These questions include SQL interview questions for freshers and experienced, as well as SQL query interview questions. 1. What is the difference between a primary key and a unique key? 2. What is a constraint, and why use constraints? 3. What is the COALESCE function? 4. What are UNION...
50. What is SQL*plus? What can be done with it? SQL* Plus is a component of Oracle Database. It is basically a command-line tool that allows you to submit SQL queries to the server interactively. We can view the results by running a SELECT query. With SQL*Plus, we can startup an...
具体的SQL脚本可能如下所示：sql WITH DB_CPU AS (SELECT DB_NAME(database_id) AS DatabaseName,SUM(total_worker_time) AS TotalCPU FROM sys.dm_exec_query_stats AS qs CROSS APPLY sys.dm_exec_sql_text(qs.sql_handle) AS sql_text WHERE database_id > 4 GROUP BY DB_NAME(datab...
【题目】sql选择题SELECT TOP 40 PERCENT SName, SAddre ss FROM Students结果返回了20行数据,则这个表有多少行数据 A.40 B.20 C.50 D.100 相关知识点: 试题来源: 解析 【解析】select top 40 PERCENT...是取满足 条件的前40%条记录,,现在只返回了20条说明 表里50条记录 答案选择C 给分吧,呵呵 反馈...
1这句sql语句哪里有语法问题,错误提示说“关键字 'From' 附近有语法错误。”"Select top 50 From Book where bookname like '%"+bookname+"%' order by bookid desc" 2这句sql语句哪里有语法问题,错误提示说“关键字 From 附近有语法错误。”"Select top 50 From Book where bookname like \%"+bookna...
To answer this SQL question, you can think of De Morgan’s law, which says that: Not (A Or B) <=> _Not A And Not B_. What is the equivalent? How could we model that for an SQL query? 36. Given a table of employees and departments, write a query to select the top 3 depart...
In .dump ?table? Command, the databases are dumped in SQL text format.Discuss this Question 50. What does .echo on|off command do?It turns the echo command on It turns the echo command off It turns the echo command on or off None of the above...
Structured Query Language (SQL) goes by that name. It is the language utilised to manipulate databases. The SQL has several categories. TCL DML DDL 28. Explain Polymorphism Having several forms is called polymorphism. Depending on the message or the event occuring, the program's object may beha...
the interviewer. Depending on the circumstances, asking questions during the interview is acceptable, although it's generally more common to hold off on your questions until the end of the interview. That said, you should never hesitate to ask for clarification on a question the interviewer asks...
执行以下sql语句: select top 40 percent sname,saddress from students 结果返回了20行数据,则() A. 表stu