您要对EMPLOYEES表的FIRST_NAME和LAST_NAME列创建一个组合索引。以下哪条语句将完成此任务()
第1题:
已知下列员工关系表。Employees对该表的工资属性和完整性约束为:2000≤工资≤5000 现将如下2个操作组织为事务T,操作1先执行,操作2后执行。 操作1:INSERT INTO Employees VALUES(‘03650’,‘研发’,‘4600’) 操作2:UPDATE Employees SET工资=工资1.2 WHERE部门=‘市场OR部门=研发’事务T执行完毕后,关系表Employees.的数据是
第2题:
数据集中的数据表名称是不区分大小写的,ds.Tables("Employees")和ds.Tables("employees")是同一个表。
第3题:
“雇员”表在LAST_NAME列上有一个名为LN_IDX的索引。您要将此索引更改为FIRST_NAME列的索引。以下哪条SQL语句将实现此操作()
第4题:
有个员工表employees,该表中有职务列。你想检查哪些员工的信息中没有填写职务一栏,应该使用()。
第5题:
您在“雇员”表的一个子集上创建了名为EMPLOYEES_VIEW的视图。用户AUDREY需要使用此视图创建报表。只有您和Audrey具有此视图的访问权限。应执行下列哪项操作()
第6题:
ALTER TABLE salary ADD CONSTRAINT fk_employee_id_01 FOREIGN KEY(employee_id)REFERENCES employees(employee_id)
ALTER TABLE salary ADD CONSTRAINT fk_employee_id_ FOREIGN KEY BETWEEN salary(employee_id)AND employees(employee_id)
ALTER TABLE salary FOREIGN KEY CONSTRAINT fk_employee_id_REFERENCES employees(employee_id)
ALTER TABLE salary ADD CONSTRAINT fk_employee_id_FOREIGN KEY salary(employee_id)=employees(employee_id)
第7题:
INSERT INTO employees VALUES ( NULL, ‘John’,‘Smith’);
INSERT INTO employees( first_name, last_name) VALUES(‘John’,‘Smith’);
INSERT INTO employees VALUES (‘1000’,‘John’,NULL);
INSERT INTO employees(first_name,last_name, employee_id) VALUES ( 1000, ‘John’,‘Smith’);
INSERT INTO employees (employee_id) VALUES (1000);
INSERT INTO employees (employee_id, first_name, last_name) VALUES ( 1000, ‘John’,‘’);
第8题:
You get an error because of a primary key violation.
The data and structure of the EMPLOYEES table are deleted.
The data in the EMPLOYEES table is deleted but not the structure.
You get an error because the statement is not syntactically correct.
第9题:
UPDATE employees SET first_name = 'John' SET last_name = 'Smith' WHERE employee_id = 180;
UPDATE employees SET first_name = 'John', SET last_name = 'Smoth' WHERE employee_id = 180;
UPDATE employee SET first_name = 'John' AND last_name = 'Smith' WHERE employee_id = 180;
UPDATE employee SET first_name = 'John', last_name = 'Smith' WHERE employee_id = 180;
第10题:
INSERT INTO employees VALUES (NULL, 'JOHN','Smith');
INSERT INTO employees( first_name, last_name) VALUES ('JOHN','Smith');
INSERT INTO employees VALUES ('1000','JOHN','NULL');
INSERT INTO employees(first_name,last_name, employee_id) VALUES ('1000, 'john','Smith');
INSERT INTO employees (employee_id) VALUES (1000);
INSERT INTO employees (employee_id, first_name, last_name) VALUES ( 1000, 'john',);
第11题:
此语句会创建一个基于函数的索引
因为语法错误,此语句将失败
该语句将创建一个组合唯一索引
该语句将创建一个组合非唯一索引
第12题:
对
错
第13题:
数据库benet中有个员工表employees,该表中有职务列,可以实现检查哪些员工的信息中没有填写职务一栏,应该使用子句()
第14题:
数据集中的数据表名称是区分大小写的,ds.Tables("Employees")和ds.Tables("employees")不是同一个表。
第15题:
在执行语句SELECT department_id FROM employees,departments WHERE employees.department_id= departments.department_id;时报错,原因是()。
第16题:
“雇员”表包含以下列: EMPLOYEE_ID NOT NULL, Primary Key SSNUM NOT NULL, Unique LAST_NAME VARCHAR2(25) FIRST_NAME VARCHAR2(25) DEPARTMENT_ID NUMBER 部门表中 DEPARTMENT_ID 列的外键 SALARY NUMBER(8,2) 如果执行以下语句: CREATE INDEX emp_name_idx ON employees(last_name, first_name); 以下哪个说法是的()
第17题:
对
错
第18题:
INSERT INTO employees VALUES (NULL, 'John', 'smith');
INSERT INTO employees (first_name, last_name) VALUES ('John', 'smith');
INSERT INTO employees VALUES ('1000, 'John', 'smith');
INSERT INTO employees (first_name, last_name, employee_id) VALUES (1000, 'John', 'smith');
INSERT INTO employees (employee_id) VALUES (1000);
INSERT INTO employees ( employee_id, first_name, last_name, ) VALUES (1000, 'John','');
第19题:
UPDATE employees SET first_name = 'John' SET last_name = 'Smith' WHERE employee_id = 180;
UPDATE employees SET first_name = 'John', SET last_name = 'Smoth' WHERE employee_id = 180;
UPDATE employee SET first_name = 'John' AND last_name = 'Smith' WHERE employee_id = 180;
UPDATE employee SET first_name = 'John', last_name = 'Smith' WHERE employee_id = 180;
第20题:
alter table authors add first_name not null
alter table authors modify first_name not null
alter table authors alter first_name not null
alter table authors drop first_name not null
第21题:
UPDATE employees SET first_name = 'John' SET last_name ='Smith' WHERE employee_id = 180;
UPDATE employees SET first_name = 'John', SET last_name ='Smith' WHERE employee_id = 180;
UPDATE employees SET first_name = 'John' AND last_name ='Smith' WHERE employee_id = 180;
UPDATE employees SET first_name = 'John', last_name ='Smith' WHERE employee_id = 180;
第22题:
INSERT INTO employees (employee_id, first_name, last_name, hire_date) VALUES (1000, 'John', 'smith','01/01/01);
INSERT INTO employees(employee_id, first_name, last_name, hire_date) VALUES (1000, 'John', 'smith','01 january 01');
INSERT INTO employees(employee_id, first_name, last_name, Hire_date) VALUES (1000, 'John', 'smith', To_ date ('01/01/01));
INSERT INTO employees(employee_id, first_name, last_name, hire_date) VALUES (1000, 'John', 'smith','01-Jan-01');
第23题:
CREATE INDEX NAME _IDX (first_name, last_name);
CREATE INDEX NAME _IDX (first_name, AND last_name)
CREATE INDEX NAME_IDX ON (First_name, last_name);
CREATE INDEX NAME_IDX ON employees (First_name, AND last_name);
CREATE INDEX NAME_IDX ON employees (First_name, last_name);
CREATE INDEX NAME_IDX FOR employees (First_name, last_name);