要获取MongoDB集合中文档的数量，可以使用以下语法-
db.getCollectionNames().map(function(anyVariableName) {
return { "yourVariableName": yourVariableName, "count": db[yourVariableName].count() }
});在这里，我们正在使用“测试”数据库。
让我们实现以上语法以获取MongoDB集合中文档数的计数-
> db.getCollectionNames().map(function(ColName) {
... return { "ColName": ColName, "TotalDocument": db[ColName].count() }
... });这将产生以下输出-
[
{
"ColName" : "ConvertStringToDateDemo",
"TotalDocument" : 4
},
{
"ColName" : "Employee_Information",
"TotalDocument" : 2
},
{
"ColName" : "IdUpdateDemo",
"TotalDocument" : 3
},
{
"ColName" : "IndexingDemo",
"TotalDocument" : 1
},
{
"ColName" : "NotAndDemo",
"TotalDocument" : 5
},
{
"ColName" : "ProductsInformation",
"TotalDocument" : 2
},
{
"ColName" : "addCurrentDateTimeDemo",
"TotalDocument" : 4
},
{
"ColName" : "addFieldDemo",
"TotalDocument" : 1
},
{
"ColName" : "addNewFieldToEveryDocument",
"TotalDocument" : 4
},
{
"ColName" : "addingNewPropertyDemo",
"TotalDocument" : 3
},
{
"ColName" : "aggregateSumDemo",
"TotalDocument" : 4
},
{
"ColName" : "aggregationFrameworkWithOrMatchDemo",
"TotalDocument" : 6
},
{
"ColName" : "aggregationSortDemo",
"TotalDocument" : 6
},
{
"ColName" : "andOrDemo",
"TotalDocument" : 2
},
{
"ColName" : "arrayInnerElementsDemo",
"TotalDocument" : 1
},
{
"ColName" : "arrayLengthGreaterThanOne",
"TotalDocument" : 3
},
{
"ColName" : "arrayOfArraysDemo",
"TotalDocument" : 2
},
{
"ColName" : "averageAggregationDemo",
"TotalDocument" : 5
},
{
"ColName" : "avoidDuplicateEntriesDemo",
"TotalDocument" : 2
},
{
"ColName" : "caseInsensitiveDemo",
"TotalDocument" : 13
},
{
"ColName" : "caseInsesitiveDemo",
"TotalDocument" : 3
},
{
"ColName" : "castingDemo",
"TotalDocument" : 6
},
{
"ColName" : "changeDataType",
"TotalDocument" : 1
},
{
"ColName" : "changeIntegerToStringDemo",
"TotalDocument" : 4
},
{
"ColName" : "changeType",
"TotalDocument" : 1
},
{
"ColName" : "charactersAllowedDemo",
"TotalDocument" : 2
},
{
"ColName" : "charactersDemo",
"TotalDocument" : 3
},
{
"ColName" : "check",
"TotalDocument" : 1
},
{
"ColName" : "checkDemo",
"TotalDocument" : 2
},
{
"ColName" : "checkFieldContainsStringDemo",
"TotalDocument" : 6
},
{
"ColName" : "checkFieldExistsOrNotDemo",
"TotalDocument" : 4
},
{
"ColName" : "checkIfFieldIsNumberDemo",
"TotalDocument" : 4
},
{
"ColName" : "checkSequenceDemo",
"TotalDocument" : 3
},
{
"ColName" : "cloneObjectDemo",
"TotalDocument" : 5
},
{
"ColName" : "collectionOnDifferentDocumentDemo",
"TotalDocument" : 3
},
{
"ColName" : "combinationOfArrayDemo",
"TotalDocument" : 3
},
{
"ColName" : "comparingFieldDemo",
"TotalDocument" : 4
},
{
"ColName" : "comparingTwoFieldsDemo",
"TotalDocument" : 4
},
{
"ColName" : "componentOfDateDemo",
"TotalDocument" : 1
},
{
"ColName" : "concatStringAndIntDemo",
"TotalDocument" : 5
},
{
"ColName" : "concatenateStringsDemo",
"TotalDocument" : 5
},
{
"ColName" : "conditionalSumDemo",
"TotalDocument" : 8
},
{
"ColName" : "conditionalUpdatesDemo",
"TotalDocument" : 3
},
{
"ColName" : "conditionallyUpsertDemo",
"TotalDocument" : 3
},
{
"ColName" : "convertStringToNumberDemo",
"TotalDocument" : 3
},
{
"ColName" : "convertingISODateToNumerical",
"TotalDocument" : 3
},
{
"ColName" : "copyThisCollectionToSampleDatabaseDemo",
"TotalDocument" : 3
},
{
"ColName" : "countDemo",
"TotalDocument" : 4
},
{
"ColName" : "countNumberOfDocumentsDemo",
"TotalDocument" : 3
},
{
"ColName" : "countPerformanceDemo",
"TotalDocument" : 7
},
{
"ColName" : "createSequenceDemo",
"TotalDocument" : 1
},
{
"ColName" : "creatingUniqueIndexDemo",
"TotalDocument" : 3
},
{
"ColName" : "dateDemo",
"TotalDocument" : 1
},
{
"ColName" : "dateTimeValueLessThanNowDemo",
"TotalDocument" : 4
},
{
"ColName" : "deleteAllElementsInArrayDemo",
"TotalDocument" : 2
},
{
"ColName" : "deleteDocumentsDemo",
"TotalDocument" : 2
},
{
"ColName" : "deleteFieldDemo",
"TotalDocument" : 3
},
{
"ColName" : "deleteRecordDemo",
"TotalDocument" : 4
},
{
"ColName" : "deletingDocumentDemo",
"TotalDocument" : 3
},
{
"ColName" : "demo.insertCollection",
"TotalDocument" : 1
},
{
"ColName" : "determineFieldExistsDemo",
"TotalDocument" : 4
},
{
"ColName" : "distinctAggregation",
"TotalDocument" : 3
},
{
"ColName" : "distinctCountValuesDemo",
"TotalDocument" : 2
},
{
"ColName" : "distinctRecordDemo",
"TotalDocument" : 7
},
{
"ColName" : "distinctWithMultipleKeysDemo",
"TotalDocument" : 5
},
{
"ColName" : "doubleNestedArrayDemo",
"TotalDocument" : 2
},
{
"ColName" : "emailUniqueDemo",
"TotalDocument" : 2
},
{
"ColName" : "embeddedCollectionDemo",
"TotalDocument" : 0
},
{
"ColName" : "embeddedDocumentDemo",
"TotalDocument" : 0
},
{
"ColName" : "employeeInformation",
"TotalDocument" : 5
},
{
"ColName" : "equivalentForSelectColumn1Column2Demo",
"TotalDocument" : 3
},
{
"ColName" : "exactMatchArrayDemo",
"TotalDocument" : 2
},
{
"ColName" : "existsDemo",
"TotalDocument" : 1
},
{
"ColName" : "existsReturnDemo",
"TotalDocument" : 1
},
{
"ColName" : "extractSubArrayDemo",
"TotalDocument" : 1
},
{
"ColName" : "fieldIsNullOrNotSetDemo",
"TotalDocument" : 5
},
{
"ColName" : "filterArray",
"TotalDocument" : 1
},
{
"ColName" : "findADocumentWithCondition",
"TotalDocument" : 1
},
{
"ColName" : "findAllDuplicateKeyDocumentDemo",
"TotalDocument" : 7
},
{
"ColName" : "findAllNonDistinctDemo",
"TotalDocument" : 8
},
{
"ColName" : "findByFieldName",
"TotalDocument" : 2
},
{
"ColName" : "findByMultipleArrayDemo",
"TotalDocument" : 4
},
{
"ColName" : "findDocumentDoNotHaveCertainFields",
"TotalDocument" : 3
},
{
"ColName" : "findDocumentNonExistenceFieldDemo",
"TotalDocument" : 2
},
{
"ColName" : "findDocumentWithObjectIdDemo",
"TotalDocument" : 3
},
{
"ColName" : "findDuplicateByKeyDemo",
"TotalDocument" : 6
},
{
"ColName" : "findDuplicateRecordsDemo",
"TotalDocument" : 6
},
{
"ColName" : "findMinValueDemo",
"TotalDocument" : 5
},
{
"ColName" : "findMultipleWordsDemo",
"TotalDocument" : 6
},
{
"ColName" : "findRecordByIdDemo",
"TotalDocument" : 4
},
{
"ColName" : "findSpecificValue",
"TotalDocument" : 2
},
{
"ColName" : "findValueInArrayWithMultipleCriteriaDemo",
"TotalDocument" : 2
},
{
"ColName" : "firstDocumentDemo",
"TotalDocument" : 3
},
{
"ColName" : "firstElementOfArray",
"TotalDocument" : 2
},
{
"ColName" : "firstItemInArrayToNewFieldDemo",
"TotalDocument" : 2
},
{
"ColName" : "firstLevelArrayDemo",
"TotalDocument" : 2
},
{
"ColName" : "flightInformation",
"TotalDocument" : 2
},
{
"ColName" : "foo2",
"TotalDocument" : 2
},
{
"ColName" : "getAllValue",
"TotalDocument" : 2
},
{
"ColName" : "getDistinctListOfSubDocumentFieldDemo",
"TotalDocument" : 3
},
{
"ColName" : "getDistinctWithSortedDataDemo",
"TotalDocument" : 7
},
{
"ColName" : "getDocuementsByTagsDemo",
"TotalDocument" : 3
},
{
"ColName" : "getError",
"TotalDocument" : 1
},
{
"ColName" : "getFirstElementInArrayDemo",
"TotalDocument" : 3
},
{
"ColName" : "getFirstItemDemo",
"TotalDocument" : 4
},
{
"ColName" : "getIndexDemo",
"TotalDocument" : 1
},
{
"ColName" : "getIndexSizeDemo",
"TotalDocument" : 4
},
{
"ColName" : "getLastNRecordsDemo",
"TotalDocument" : 11
},
{
"ColName" : "getLastXRecordsDemo",
"TotalDocument" : 11
},
{
"ColName" : "getNThElementDemo",
"TotalDocument" : 2
},
{
"ColName" : "getOldestAndYoungestPostDemo",
"TotalDocument" : 4
},
{
"ColName" : "getParticularElementFromArrayDemo",
"TotalDocument" : 2
},
{
"ColName" : "getPartuclarElement",
"TotalDocument" : 1
},
{
"ColName" : "getSizeDemo",
"TotalDocument" : 1
},
{
"ColName" : "getSizeOfArray",
"TotalDocument" : 3
},
{
"ColName" : "gettingHighestValueDemo",
"TotalDocument" : 9
},
{
"ColName" : "groupByDateDemo",
"TotalDocument" : 6
},
{
"ColName" : "handlingAndEmptyDataDemo",
"TotalDocument" : 3
},
{
"ColName" : "hashDemo",
"TotalDocument" : 2
},
{
"ColName" : "hideidDemo",
"TotalDocument" : 3
},
{
"ColName" : "highestNumericValueDemo",
"TotalDocument" : 1
},
{
"ColName" : "highestNumericValueOfAColumnDemo",
"TotalDocument" : 4
},
{
"ColName" : "identifyLastDocuementDemo",
"TotalDocument" : 6
},
{
"ColName" : "improveQueryDemo",
"TotalDocument" : 1
},
{
"ColName" : "incrementInNestedArrayDemo",
"TotalDocument" : 1
},
{
"ColName" : "incrementValueDemo",
"TotalDocument" : 1
},
{
"ColName" : "incrementValueInNestedArrayDemo",
"TotalDocument" : 0
},
{
"ColName" : "indexDemo",
"TotalDocument" : 3
},
{
"ColName" : "indexOptimizationDemo",
"TotalDocument" : 3
},
{
"ColName" : "indexOrQueryDemo",
"TotalDocument" : 0
},
{
"ColName" : "indexTimeDemo",
"TotalDocument" : 0
},
{
"ColName" : "index_Demo",
"TotalDocument" : 2
},
{
"ColName" : "indexingDemo",
"TotalDocument" : 3
},
{
"ColName" : "insertDemo",
"TotalDocument" : 1
},
{
"ColName" : "insertFieldWithCurrentDateDemo",
"TotalDocument" : 3
},
{
"ColName" : "insertIfNotExistsDemo",
"TotalDocument" : 4
},
{
"ColName" : "insertIntegerDemo",
"TotalDocument" : 3
},
{
"ColName" : "insertOneRecordDemo",
"TotalDocument" : 3
},
{
"ColName" : "likeDemo",
"TotalDocument" : 5
},
{
"ColName" : "limitAnArrayDemo",
"TotalDocument" : 1
},
{
"ColName" : "listAllValuesOfCeratinFieldsDemo",
"TotalDocument" : 4
},
{
"ColName" : "loopThroughCollectionDemo",
"TotalDocument" : 4
},
{
"ColName" : "matchBetweenFieldsDemo",
"TotalDocument" : 2
},
{
"ColName" : "mongoExportDemo",
"TotalDocument" : 1
},
{
"ColName" : "multipleElementMatchDemo",
"TotalDocument" : 2
},
{
"ColName" : "multipleIndexesDemo",
"TotalDocument" : 0
},
{
"ColName" : "multipleOrDemo",
"TotalDocument" : 4
},
{
"ColName" : "my-collection",
"TotalDocument" : 1
},
{
"ColName" : "nanDemo",
"TotalDocument" : 4
},
{
"ColName" : "nestedArrayDemo",
"TotalDocument" : 3
},
{
"ColName" : "nestedIndexDemo",
"TotalDocument" : 1
},
{
"ColName" : "nestedObjectDemo",
"TotalDocument" : 1
},
{
"ColName" : "nestedQueryDemo",
"TotalDocument" : 2
},
{
"ColName" : "newProperty",
"TotalDocument" : 2
},
{
"ColName" : "new_Collection",
"TotalDocument" : 3
},
{
"ColName" : "noAutoCommandForIndexDemo",
"TotalDocument" : 4
},
{
"ColName" : "notEqaulToDemo",
"TotalDocument" : 4
},
{
"ColName" : "notEqaultToDemo",
"TotalDocument" : 0
},
{
"ColName" : "notLikeOpeartorDemo",
"TotalDocument" : 5
},
{
"ColName" : "numberofKeysInADocumentDemo",
"TotalDocument" : 1
},
{
"ColName" : "objectInAnArrayDemo",
"TotalDocument" : 2
},
{
"ColName" : "objectidToStringDemo",
"TotalDocument" : 4
},
{
"ColName" : "onlyInsertIfValueIsUniqueDemo",
"TotalDocument" : 4
},
{
"ColName" : "orConditionDemo",
"TotalDocument" : 6
},
{
"ColName" : "orDemo",
"TotalDocument" : 6
},
{
"ColName" : "orderDocsDemo",
"TotalDocument" : 7
},
{
"ColName" : "paginationDemo",
"TotalDocument" : 5
},
{
"ColName" : "performRegex",
"TotalDocument" : 2
},
{
"ColName" : "preventObjectIdDemo",
"TotalDocument" : 1
},
{
"ColName" : "priceStoredAsStringDemo",
"TotalDocument" : 8
},
{
"ColName" : "priceStoredDemo",
"TotalDocument" : 7
},
{
"ColName" : "pullAndAddToSetDemo",
"TotalDocument" : 1
},
{
"ColName" : "pushObjectDemo",
"TotalDocument" : 1
},
{
"ColName" : "queryArrayElementsDemo",
"TotalDocument" : 3
},
{
"ColName" : "queryByKeyDemo",
"TotalDocument" : 1
},
{
"ColName" : "queryBySubFieldDemo",
"TotalDocument" : 2
},
{
"ColName" : "queryForBooleanFieldsDemo",
"TotalDocument" : 5
},
{
"ColName" : "queryInSameDocumentsDemo",
"TotalDocument" : 2
},
{
"ColName" : "queryLengthDemo",
"TotalDocument" : 5
},
{
"ColName" : "queryToEmbeddedDocument",
"TotalDocument" : 1
},
{
"ColName" : "queryingMongoDbCaseInsensitiveDemo",
"TotalDocument" : 4
},
{
"ColName" : "readSpecificKeyValueDemo",
"TotalDocument" : 1
},
{
"ColName" : "regExpOnIntegerDemo",
"TotalDocument" : 5
},
{
"ColName" : "regexSearchDemo",
"TotalDocument" : 5
},
{
"ColName" : "removeAllDocumentsExceptOneDemo",
"TotalDocument" : 1
},
{
"ColName" : "removeArrayDemo",
"TotalDocument" : 1
},
{
"ColName" : "removeArrayElement",
"TotalDocument" : 1
},
{
"ColName" : "removeArrayElementByItsIndexDemo",
"TotalDocument" : 1
},
{
"ColName" : "removeArrayElements",
"TotalDocument" : 1
},
{
"ColName" : "removeDocumentOnBasisOfId",
"TotalDocument" : 4
},
{
"ColName" : "removeDocumentsExceptOneFromCollection",
"TotalDocument" : 1
},
{
"ColName" : "removeDuplicateDocumentDemo",
"TotalDocument" : 4
},
{
"ColName" : "removeDuplicateDocuments",
"TotalDocument" : 3
},
{
"ColName" : "removeDuplicatesDemo",
"TotalDocument" : 1
},
{
"ColName" : "removeElementFromDoublyNestedArrayDemo",
"TotalDocument" : 2
},
{
"ColName" : "removeFieldCompletlyDemo",
"TotalDocument" : 3
},
{
"ColName" : "removeIdDemo",
"TotalDocument" : 4
},
{
"ColName" : "removeMultipleDocumentsDemo",
"TotalDocument" : 3
},
{
"ColName" : "removeObject",
"TotalDocument" : 1
},
{
"ColName" : "removeRecordDemo",
"TotalDocument" : 5
},
{
"ColName" : "removingidElementDemo",
"TotalDocument" : 5
},
{
"ColName" : "renameFieldDemo",
"TotalDocument" : 5
},
{
"ColName" : "renameIdDemo",
"TotalDocument" : 3
},
{
"ColName" : "renamingColumnNameDemo",
"TotalDocument" : 3
},
{
"ColName" : "replaceSpecificArrayValueDemo",
"TotalDocument" : 1
},
{
"ColName" : "retrieveDocumentsWithEndsWithParticularCharacterDemo",
"TotalDocument" : 5
},
{
"ColName" : "retrieveFirstDocumentDemo",
"TotalDocument" : 4
},
{
"ColName" : "retrieveValueFromAKeyDemo",
"TotalDocument" : 3
},
{
"ColName" : "retunFieldInFindDemo",
"TotalDocument" : 4
},
{
"ColName" : "returnOnlyValueOfFieldDemo",
"TotalDocument" : 4
},
{
"ColName" : "returnQueryFromDate",
"TotalDocument" : 4
},
{
"ColName" : "reverseRegexDemo",
"TotalDocument" : 2
},
{
"ColName" : "s",
"TotalDocument" : 2
},
{
"ColName" : "saveStudentInformation",
"TotalDocument" : 4
},
{
"ColName" : "searchArrayDemo",
"TotalDocument" : 2
},
{
"ColName" : "searchByPropertyName",
"TotalDocument" : 5
},
{
"ColName" : "searchDocumentDemo",
"TotalDocument" : 10
},
{
"ColName" : "searchDocumentWithSpecialCharactersDemo",
"TotalDocument" : 4
},
{
"ColName" : "searchForNestedKeysDemo",
"TotalDocument" : 3
},
{
"ColName" : "searchMultipleFieldsDemo",
"TotalDocument" : 3
},
{
"ColName" : "secondDocumentDemo",
"TotalDocument" : 3
},
{
"ColName" : "selectFieldAsAnotherNameDemo",
"TotalDocument" : 4
},
{
"ColName" : "selectInWhereIdDemo",
"TotalDocument" : 6
},
{
"ColName" : "selectMongoDBDocumentsWithSomeCondition",
"TotalDocument" : 7
},
{
"ColName" : "selectRecordsHavingKeyDemo",
"TotalDocument" : 4
},
{
"ColName" : "selectSingleFieldDemo",
"TotalDocument" : 12
},
{
"ColName" : "setMaxDemo",
"TotalDocument" : 0
},
{
"ColName" : "singleFieldDemo",
"TotalDocument" : 4
},
{
"ColName" : "singlePropertyIdDemo",
"TotalDocument" : 5
},
{
"ColName" : "sortDemo",
"TotalDocument" : 6
},
{
"ColName" : "sortInnerArrayDemo",
"TotalDocument" : 1
},
{
"ColName" : "sortingDemo",
"TotalDocument" : 8
},
{
"ColName" : "sourceCollection",
"TotalDocument" : 2
},
{
"ColName" : "sqlLikeDemo",
"TotalDocument" : 7
},
{
"ColName" : "storeQueryResultDemo",
"TotalDocument" : 4
},
{
"ColName" : "stringFieldLengthDemo",
"TotalDocument" : 7
},
{
"ColName" : "stringToDateDataTypeDemo",
"TotalDocument" : 3
},
{
"ColName" : "stringToObjectIdDemo",
"TotalDocument" : 1
},
{
"ColName" : "subsetOfAnArrayDemo",
"TotalDocument" : 1
},
{
"ColName" : "test.js",
"TotalDocument" : 1
},
{
"ColName" : "toLowerDemo",
"TotalDocument" : 4
},
{
"ColName" : "topLevelDocumentDemo",
"TotalDocument" : 1
},
{
"ColName" : "translateDefinitionDemo",
"TotalDocument" : 5
},
{
"ColName" : "twoRandomDocumentDemo",
"TotalDocument" : 6
},
{
"ColName" : "twoSeparateArraysDemo",
"TotalDocument" : 3
},
{
"ColName" : "unconditionalUpdatesDemo",
"TotalDocument" : 4
},
{
"ColName" : "uniqueArrayDemo",
"TotalDocument" : 4
},
{
"ColName" : "uniqueIndexOnArrayDemo",
"TotalDocument" : 3
},
{
"ColName" : "unprettyJsonDemo",
"TotalDocument" : 2
},
{
"ColName" : "unsetAnAttributeDemo",
"TotalDocument" : 1
},
{
"ColName" : "unwindOperatorDemo",
"TotalDocument" : 1
},
{
"ColName" : "updateDemo",
"TotalDocument" : 3
},
{
"ColName" : "updateExactField",
"TotalDocument" : 1
},
{
"ColName" : "updateIdDemo",
"TotalDocument" : 3
},
{
"ColName" : "updateListOfKeyValuesDemo",
"TotalDocument" : 1
},
{
"ColName" : "updateManyDocumentsDemo",
"TotalDocument" : 4
},
{
"ColName" : "updateNestedValueDemo",
"TotalDocument" : 1
},
{
"ColName" : "updateObjects",
"TotalDocument" : 1
},
{
"ColName" : "updateOnlySpecificFieldDemo",
"TotalDocument" : 3
},
{
"ColName" : "updatingEmbeddedDocumentPropertyDemo",
"TotalDocument" : 2
},
{
"ColName" : "userStatus",
"TotalDocument" : 5
}
]