术语和概念
| SQL 术语和概念 | MongoDB 术语和概念 |
|---|---|
| database | database**(opens new window)** |
| table | collection**(opens new window)** |
| row | document (opens new window)或 BSON**(opens new window)** |
| column | field**(opens new window)** |
| index | index**(opens new window)** |
| table joins | $lookup (opens new window)、嵌入式文档 |
| primary key | primary key**(opens new window)** MongoDB 中自动设置主键为 _id (opens new window)字段 |
| aggregation (e.g. group by) | aggregation pipeline 参考 SQL to Aggregation Mapping Chart (opens new window). |
| SELECT INTO NEW_TABLE | $out(opens new window)参考 SQL to Aggregation Mapping Chart**(opens new window)** |
| MERGE INTO TABLE | $merge (opens new window)(MongoDB 4.2 开始支持)参考 SQL to Aggregation Mapping Chart (opens new window). |
| UNION ALL | $unionWith (opens new window)(MongoDB 4.4 开始支持) |
| transactions | transactions |
下一节：MongoDB 的聚合框架以数据处理管道（Pipeline）的概念为模型。