37 lines
929 B
Transact-SQL
37 lines
929 B
Transact-SQL
Use Homework250417
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Go
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CREATE TABLE Employee(
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EmployeeID INT PRIMARY KEY,
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Name NVARCHAR(20),
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Age INT,
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Salary INT,
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);
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Go
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/* 删除员工表信息时，如果员工个数<5，不允许删除员工信息，
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记录下企图删除员工信息的行为 */
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CREATE TABLE DelEmployeeAttempt(
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AttemptID INT PRIMARY KEY IDENTITY(1,1),
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EmployeeID INT,
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AttemptTime DATETIME DEFAULT GETDATE(),
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);
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Go
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CREATE TRIGGER trg_DelEmployee
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ON Employee
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INSTEAD OF DELETE
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AS
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BEGIN
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DECLARE @EmployeeCount INT;
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SELECT @EmployeeCount = COUNT(*) FROM Employee;
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IF @EmployeeCount < 5
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BEGIN
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INSERT INTO DelEmployeeAttempt (EmployeeID)
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SELECT EmployeeID FROM DELETED;
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RAISERROR(N'少于5名员工，无法删除', 16, 1);
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END
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ELSE
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BEGIN
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DELETE FROM Employee WHERE EmployeeID IN (SELECT EmployeeID FROM DELETED);
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PRINT(N'删除员工信息成功');
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END
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END;
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Go |