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- db.collection.deleteMany()
db.collection.deleteMany()¶
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Definition¶
-
db.collection.
deleteMany
()¶ Removes all documents that match the
filter
from a collection.db.collection.deleteMany( <filter>, { writeConcern: <document>, collation: <document> } )
Parameter Type Description filter
document Specifies deletion criteria using query operators.
To delete all documents in a collection, pass in an empty document (
{ }
).writeConcern
document Optional. A document expressing the write concern. Omit to use the default write concern. collation
document Optional.
Specifies the collation to use for the operation.
Collation allows users to specify language-specific rules for string comparison, such as rules for lettercase and accent marks.
The collation option has the following syntax:
collation: { locale: <string>, caseLevel: <boolean>, caseFirst: <string>, strength: <int>, numericOrdering: <boolean>, alternate: <string>, maxVariable: <string>, backwards: <boolean> }
When specifying collation, the
locale
field is mandatory; all other collation fields are optional. For descriptions of the fields, see Collation Document.If the collation is unspecified but the collection has a default collation (see
db.createCollection()
), the operation uses the collation specified for the collection.If no collation is specified for the collection or for the operations, MongoDB uses the simple binary comparison used in prior versions for string comparisons.
You cannot specify multiple collations for an operation. For example, you cannot specify different collations per field, or if performing a find with a sort, you cannot use one collation for the find and another for the sort.
New in version 3.4.
Returns: A document containing: - A boolean
acknowledged
astrue
if the operation ran with write concern orfalse
if write concern was disabled
deletedCount
containing the number of deleted documents
- A boolean
Behavior¶
Capped Collections¶
deleteMany()
throws a WriteError
exception
if used on a capped collection. To remove all documents from a capped
collection, use db.collection.drop()
instead.
Delete a Single Document¶
To delete a single document, use db.collection.deleteOne()
instead.
Alternatively, use a field that is a part of a unique index such as
_id
.
Examples¶
Delete Multiple Documents¶
The orders
collection has documents with the following structure:
{
_id: ObjectId("563237a41a4d68582c2509da"),
stock: "Brent Crude Futures",
qty: 250,
type: "buy-limit",
limit: 48.90,
creationts: ISODate("2015-11-01T12:30:15Z"),
expiryts: ISODate("2015-11-01T12:35:15Z"),
client: "Crude Traders Inc."
}
The following operation deletes all documents where client : "Crude Traders
Inc."
:
try {
db.orders.deleteMany( { "client" : "Crude Traders Inc." } );
} catch (e) {
print (e);
}
The operation returns:
{ "acknowledged" : true, "deletedCount" : 10 }
The following operation deletes all documents where stock : "Brent Crude
Futures"
and limit
is greater than 48.88
:
try {
db.orders.deleteMany( { "stock" : "Brent Crude Futures", "limit" : { $gt : 48.88 } } );
} catch (e) {
print (e);
}
The operation returns:
{ "acknowledged" : true, "deletedCount" : 8 }
deleteMany() with Write Concern¶
Given a three member replica set, the following operation specifies a
w
of majority
and wtimeout
of 100
:
try {
db.orders.deleteMany(
{ "client" : "Crude Traders Inc." },
{ w : "majority", wtimeout : 100 }
);
} catch (e) {
print (e);
}
If the acknowledgement takes longer than the wtimeout
limit, the following
exception is thrown:
WriteConcernError({
"code" : 64,
"errInfo" : {
"wtimeout" : true
},
"errmsg" : "waiting for replication timed out"
})
Specify Collation¶
New in version 3.4.
Collation allows users to specify language-specific rules for string comparison, such as rules for lettercase and accent marks.
A collection myColl
has the following documents:
{ _id: 1, category: "café", status: "A" }
{ _id: 2, category: "cafe", status: "a" }
{ _id: 3, category: "cafE", status: "a" }
The following operation includes the collation option:
db.myColl.deleteMany(
{ category: "cafe", status: "A" },
{ collation: { locale: "fr", strength: 1 } }
)