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57 lines
1.1 KiB
Markdown
57 lines
1.1 KiB
Markdown
---
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slug: /zh/engines/table-engines/integrations/mongodb
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sidebar_position: 5
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sidebar_label: MongoDB
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---
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# MongoDB {#mongodb}
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MongoDB 引擎是只读表引擎，允许从远程 MongoDB 集合中读取数据(`SELECT`查询)。引擎只支持非嵌套的数据类型。不支持 `INSERT` 查询。
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## 创建一张表 {#creating-a-table}
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``` sql
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CREATE TABLE [IF NOT EXISTS] [db.]table_name
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(
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name1 [type1],
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name2 [type2],
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...
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) ENGINE = MongoDB(host:port, database, collection, user, password);
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```
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**引擎参数**
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- `host:port` — MongoDB 服务器地址.
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- `database` — 数据库名称.
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- `collection` — 集合名称.
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- `user` — MongoDB 用户.
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- `password` — 用户密码.
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## 用法示例 {#usage-example}
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ClickHouse 中的表，从 MongoDB 集合中读取数据:
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``` text
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CREATE TABLE mongo_table
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(
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key UInt64,
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data String
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) ENGINE = MongoDB('mongo1:27017', 'test', 'simple_table', 'testuser', 'clickhouse');
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```
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查询:
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``` sql
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SELECT COUNT() FROM mongo_table;
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```
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``` text
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┌─count()─┐
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│ 4 │
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└─────────┘
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```
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