Mongodb 此对象已经是运算符表达式,并且可以';不能用作文档表达式
在mongodb中执行以下命令时出错:Mongodb 此对象已经是运算符表达式,并且可以';不能用作文档表达式,mongodb,Mongodb,在mongodb中执行以下命令时出错: db.trans.aggregate( [ { $match: {"cno":89}}, { $group: { _id: [ $dateToString: { format: "%Y-%m-%d", date: "$transactiondate" },types:"$type"], count: { $sum: 1 } } }]) 我想按交易日期和类型分组 错误是: assert: command failed: { "ok"
db.trans.aggregate(
[
{ $match: {"cno":89}},
{ $group: { _id: [ $dateToString: { format: "%Y-%m-%d", date: "$transactiondate" },types:"$type"], count: { $sum: 1 } } }])
我想按交易日期和类型分组
错误是:
assert: command failed: {
"ok" : 0,
"errmsg" : "this object is already an operator expression, and can't be used as a document expression (at 'types')",
"code" : 15990
} : aggregate failed_getErrorWithCode@src/mongo/shell/utils.js:25:13
doassert@src/mongo/shell/assert.js:16:14
assert.commandWorked@src/mongo/shell/assert.js:370:5
DBCollection.prototype.aggregate@src/mongo/shell/collection.js:1319:5
@(shell):1:1
2017-10-24T15:38:35.498+0530 E QUERY [thread1] Error: command failed: {
"ok" : 0,
"errmsg" : "this object is already an operator expression, and can't be used as a document expression (at 'types')",
"code" : 15990
} : aggregate failed :
_getErrorWithCode@src/mongo/shell/utils.js:25:13
doassert@src/mongo/shell/assert.js:16:14
assert.commandWorked@src/mongo/shell/assert.js:370:5
DBCollection.prototype.aggregate@src/mongo/shell/collection.js:1319:5
@(shell):1:1
{$group:{{u id:{“date”:{$dateToString:{格式:'%Y-%m-%d',日期:$transactiondate'}},类型:$type'},计数:{$sum:1}}
。几个基本语法错误。如果你只是把改正的地方和你做错的地方进行比较,那就容易多了。