要获取所有数据库的列表,您需要使用以下语法-use admin
db.runCommand({listDatabases: 1});
要获取特定数据库的所有集合名称的列表,您需要使用以下语法-use yourDatabaseName;
db.getCollectionNames();
让我们实现以上语法-
情况1-获取数据库列表> use admin
switched to db admin
> db.runCommand({listDatabases: 1});
这将产生以下输出-{
"databases" : [
{
"name" : "admin",
"sizeOnDisk" : 1675264,
"empty" : false
},
{
"name" : "config",
"sizeOnDisk" : 131072,
"empty" : false
},
{
"name" : "local",
"sizeOnDisk" : 77824,
"empty" : false
},
{
"name" : "main",
"sizeOnDisk" : 184320,
"empty" : false
},
{
"name" : "my",
"sizeOnDisk" : 753664,
"empty" : false
},
{
"name" : "sample",
"sizeOnDisk" : 1286144,
"empty" : false
},
{
"name" : "sampleDemo",
"sizeOnDisk" : 352256,
"empty" : false
},
{
"name" : "studentSearch",
"sizeOnDisk" : 262144,
"empty" : false
},
{
"name" : "test",
"sizeOnDisk" : 15810560,
"empty" : false
},
{
"name" : "university",
"sizeOnDisk" : 229376,
"empty" : false
},
{
"name" : "web",
"sizeOnDisk" : 217088,
"empty" : false
}
],
"totalSize" : 20979712,
"ok" : 1
}
情况2-获取收藏列表
在这里,我们获取数据库“样本”的集合列表> use sample;
switched to db sample
> db.getCollectionNames();
这将产生以下输出-[
"arraySizeErrorDemo",
"basicInformationDemo",
"copyThisCollectionToSampleDatabaseDemo",
"documentWithAParticularFieldValueDemo",
"employee",
"findListOfIdsDemo",
"findMimimumElementInArrayDemo",
"findSubstring",
"getAllRecordsFromSourceCollectionDemo",
"getElementWithMaxIdDemo",
"insertDocumentWithDateDemo",
"internalArraySizeDemo",
"largestDocumentDemo",
"makingStudentInformationClone",
"nestedArrayDemo",
"oppositeAddToSetDemo",
"prettyDemo",
"returnOnlyUniqueValuesDemo",
"selectItemDemo",
"selectWhereInDemo",
"sourceCollection",
"specificFieldDemo",
"studentInformation",
"sumOfValueDemo",
"sumTwoFieldsDemo",
"truncateDemo",
"updateFieldIfValueIsGreaterDemo",
"updateInformation",
"userInformation"
]