The MongoCursorException class

Introduction

Caused by accessing a cursor incorrectly or a error receiving a reply.

If there is an error receiving a reply, there will be a more specific error message to help diagnose the problem. As it is a bit programmatically awkward to parse an exception message, there is also an error code associated with each cause of the exception.

• cannot modify cursor after beginning iteration

  Code: 0

  You are calling a method that sets up the query after executing the query. Reset the cursor and try again.

• Various send errors

  Code: 1

  Could not send the query to the database. Make sure the database is still up and the network is okay.

• cursor not found

  Code: 2

  The driver was trying to fetch more results from the database, but the database did not have a record of the query. This usually means that the cursor timed out on the server side: after a few minutes of inactivity, the database will kill a cursor (see MongoCursor::immortal() for information on preventing this).

• Various database errors

  Code: 4

  The database errored out on the query. The error message should be fairly self-explanatory, but you can check the database log for details.

• couldn't get response header

  Code: 3

  The driver could not fetch a reply header from the database, so it gave up. Check if the database is still up and the network is connected and try the query again.

• no db response

  Code: 5

  This may not even be an error, for example, the database command "shutdown" returns no response. However, if you were expecting a response, this means the database didn't give one.

• no db response

  Code: 5

• bad response length: %d, max: %d, did the db assert?

  Code: 6

  This means that the database said that its response was greater than 4Mb or less than 0. Generally, a number greater than 5Mb should be reported to the developers as a potential database bug (max response length is 4Mb). A response of less than 0 often means a database assertion occured.

• incomplete header/response

  Code: 7

  Highly unusual. Occurs if the database response started out correctly, but broke off in the middle. Probably indicates a network problem.

• error getting database response: errstr

  WSA error getting database response: errstr

  "errstr" is an io error reported directly from the C socket subsystem. On Windows, the error message is prefixed with "WSA".

• error getting database response: <various>

  Code: 8

  Something went wrong at the socket layer. This will return the error message from the C socket library.

• couldn't find a response

  Code: 9

  If the response was cached and now cannot be located.

• various

  Code: 10

  No code given by the database.

• E11000 duplicate key error index: foo.bar.$X dup key: { /* ... */ }

  Code: 11000

  Database error for duplicate keys.

Class synopsis