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SQL (Structured Query Language)

SQL (Structured Query Language). SQL Query （前提）. 假设存在以下三张表. Student. Course. SC. SQL Query. 单表查询 多表查询 案例. 单表查询 — 查询指定列. 查询全体学生的学号，姓名 查询全体学生的姓名和出生年份. 单表查询 所有列. 单表查询 列别名. 查询选修了课程的学生编号. Select Sno from SC; 如何去掉重复结果？. 查询选修了课程的学生编号. Select distinct Sno from SC;. Where 条件过滤.

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SQL (Structured Query Language)

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  1. SQL (Structured Query Language)

  2. SQL Query （前提） 假设存在以下三张表

  3. Student

  4. Course

  5. SC

  6. SQL Query • 单表查询 • 多表查询 • 案例

  7. 单表查询—查询指定列 • 查询全体学生的学号，姓名 • 查询全体学生的姓名和出生年份

  8. 单表查询 所有列

  9. 单表查询列别名

  10. 查询选修了课程的学生编号 Select Sno from SC; 如何去掉重复结果？

  11. 查询选修了课程的学生编号 Select distinct Sno from SC;

  12. Where 条件过滤

  13. Where 查询计算机系（CS）所有学生

  14. Where • 查询年龄20岁以下的学生

  15. Where • 查询有成绩不及格的学生 • 查询所有成绩不及格的学生？？？

  16. Where • 查询年龄在20~23之间的学生编号，学生姓名

  17. Where • 查询信息系(IS)，数学系(MA)，计算机科学系(CS)学生的学生编号和性别

  18. Where 模糊查询 like

  19. Where 模糊查询 like • 如果查询条件中没有包含通配符，like可以用= 代替

  20. Where Like Escape

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