IMongoCollection
的 UpdateMany
方法的第二个参数是 UpdateDefinition<T>
,PipelineUpdateDefinition 是其派生类之一。目前还不支持表达式树,但可以利用 BsonDocument
类:
IMongoCollection<BsonDocument> col = ...;
var pipeline = new EmptyPipelineDefinition<BsonDocument>()
.AppendStage("{ $addFields : { " +
"status : 'Modified'," +
"comments: [ '$misc1', '$misc2' ]," +
"lastUpdate: '$$NOW' " +
"} }",
BsonDocumentSerializer.Instance)
.AppendStage("{ $project : { 'misc1':0, 'misc2':0 } }",
BsonDocumentSerializer.Instance);
col.UpdateMany(new BsonDocument(), pipeline);
执行以下命令(从MongoDB驱动程序跟踪):
"updates" : [
{
"q" : { },
"u" : [
{ "$addFields" : { "status" : "Modified", "comments" : ["$misc1", "$misc2"], "lastUpdate" : "$$NOW" } },
{ "$project" : { "misc1" : 0, "misc2" : 0 } }],
"multi" : true }
}
]