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单选题 在对UPDATE或DELETE语句使用WHERE子句前,应该先用( )进行测试,保证它过滤的是正确的记录,以防编写的WHERE子句不正确
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时间：2026-04-07 10:58:25
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题目1Match the English words to the correct Chinese
A. 第1组 1. desktop 2. keyboard 3. memory 4. monitor 5. battery 6. hard drive 7. speaker 8. gigabyte 9. specification 10. laptopB. 第2组 A. 硬盘驱动器 B. 电池 C. 显示器 D. 千兆字节 E. 键盘 F. 笔记本电脑 G. 扬声器 H. (一般用复数)规格说明 I. 台式电脑 J. 存储量
题目2填空题
Complete the sentences with words or the expression from these words. battery memory hard drive laptop specification monitor speaker gigabyte desktop keyboard 1. This machine demands high __________. 2. The __________ and mouse send your input to the operating system. 3. The heart __________ shows low levels of conciousness. 4. This radio needs two __________. 5. Even though we say __________ that really means billion bytes. 6. This mobile has got 16 gigs of __________. 7. He prefers __________ to laptops. 8. The __________ is a bit low so that I can't hear the voice clearly. 9. She used to work at her __________ until 4 in the morning. 10. If the problem still occurs, your __________ may be broken题目3单选题
在对UPDATE或DELETE语句使用WHERE子句前,应该先用( )进行测试,保证它过滤的是正确的记录,以防编写的WHERE子句不正确A. INSERTB. SETC. SELECTD. HELP
题目4单选题
下列选项中,用于将user表中name字段改username,但数据类型保持不变的是A. ALTER TABLE user CHANGE name usernameB. ALTER TABLE user CHANGE name username VARCHAR(20)C. ALTER TABLE user MODIFY name username VARCHAR(20)D. ALTER TABLE user MODIFY name username
题目5单选题
在MySQL中,如何进行数据的增删改查操作A. INSERT、DELETE、UPDATE和SELECT语句B. CREATE、DROP、ALTER和TRUNCATE语句C. COMMIT、ROLLBACK和SAVEPOINT语句D. GRANT、REVOKE和FLUSH语句
题目6单选题
下面哪个命令可以更新"customers"表中ID为1的记录的"email"字段为"jane@example.com"A. UPDATE customers SET email = 'jane@example.com' WHERE id = 1B. UPDATE customers (email = 'jane@example.com') WHERE id = 1C. UPDATE customers (id = 1, email = 'jane@example.com')D. UPDATE customers SET email = 'jane@example.com' AND id = 1
题目7单选题
下面哪个命令可以从"customers"表中删除ID为1的记录A. DELETE FROM customers WHERE id = 1B. DELETE customers WHERE id = 1C. DELETE customers (id = 1)D. DELETE customers (id = 1) FROM customers
题目8单选题
如何向名为`employees`的表中插入一条新的记录,其中`id`为1,`name`为"John"A. INSERT INTO employees (1, "John")B. INSERT INTO employees (id, name) VALUES (1, "John")C. INSERT INTO employees SET id="1", name="John"D. INSERT INTO employees (id="1", name="John")
题目9单选题
如何从名为`employees`的表中删除`id`值为1的记录A. DELETE FROM employees WHERE id = 1B. DELETE * FROM employees WHERE id = 1C. DELETE employees WHERE id = 1D. TRUNCATE TABLE employees WHERE id = 1
题目10多选题
当使用INSERT语句向数据表中插入数据时,哪些数据类型的字段的插入值需要用单引号A. 日期B. 数值C. 货币D. 文本
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