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62 lines
1.5 KiB
Markdown
62 lines
1.5 KiB
Markdown
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---
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machine_translated: true
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machine_translated_rev: b111334d6614a02564cf32f379679e9ff970d9b1
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toc_priority: 46
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toc_title: GenerateRandom
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---
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# Generaterandom {#table_engines-generate}
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GenerateRandom表引擎为给定的表架构生成随机数据。
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使用示例:
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- 在测试中使用填充可重复的大表。
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- 为模糊测试生成随机输入。
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## 在ClickHouse服务器中的使用 {#usage-in-clickhouse-server}
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``` sql
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ENGINE = GenerateRandom(random_seed, max_string_length, max_array_length)
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```
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该 `max_array_length` 和 `max_string_length` 参数指定所有的最大长度
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数组列和字符串相应地在生成的数据中。
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生成表引擎仅支持 `SELECT` 查询。
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它支持所有 [数据类型](../../../sql_reference/data_types/index.md) 可以存储在一个表中，除了 `LowCardinality` 和 `AggregateFunction`.
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**示例:**
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**1.** 设置 `generate_engine_table` 表:
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``` sql
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CREATE TABLE generate_engine_table (name String, value UInt32) ENGINE = GenerateRandom(1, 5, 3)
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```
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**2.** 查询数据:
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``` sql
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SELECT * FROM generate_engine_table LIMIT 3
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```
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``` text
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┌─name─┬──────value─┐
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│ c4xJ │ 1412771199 │
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│ r │ 1791099446 │
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│ 7#$ │ 124312908 │
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└──────┴────────────┘
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```
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## 实施细节 {#details-of-implementation}
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- 不支持:
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- `ALTER`
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- `SELECT ... SAMPLE`
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- `INSERT`
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- 指数
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- 复制
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[原始文章](https://clickhouse.tech/docs/en/operations/table_engines/generate/) <!--hide-->
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