$/d
/^KER-jazuc-4824\.txt$/d
/^MIZ-iezec-8255\.txt$/d
/^NIT-kupib-6873\.txt$/d
/^PUX-oocov-2216\.txt$/d
/^QAW-xonod-3937\.txt$/d
/^QES-wawok-4790\.txt$/d
/^RON-difag-1986\.txt$/d
/^SAD-gesug-5706\.txt$/d
/^SAJ-luqoj-4311\.txt$/d
/^TUZ-wapaw-8547\.txt$/d
/^VAL-zutap-8054\.txt$/d
/^YIP-xudeb-7397\.txt$/d
/^YUP-uudiv-8848\.txt$/d
/^ZIB-jurax-2903\.txt$/d
/^ZUR-xonik-8800\.txt$/d
/^aavfile\*147\*\.txt$/d
/^demo\.sh$/d
/^diman\\\\\\7115\.txt$/d
/^ganur\\\\\\8732\.txt$/d
/^gud-{7049}-{3103}\.txt$/d
/^listfilesbefore\.swp$/d
/^lur\[123\]maee\.txt$/d
/^rivfile\*065\*\.txt$/d
/^ueo(417)yea\.txt$/d
/^uoi(751)qio\.txt$/d
/^woi-{37E8}-{009C}\.txt$/d
/^xof\[123\]hoxe\.txt$/d
Apply it
listfilesafter.swp
new(123)file.txt
new[123]file.txt
newfile*321*.txt
newfile-{A39F}-{B77D}.txt
newfile\\\.txt
字段的文档,请更改您的查询:"name"