Mongo statement accumulation

Db.collection.stat ()-View table results

Db.collection.find ({ipad:/ ^ 10.42 / {) .pretty ()-View the IPAD field of IPAD that starts with 10.42 (ends with 10.42 $)

Db.collection.find ({ipad:/ ^ 10.42 /}, {vipad:1.ipad:1,id:0})-the first {condition}, non-id field: 1 (display), _ id:0 (not shown)

Db.collection.find () .limit (n)-limits the output of several rows of records

Db.collection.find ({"aa": {"$nin": [PDB,CDB]}})-conditions for querying related fields not in

Db.collection.find ({aa.sid: "cdb01"})-aa field is a [collection of small documents]-[sid: "cdb01", hostname: ""....]

Db.collection.remove ({ipad:/ ^ 10.42 /})-delete specific condition records, delete all without conditions

Db.collection.drop ()-delete the entire document collection

Db.vipad.renameCollection (vipad1)-the table name has been changed from VIPAD to VIPAD1

Db.collection.update ({ipad:/ ^ 10.42 /}, {$set: {isUser: "true"}}, {multi:true})-update the value of the field isuser according to the condition. Multi:true means that all records that meet the condition are updated. The first entry is updated without this parameter value by default.

Db.getCollection ('vipad') .update ({}, {$rename: {"dg01": "dg02"}}, {multi:true})

-multi:true adds fields to the entire table, of course, it can also be written as false,true.

Db.vipad.update ({}, {$set: {aa: ""}}, false,true)-added the field aa, which is empty by default. Instead, delete the field with $unset.

Db.aaa.distinct ("nmid", {"class": 3})-- remove weight

DBQuery.shellBatchSize = 100;-type it for more setting

Batch update: version: "8.7-abc"-update to version: "8.7"

Var collection = 'test';// collection name

Var cnt=0

DB [collection]. Find (). ForEach (function (doc) {

DB [collection] .update ({_ id:doc._id}

{$set: {version:doc.version.replace (/-abc$/,'')}}, false,true)

Cnt=cnt+1

});

Print (cnt)