46 lines
840 B
Markdown
46 lines
840 B
Markdown
# 模式系统
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BaraDB 使用 schema-first 设计，支持类型继承和自动迁移。
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## 定义类型
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```nim
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import barabadb/schema/schema
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var s = newSchema()
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let person = newType("Person")
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person.addProperty("name", "str", required = true)
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person.addProperty("age", "int32")
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s.addType("default", person)
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```
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## 类型继承
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```nim
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let employee = newType("Employee")
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employee.setBases(@["Person"])
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employee.addProperty("department", "str")
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s.addType("default", employee)
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```
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## 模式操作
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### Diff
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```nim
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let diff = s.diff(oldSchema, newSchema)
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```
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## 属性类型
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| 类型 | 描述 |
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|------|------|
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| `str` | 字符串 |
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| `int32` | 32 位整数 |
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| `int64` | 64 位整数 |
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| `float32` | 32 位浮点数 |
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| `float64` | 64 位浮点数 |
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| `bool` | 布尔值 |
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| `datetime` | 日期/时间 |
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| `bytes` | 二进制数据 | |