39 lines
1.7 KiB
Markdown
39 lines
1.7 KiB
Markdown
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---
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title: SQL Select Statement
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localeTitle: SQL Select语句
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---
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## SQL Select语句
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## 选择和从子句
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查询的SELECT部分通常用于确定要在结果中显示哪些数据列。您还可以应用选项来显示非表格列的数据。
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此示例显示从“student”表和一个计算列中选择的三列。数据库存储学生的studentID，FirstName和LastName。我们可以组合First和Last name列来创建FullName计算列。
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```sql
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select studentID, FirstName, LastName, FirstName + ' ' + LastName as FullName
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from student;
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```
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```text
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+-----------+-------------------+------------+------------------------+
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| studentID | FirstName | LastName | FullName |
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+-----------+-------------------+------------+------------------------+
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| 1 | Monique | Davis | Monique Davis |
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| 2 | Teri | Gutierrez | Teri Gutierrez |
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| 3 | Spencer | Pautier | Spencer Pautier |
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| 4 | Louis | Ramsey | Louis Ramsey |
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| 5 | Alvin | Greene | Alvin Greene |
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| 6 | Sophie | Freeman | Sophie Freeman |
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| 7 | Edgar Frank "Ted" | Codd | Edgar Frank "Ted" Codd |
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| 8 | Donald D. | Chamberlin | Donald D. Chamberlin |
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| 9 | Raymond F. | Boyce | Raymond F. Boyce |
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+-----------+-------------------+------------+------------------------+
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9 rows in set (0.00 sec)
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```
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\*与所有这些SQL事物一样，它们比本入门指南中的内容更多。
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我希望这至少足以让你开始。
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请参阅您的数据库管理员手册，并自己尝试不同的选项。
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