Docs Menu


On this page

  • Definition
  • Behavior
  • Example
db.getLastErrorObj(w, wtimeout, j)

Starting in MongoDB 5.0, db.getLastErrorObj() is deprecated. For more information and alternatives, see Deprecated Wire Protocol Opcodes.

Changed in version 2.6: A new protocol for write operations integrates write concerns with the write operations, eliminating the need for a separate db.getLastErrorObj(). Most write methods now return the status of the write operation, including error information. In previous versions, clients typically used the db.getLastErrorObj() in combination with a write operation to verify that the write succeeded.

The db.getLastErrorObj() can accept the following parameters:

int or string
Optional. The write concern's w value.
Optional. The time limit in milliseconds.
If true, wait for the next journal commit before returning, rather than waiting for a full disk flush. If mongod does not have journaling enabled, this option has no effect. If this option is enabled for a write operation, mongod will wait no more than 1/3 of the current commitIntervalMs before writing data to the journal.

The following example issues a db.getLastErrorObj() operation that verifies that the preceding write operation, issued over the same connection, has propagated to at least two members of the replica set.


If the last error object is a duplicate key error, the method returns a document similar to the following:

"err" : "E11000 duplicate key error collection: test.foobar index: x_1 dup key: { x: 1.0 }",
"ns" : "test.foobar", // New in 4.4
"index" : "x_1", // New in 4.4
"code" : 11000,
"codeName" : "DuplicateKey",
"n" : 0,
"singleShard" : "",
"ok" : 1,
"operationTime" : Timestamp(1584654273, 1),
"$clusterTime" : {
"clusterTime" : Timestamp(1584654274, 1),
"signature" : {
"hash" : BinData(0,"Z3L9FdEIYQ2MwLg6X/4sDWacqzM="),
"keyId" : NumberLong("6806025526243754005")
See also:
Give Feedback
MongoDB logo
© 2021 MongoDB, Inc.


  • Careers
  • Investor Relations
  • Legal Notices
  • Privacy Notices
  • Security Information
  • Trust Center
© 2021 MongoDB, Inc.