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81 lines
2.3 KiB
Markdown
81 lines
2.3 KiB
Markdown
---
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toc_priority: 32
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toc_title: SQLite
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---
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# SQLite {#sqlite}
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允许连接到[SQLite](https://www.sqlite.org/index.html)数据库，并支持ClickHouse和SQLite交换数据， 执行 `INSERT` 和 `SELECT` 查询。
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## 创建一个数据库 {#creating-a-database}
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``` sql
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CREATE DATABASE sqlite_database
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ENGINE = SQLite('db_path')
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```
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**引擎参数**
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- `db_path` — SQLite 数据库文件的路径.
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## 数据类型的支持 {#data_types-support}
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| SQLite | ClickHouse |
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|---------------|---------------------------------------------------------|
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| INTEGER | [Int32](../../sql-reference/data-types/int-uint.md) |
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| REAL | [Float32](../../sql-reference/data-types/float.md) |
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| TEXT | [String](../../sql-reference/data-types/string.md) |
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| BLOB | [String](../../sql-reference/data-types/string.md) |
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## 技术细节和建议 {#specifics-and-recommendations}
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SQLite将整个数据库(定义、表、索引和数据本身)存储为主机上的单个跨平台文件。在写入过程中，SQLite会锁定整个数据库文件，因此写入操作是顺序执行的。读操作可以是多任务的。
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SQLite不需要服务管理(如启动脚本)或基于`GRANT`和密码的访问控制。访问控制是通过授予数据库文件本身的文件系统权限来处理的。
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## 使用示例 {#usage-example}
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数据库在ClickHouse，连接到SQLite:
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``` sql
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CREATE DATABASE sqlite_db ENGINE = SQLite('sqlite.db');
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SHOW TABLES FROM sqlite_db;
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```
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``` text
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┌──name───┐
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│ table1 │
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│ table2 │
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└─────────┘
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```
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展示数据表中的内容:
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``` sql
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SELECT * FROM sqlite_db.table1;
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```
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``` text
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┌─col1──┬─col2─┐
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│ line1 │ 1 │
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│ line2 │ 2 │
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│ line3 │ 3 │
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└───────┴──────┘
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```
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从ClickHouse表插入数据到SQLite表:
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``` sql
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CREATE TABLE clickhouse_table(`col1` String,`col2` Int16) ENGINE = MergeTree() ORDER BY col2;
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INSERT INTO clickhouse_table VALUES ('text',10);
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INSERT INTO sqlite_db.table1 SELECT * FROM clickhouse_table;
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SELECT * FROM sqlite_db.table1;
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```
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``` text
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┌─col1──┬─col2─┐
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│ line1 │ 1 │
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│ line2 │ 2 │
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│ line3 │ 3 │
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│ text │ 10 │
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└───────┴──────┘
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```
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