51 lines
1.8 KiB
Markdown
51 lines
1.8 KiB
Markdown
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---
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title: SQL Server Convert Function
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localeTitle: SQL Server转换函数
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---
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## SQL Server转换函数
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从一种数据类型转换为另一种数据类型。
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### 句法
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`CONVERT (_New Data Type, Expression, Style_)`
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* **新数据类型:**也要转换的新数据类型。例如:nvarchar,integer,decimal,date
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* **表达式:**要转换的数据。
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* **风格:**格式。例如:样式110是美国日期格式mm-dd-yyyy
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### 示例:将十进制数转换为整数
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`SELECT CONVERT(INT, 23.456) as IntegerNumber`
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![将十进制数转换为整数](https://user-images.githubusercontent.com/12566249/31314884-6c94db4a-ac57-11e7-842f-710fad511131.png)
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注意:结果被截断。
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### 示例:将字符串转换为日期
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`SELECT CONVERT(DATE, '20161030') as Date`
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![将字符串转换为日期类型](https://user-images.githubusercontent.com/12566249/31314912-c25bbb52-ac57-11e7-880d-6d81041b1728.png)
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### 示例:将十进制转换为字符串
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`SELECT CONVERT(nvarchar, 20.123) as StringData`
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![将小数转换为字符串](https://user-images.githubusercontent.com/12566249/31314923-fb04e410-ac57-11e7-9646-94061e1f0ec2.png)
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### 示例:将整数转换为十进制数
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`SELECT CONVERT(DECIMAL (15,3), 13) as DecimalNumber`
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![将整数转换为十进制数](https://user-images.githubusercontent.com/12566249/31314932-1c8668ca-ac58-11e7-8cee-4d57fc523704.png)
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### 示例:在美国日期样式中将字符串转换为日期格式
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`SELECT CONVERT(DATE, '20171030' , 110) To_USA_DateFormat`
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![将字符串转换为美国日期样式的日期格式](https://user-images.githubusercontent.com/12566249/31314937-35155d06-ac58-11e7-9d5d-823b66c41d0d.png)
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### 更多信息:
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* 有关转换功能的信息: [Microsoft](https://docs.microsoft.com/en-us/sql/t-sql/functions/cast-and-convert-transact-sql)
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