Question

我在下面的Mongodb 3.2中有一个示例mongodb数据，并希望只获得与＆＃39; Cooking /＆＃39;

相关的文档bookCategory.categoryCode

{"_id": {"$oid":"5808578b33fa6f161c9747f8"},"_class":"exceltest.TestBean","bookName":"Test6","revenue":10.0,"unitsSold":1,"bookCategory":[{"categoryCode":"Cooking/"},{"categoryCode":"Cooking/Beverages"},{"categoryCode":"Food Receipe/"},{"categoryCode":"Food Receipe/Bartending"},{"categoryCode":"Cooking/Beverages/Bartending"},{"categoryCode":"Food Receipe/Taste"}]}
{"_id":{"$oid":"5808578b33fa6f161c9747f9"},"_class":"exceltest.TestBean","bookName":"Test1","revenue":11.0,"unitsSold":2,"bookCategory":[{"categoryCode":"Cooking/"},{"categoryCode":"Cooking/Beverages"},{"categoryCode":"Food Receipe/"},{"categoryCode":"Food Receipe/Bartending"},{"categoryCode":"Cooking/Beverages/Bartending"},{"categoryCode":"Food Receipe/Taste"}]}
{"_id":{"$oid":"5808578b33fa6f161c9747fa"},"_class":"exceltest.TestBean","bookName":"Test2","revenue":12.0,"unitsSold":3,"bookCategory":[{"categoryCode":"Cooking/"},{"categoryCode":"Cooking/Beverages"},{"categoryCode":"Food Receipe/"},{"categoryCode":"Food Receipe/Bartending"},{"categoryCode":"Cooking/Beverages/Bartending"},{"categoryCode":"Food Receipe/Taste"}]}
{"_id":{"$oid":"5808578b33fa6f161c9747fb"},"_class":"exceltest.TestBean","bookName":"Test3","revenue":13.0,"unitsSold":4,"bookCategory":[{"categoryCode":"Cooking/"},{"categoryCode":"Cooking/Beverages"},{"categoryCode":"Food Receipe/"},{"categoryCode":"Food Receipe/Bartending"},{"categoryCode":"Cooking/Beverages/Bartending"},{"categoryCode":"Food Receipe/Taste"}]}
 {"_id":{"$oid":"5808578b33fa6f161c9747fc"},"_class":"exceltest.TestBean","bookName":"Test4","revenue":14.0,"unitsSold":5,"bookCategory":[{"categoryCode":"Cooking/"},{"categoryCode":"Cooking/Beverages"},{"categoryCode":"Food Receipe/"},{"categoryCode":"Food Receipe/Bartending"},{"categoryCode":"Cooking/Beverages/Bartending"},{"categoryCode":"Food Receipe/Taste"}]}
{"_id":{"$oid":"5808578b33fa6f161c9747fd"},"_class":"exceltest.TestBean","bookName":"Test5","revenue":15.0,"unitsSold":6,"bookCategory":[{"categoryCode":"Cooking/"},{"categoryCode":"Cooking/Beverages"},{"categoryCode":"Food Receipe/"},{"categoryCode":"Food Receipe/Bartending"},{"categoryCode":"Cooking/Beverages/Bartending"},{"categoryCode":"Food Receipe/Taste"}]}
{"_id":{"$oid":"5808578b33fa6f161c9747fe"},"_class":"exceltest.TestBean","bookName":"Test10","revenue":16.0,"unitsSold":7,"bookCategory":[{"categoryCode":"Cooking/"},{"categoryCode":"Cooking/Beverages"},{"categoryCode":"Food Receipe/"},{"categoryCode":"Food Receipe/Bartending"},{"categoryCode":"Cooking/Beverages/Bartending"},{"categoryCode":"Food Receipe/Taste"}]}
 {"_id":{"$oid":"5808578b33fa6f161c9747ff"},"_class":"exceltest.TestBean","bookName":"Test11","revenue":100.0,"unitsSold":100,"bookCategory":[{"categoryCode":"Cooking/"},{"categoryCode":"Cooking/Beverages"},{"categoryCode":"Food Receipe/"},{"categoryCode":"Food Receipe/Bartending"},{"categoryCode":"Cooking/Beverages/Bartending"},{"categoryCode":"Food Receipe/Taste"}]}
 {"_id":{"$oid":"580857b833fa6f0c3499e462"},"_class":"exceltest.TestBean","bookName":"Test1","revenue":20.0,"unitsSold":10,"bookCategory":[{"categoryCode":"Cooking/"},{"categoryCode":"Cooking/Beverages"},{"categoryCode":"Food Receipe/"},{"categoryCode":"Food Receipe/Bartending"}]}
 {"_id":{"$oid":"580857b833fa6f0c3499e463"},"_class":"exceltest.TestBean","bookName":"Test2","revenue":19.0,"unitsSold":9,"bookCategory":[{"categoryCode":"Cooking/"},{"categoryCode":"Cooking/Beverages"},{"categoryCode":"Food Receipe/"},{"categoryCode":"Food Receipe/Bartending"}]}
{"_id":{"$oid":"580857b833fa6f0c3499e464"},"_class":"exceltest.TestBean","bookName":"Test3","revenue":18.0,"unitsSold":8,"bookCategory":[{"categoryCode":"Cooking/"},{"categoryCode":"Cooking/Beverages"},{"categoryCode":"Food Receipe/"},{"categoryCode":"Food Receipe/Bartending"}]}
 {"_id":{"$oid":"580857b833fa6f0c3499e465"},"_class":"exceltest.TestBean","bookName":"Test4","revenue":17.0,"unitsSold":7,"bookCategory":[{"categoryCode":"Cooking/"},{"categoryCode":"Cooking/Beverages"},{"categoryCode":"Food Receipe/"},{"categoryCode":"Food Receipe/Bartending"}]}
{"_id":{"$oid":"580857b833fa6f0c3499e466"},"_class":"exceltest.TestBean","bookName":"Test5","revenue":16.0,"unitsSold":6,"bookCategory":[{"categoryCode":"Cooking/"},{"categoryCode":"Cooking/Beverages"},{"categoryCode":"Food Receipe/"},{"categoryCode":"Food Receipe/Bartending"}]}
 {"_id":{"$oid":"580857b833fa6f0c3499e467"},"_class":"exceltest.TestBean","bookName":"Test1","revenue":15.0,"unitsSold":5,"bookCategory":[{"categoryCode":"Cooking/"},{"categoryCode":"Cooking/Beverages"},{"categoryCode":"Food Receipe/"},{"categoryCode":"Food Receipe/Bartending"}]}
 {"_id":{"$oid":"580857b833fa6f0c3499e468"},"_class":"exceltest.TestBean","bookName":"Test2","revenue":14.0,"unitsSold":4,"bookCategory":[{"categoryCode":"Cooking/"},{"categoryCode":"Cooking/Beverages"},{"categoryCode":"Food Receipe/"},{"categoryCode":"Food Receipe/Bartending"}]}
 {"_id":{"$oid":"580857b833fa6f0c3499e469"},"_class":"exceltest.TestBean","bookName":"Test3","revenue":13.0,"unitsSold":3,"bookCategory":[{"categoryCode":"Cooking/"},{"categoryCode":"Cooking/Beverages"},{"categoryCode":"Food Receipe/"},{"categoryCode":"Food Receipe/Bartending"}]}
{"_id":{"$oid":"580857b833fa6f0c3499e46a"},"_class":"exceltest.TestBean","bookName":"Test4","revenue":12.0,"unitsSold":2,"bookCategory":[{"categoryCode":"Cooking/"},{"categoryCode":"Cooking/Beverages"},{"categoryCode":"Food Receipe/"},{"categoryCode":"Food Receipe/Bartending"}]}
{"_id":{"$oid":"580857b833fa6f0c3499e46b"},"_class":"exceltest.TestBean","bookName":"Test5","revenue":11.0,"unitsSold":1,"bookCategory":[{"categoryCode":"Cooking/"},{"categoryCode":"Cooking/Beverages"},{"categoryCode":"Food Receipe/"},{"categoryCode":"Food Receipe/Bartending"}]}

这是我的查询：

 db.books.aggregate([
 {$match:{'bookCategory.categoryCode' :  {$regex : 'Cooking/'}}},
  {$unwind:'$bookCategory'}, 


{ "$group": {
"_id": {
    "categoryCode": "$bookCategory.categoryCode",
    "book": "$bookName"
},
"revenue": { $sum:"$revenue" },
 "unitsSold": { $sum:"$unitsSold" }
}
 }]);

我收到与类别相关的文件＆＃39; Food Receipe / Bartending＆＃39; Food's Foodipe /＆＃39;随着＆＃39;烹饪/＆＃39;类别。以下是示例输出：

/* 1 */
{
"_id" : {
    "categoryCode" : "Cooking/",
    "book" : "Test6"
},
"revenue" : 10.0,
"unitsSold" : 1
}

/* 2 */ 
{
"_id" : {
    "categoryCode" : "Food Receipe/Bartending",
    "book" : "Test4"
},
"revenue" : 43.0,
"unitsSold" : 14
}

/* 3 */
 {
"_id" : {
    "categoryCode" : "Cooking/",
    "book" : "Test1"
},
"revenue" : 46.0,
"unitsSold" : 17
}

/* 4 */
{
"_id" : {
    "categoryCode" : "Food Receipe/Taste",
    "book" : "Test2"
},
"revenue" : 12.0,
"unitsSold" : 3
}

 /*And so on upto 48 documents*/

我正在尝试匹配＆＃39;烹饪/＆＃39;但它检索不匹配的文件。请帮助仅检索匹配＆＃39;烹饪/＆＃39;的子文档。＆＃39;烹饪/饮料＆＃39;烹饪/饮料/调酒＆＃39;。

此致克里斯

Answer 1

我通过交换$ unwind和$ match的位置得到了答案，是否记录在mongodb的任何地方？请解释这个“位置交换”如何解决我的问题，并为我找到针对此问题的优化查询。

 db.books.aggregate([
 {$unwind:'$bookCategory'}, /*Position swapped*/
{$match:{'bookCategory.categoryCode' :  {$regex : 'Cooking/'}}} /*Position swapped*/ ,
{ "$group": {
 "_id": {

"categoryCode": "$bookCategory.categoryCode",

  "book": "$bookName"

}，

 "revenue": { $sum:"$revenue" },

 "unitsSold": { $sum:"$unitsSold" }

}

  }]);

此致

克里斯

正则表达式匹配在mongodb-3.2中不起作用

1 个答案: