Javascript 从JSON查询对应的密钥
我在mongo db中有以下json结构Javascript 从JSON查询对应的密钥,javascript,json,mongodb,Javascript,Json,Mongodb,我在mongo db中有以下json结构 { "branch": [ { "section": [ { "sub": "edc", "time": "one hour", "frequency": "3" }, { "sub": "bee", "time": "two hours", "fr
{
"branch": [
{
"section": [
{
"sub": "edc",
"time": "one hour",
"frequency": "3"
},
{
"sub": "bee",
"time": "two hours",
"frequency": "4"
}
]
},
{
"section": [
{
"sub": "ss",
"time": "one hour",
"frequency": "2"
},
{
"sub": "ms",
"time": "two hours",
"frequency": "5"
}
]
}
]
}
我希望执行一个查询,使其只返回以下键的值
分部
在查询之后,我希望输出如下
edc
bee
ss
ms
使用“查找:
同意RickyA的观点--
但您可能希望从结果中取消显示_id:
此外,如果您只希望输出为字段的值,可以尝试使用forEach函数进行打印,例如:
db.test.find( {},
{"branch.section.sub":1, _id: 0}
).forEach( function (x) {
for (i = 0; i < x.branch.length; i++) {
section = x.branch[i].section;
for (j = 0; j < section.length; j++ ) {
print( section[j].sub);
}
}
} )
db.test.find({},
{“branch.section.sub”:1,_id:0}
).forEach(函数(x){
对于(i=0;i
提示:如果您没有使用问号,您可能没有问任何问题……请尝试jsonpath
library
db.test.find( {},
{"branch.section.sub":1, _id: 0}
).forEach( function (x) {
for (i = 0; i < x.branch.length; i++) {
section = x.branch[i].section;
for (j = 0; j < section.length; j++ ) {
print( section[j].sub);
}
}
} )