我在练习mongodb命令的时候，这段怎么也无法通过，一直报错：
SyntaxError: identifier starts immediately after numeric literal
db.mycol.insertMany([{ _id: ObjectId(7df78ad8902c) title: 'MongoDB Overview', description: 'MongoDB is no sql database', by_user: 'runoob.com', url: 'http://www.runoob.com', tags: ['mongodb', 'database', 'NoSQL'], likes: 100 }, { _id: ObjectId(7df78ad8902d) title: 'NoSQL Overview', description: 'No sql database is very fast', by_user: 'runoob.com', url: 'http://www.runoob.com', tags: ['mongodb', 'database', 'NoSQL'], likes: 10 }, { _id: ObjectId(7df78ad8902e) title: 'Neo4j Overview', description: 'Neo4j is no sql database', by_user: 'Neo4j', url: 'http://www.neo4j.com', tags: ['neo4j', 'database', 'NoSQL'], likes: 750 }])后来，把这段里面的三个_id字段去掉就执行成功了
db.mycol.insertMany([{ title: 'MongoDB Overview', description: 'MongoDB is no sql database', by_user: 'runoob.com', url: 'http://www.runoob.com', tags: ['mongodb', 'database', 'NoSQL'], likes: 100 }, { title: 'NoSQL Overview', description: 'No sql database is very fast', by_user: 'runoob.com', url: 'http://www.runoob.com', tags: ['mongodb', 'database', 'NoSQL'], likes: 10 }, { title: 'Neo4j Overview', description: 'Neo4j is no sql database', by_user: 'Neo4j', url: 'http://www.neo4j.com', tags: ['neo4j', 'database', 'NoSQL'], likes: 750 }])解析：
原来是_id字段有三处错误
第一：该字段最后没有加逗号，
第二：ObjectId的参数应该是字符串应该加 “”
第三：_id对字符串似乎对长度有要求，24位如：5ce742df49b868781061e446，多一个或者少一个不能执行通过，
报错如下： [js] Error: invalid object id: length
所以正确的是应该是：
db.auto.insertMany([{ _id: ObjectId("5ce742df49b868781061e446"), title: 'MongoDB Overview', description: 'MongoDB is no sql database', by_user: 'runoob.com', url: 'http://www.runoob.com', tags: ['mongodb', 'database', 'NoSQL'], likes: 100 }, { _id: ObjectId("5ce742df49b868781061e447"), title: 'NoSQL Overview', description: 'No sql database is very fast', by_user: 'runoob.com', url: 'http://www.runoob.com', tags: ['mongodb', 'database', 'NoSQL'], likes: 10 }, { _id: ObjectId("5ce742df49b868781061e448"), title: 'Neo4j Overview', description: 'Neo4j is no sql database', by_user: 'Neo4j', url: 'http://www.neo4j.com', tags: ['neo4j', 'database', 'NoSQL'], likes: 750 }])
