數(shù)據(jù)庫sql練習(xí)題
當(dāng)提供一些數(shù)據(jù)庫的代碼題并提供解答,請注意以下代碼題僅適用于概念理解和練習(xí),可能需要根據(jù)具體數(shù)據(jù)庫系統(tǒng)進(jìn)行適當(dāng)修改。 題目1: 創(chuàng)建一個名為"Students"的表,包含以下列:StudentID(主鍵,整數(shù)),F(xiàn)irstName(字符串),LastName(字符串),Age(整數(shù)),Major(字符串)。 解答1: ```sql CREATE TABLE Students ( ?StudentID INT PRIMARY KEY, ?FirstName VARCHAR(50), ?LastName VARCHAR(50), ?Age INT, ?Major VARCHAR(50) ); ``` 題目2: 在"Students"表中插入一條記錄,StudentID為1,F(xiàn)irstName為"John",LastName為"Doe",Age為20,Major為"Computer Science"。 解答2: ```sql INSERT INTO Students (StudentID, FirstName, LastName, Age, Major) VALUES (1, 'John', 'Doe', 20, 'Computer Science'); ``` 題目3: 查詢"Students"表中所有記錄。 解答3: ```sql SELECT * FROM Students; ``` 題目4: 更新"Students"表中StudentID為1的記錄,將Major改為"Information Technology"。 解答4: ```sql UPDATE Students SET Major = 'Information Technology' WHERE StudentID = 1; ``` 題目5: 刪除"Students"表中StudentID為1的記錄。 解答5: ```sql DELETE FROM Students WHERE StudentID = 1; ``` 題目6: 創(chuàng)建一個名為"Courses"的表,包含以下列:CourseID(主鍵,整數(shù)),CourseName(字符串),Instructor(字符串),Credits(整數(shù))。 解答6: ```sql CREATE TABLE Courses ( ?CourseID INT PRIMARY KEY, ?CourseName VARCHAR(50), ?Instructor VARCHAR(50), ?Credits INT ); ``` 題目7: 在"Courses"表中插入兩條記錄,CourseID分別為1和2,CourseName分別為"Mathematics"和"Physics",Instructor分別為"Smith"和"Johnson",Credits分別為3和4。 解答7: ```sql INSERT INTO Courses (CourseID, CourseName, Instructor, Credits) VALUES (1, 'Mathematics', 'Smith', 3), (2, 'Physics', 'Johnson', 4); ``` 題目8: 查詢"Courses"表中所有記錄。 解答8: ```sql SELECT * FROM Courses; ``` 題目9: 更新"Courses"表中CourseID為1的記錄,將Instructor改為"Brown"。 解答9: ```sql UPDATE Courses SET Instructor = 'Brown' WHERE CourseID = 1; ``` 題目10: 刪除"Courses"表中CourseID為2的記錄。 解答10: ```sql DELETE FROM Courses WHERE CourseID = 2; ``` 題目11: 創(chuàng)建一個名為"Orders"的表,包含以下列:OrderID(主鍵,整數(shù)),CustomerID(整數(shù)),OrderDate(日期),TotalAmount(浮點(diǎn)數(shù))。 解答11: ```sql CREATE TABLE Orders ( ?OrderID INT PRIMARY KEY, ?CustomerID INT, ?OrderDate DATE, ?TotalAmount FLOAT ); ``` 12: 在"Orders"表中插入一條記錄,OrderID為1,CustomerID為101,OrderDate為'2023-06-18',TotalAmount為100.00。 解答12: ```sql INSERT INTO Orders (OrderID, CustomerID, OrderDate, TotalAmount) VALUES (1, 101, '2023-06-18', 100.00); ``` 題目13: 查詢"Orders"表中所有記錄。 解答13: ```sql SELECT * FROM Orders; ``` 題目14: 更新"Orders"表中OrderID為1的記錄,將TotalAmount改為200.00。 解答14: ```sql UPDATE Orders SET TotalAmount = 200.00 WHERE OrderID = 1; ``` 題目15: 刪除"Orders"表中OrderID為1的記錄。 解答15: ```sql DELETE FROM Orders WHERE OrderID = 1; ``` 題目16: 創(chuàng)建一個名為"Customers"的表,包含以下列:CustomerID(主鍵,整數(shù)),F(xiàn)irstName(字符串),LastName(字符串),Email(字符串)。 解答16: ```sql CREATE TABLE Customers ( ?CustomerID INT PRIMARY KEY, ?FirstName VARCHAR(50), ?LastName VARCHAR(50), ?Email VARCHAR(100) ); ``` 題目17: 在"Customers"表中插入一條記錄,CustomerID為101,F(xiàn)irstName為"John",LastName為"Doe",Email為"john.doe@example.com"。 解答17: ```sql INSERT INTO Customers (CustomerID, FirstName, LastName, Email) VALUES (101, 'John', 'Doe', 'john.doe@example.com'); ``` 題目18: 查詢"Customers"表中所有記錄。 解答18: ```sql SELECT * FROM Customers; ``` 題目19: 更新"Customers"表中CustomerID為101的記錄,將Email改為"johndoe@example.com"。 解答19: ```sql UPDATE Customers SET Email = 'johndoe@example.com' WHERE CustomerID = 101; ``` 題目20: 刪除"Customers"表中CustomerID為101的記錄。 解答20: ```sql DELETE FROM Customers WHERE CustomerID = 101; ```