[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"$fOtMeI2rdp90xY-PqL4wRivv-eGeoUuBQco5sTe1V2DU":3},{"answer":4,"createTime":5,"id":6,"options":7,"origin":12,"question":19,"related":20,"source":30,"type":31},[],"2024-05-21 20:37:00",145139777,[8,9,10,11],"SELECT cust_last_name AS Name, cust_credit_limit + 1000as New Credit LimitFROM customers","SELECT cust_last_name Name, cust_credit_limit + 1000"New Credit Limit"FROM customers","SELECT cust_last_name As "Name", cust_credit_limit + 1000AS "New Credit Limit"FROM customers","SELECT INITCAP (cust_last_name) "Name", cust_credit_limit + 1000INITCAP("NEW CREDIT LIMIT")FROM customers",{"count":13,"courseId":14,"courseImg":15,"courseName":16,"workId":17,"workName":18},99,"4097ec18a6093777f05789fe98db4bbb","https:\u002F\u002Ftihai-oss-cloud.itihey.com\u002Fimg\u002F4549d915a9be0f4756b955186e92c18d.png","现代数据库系统","work_35140929","U5-4 After-sales Service","选择最佳答案: 您需要生成一个报告,其中每个客户的信用额度都增加了1000美元.在输出中,客户的姓氏应具有标题名称,增加的信用额度应标记为新信用额度.列标题应该只有每个单词的第一个大写字母. 哪种说法可以满足这个要求",[21,32,41,50,59,68,78,81,90,99],{"answer":22,"createTime":5,"id":23,"options":24,"question":29,"source":30,"type":31},[],145139757,[25,26,27,28],"1","100","200","10","评估下面 CREATE SEQUENCE 声明: CREATE SEQUENCE seq1 START WITH 100 INCREMENT BY 10 MAXVALUE 200 CYCLE ; 这个序列 SEQ1生成的数字已达到最大限制200. 接下来执行如下语句: select nextval('seq1'); 这个SELECT 语句执行结果会是多少","v1",0,{"answer":33,"createTime":5,"id":34,"options":35,"question":40,"source":30,"type":31},[],145139760,[36,37,38,39],"执行失败因为 ON 子句的条件是无效的","它成功执行并显示所需列表","它成功执行但是不显示所需列表","它失败是因为使用的连接类型不正确","选择最佳答案 检查用于创建DEPT和EMP的命令: CREATE TABLE DEPT (DEPTNO int CONSTRAINT PK_DEPT PRIMARY KEY, DNAME varchar(14) , LOC varchar(13) ) ; CREATE TABLE EMP (EMPNO int CONSTRAINT PK_EMP PRIMARY KEY, ENAME varchar(10), JOB varchar(9), MGR int, HIREDATE DATE, SAL int, COMM int, DEPTNO int CONSTRAINT FK_DEPTNO REFERENCES DEPT); 您要生成EMP中不存在的所有deptno的列表. 您执行如下语句: TESTDB=> SELECT d.deptno FROM emp e INNER JOIN dept d ON e.deptno>d.deptno; 上面语句会输出什么结果",{"answer":42,"createTime":5,"id":43,"options":44,"question":49,"source":30,"type":31},[],145139763,[45,46,47,48],"它可以用来通过相等连接和非相等连接访问表中的数据","它可以用于连接具有相同名称和兼容数据类型的列的表","它最多可用于连接三个表","它可以用来限制自然连接中使用的列数","选择最佳答案 关于表连接中的USING子句,哪个语句是正确的",{"answer":51,"createTime":5,"id":52,"options":53,"question":58,"source":30,"type":31},[],145139768,[54,55,56,57],"它会产生错误,因为orderby子句只应出现在复合查询的末尾,即最后一个SELECT语句","它成功执行并按促销类别的降序显示行","它产生了一个错误,因为在ORDER BY子句中不能使用带SET运算符的位置表示法","它成功执行,但忽略ORDER BY子句,因为它不在复合语句的末尾","选择最正确答案 评估下面的SQL语句: SQL> SELECT promo_id, promo_category FROM promotions WHERE promo_category = 'Internet' ORDER BY 2 DESC UNION SELECT promo_id, promo_category FROM promotions WHERE promo_category = 'TV' UNION SELECT promo_id, promo_category FROM promotions WHERE promo_category ='Radio'; 关于上述查询的结果,哪个陈述是正确的",{"answer":60,"createTime":5,"id":61,"options":62,"question":67,"source":30,"type":31},[],145139771,[63,64,65,66],"将=替换为>ALL运算符","将=替换为>ANY运算符","从子查询中删除GROUPBY子句并将其放入主查询中","将=替换为IN运算符","选择最佳答案 检查以下SQL语句: SELECT order_id, product_id, unit_price FROM order_items WHERE unit_price = (SELECT MAX(unit_price) FROM order items GROUP BY order_id); 您想显示每个订单ID的单价最高的产品的产品ID. 在上面的SQL语句中应该做什么修改来实现这一点",{"answer":69,"createTime":5,"id":70,"options":71,"question":77,"source":30,"type":31},[],145139774,[72,73,74,75,76],"EMP_ID列中的主键约束必须有名称,并且只能在表级别定义","约束定义中缺少外键关键字","每个表只能使用一个text","在DEPT_ID列上定义的外键只能在表级别","ENAME列上的NOT NULL约束必须在列级别定义","选择一个: 您执行了以下CREATE TABLE语句,导致了一个错误: testdb=> CREATE TABLE employees2 ( emp_id int PRIMARY KEY, ename VARCHAR(20) , email int UNIQUE, address VARCHAR(500), phone VARCHAR (20), resume text, hire_date timestamp, remarks text, CONSTRAINT ename_nn NOT NULL(ename) ); 找出错误的一个原因",{"answer":79,"createTime":5,"id":6,"options":80,"question":19,"source":30,"type":31},[],[8,9,10,11],{"answer":82,"createTime":5,"id":83,"options":84,"question":89,"source":30,"type":31},[],145139780,[85,86,87,88],"在PostgreSQL数据库中,一个BEGIN开始的事务中,DDL语句(比如TRUNCATE)可以被ROLLBACK","在PostgreSQL数据库中,一个BEGIN开始的事务中,DDL语句(比如TRUNCATE)不可以被ROLLBACK","在Oracle数据库中,一个BEGIN开始的事务中,DDL语句(比如TRUNCATE)可以被ROLLBACK","在Oracle数据库中,一个BEGIN开始的事务中,DDL语句(比如TRUNCATE)不可以被ROLLBACK","下面有关DDL语句描述正确的是",{"answer":91,"createTime":5,"id":92,"options":93,"question":98,"source":30,"type":31},[],145139783,[94,95,96,97],"它忽略空值并为子查询生成的其他值生成输出","它会产生一个错误","它为NULL以及子查询生成的其他值生成输出","它执行,但不返回任何行","评估以下SQL语句: SQL>SELECT ename FROM emp WHERE empno in (SELECT mgr FORM emp); 如果子查询生成的值之一为NULL,那么关于上述查询,哪个语句是真的",{"answer":100,"createTime":5,"id":101,"options":102,"question":107,"source":30,"type":31},[],145139786,[103,104,105,106],"只有将PUBLISHER_ID列名添加到columns列表并且在INSERT语句中并且显式指定NULL时,它才会成功执行","只有在INSERT语句中明确指定NULL时,它才能成功执行","只有将PUBLISHER_ID列名添加到INSERT语句的列列表中时,它才会成功执行","它成功执行,并且插入的行的发布者ID为空","选择最佳答案: 检查创建BOOKS表的命令. testdb=> CREATE TABLE books (book_id CHAR(6) PRIMARY KEY, title VARCHAR(100) NOT NULL, publisher_id VARCHAR(4), author_id VARCHAR(50)); 在表中BOOK_ID值不存在101. 检查SQL语句: testdb=> INSERT INTO books(BOOK_ID, TITLE, AUTHOR_ID) testdb-> VALUES ('101', 'LEARNING SQL', 'Tim Jones'); 哪种说法是正确的"]