网友您好， 请在下方输入框内输入要搜索的题目：
题目内容
（请给出正确答案）
修改SC表中的约束C3使得大学生的年龄在18到40之间的约束为： ALTER TABLE Student ADD CONSTRAINT C3 CHECK（Sage ＜30 and Sage ＞15);
参考答案和解析
B
更多 “修改SC表中的约束C3使得大学生的年龄在18到40之间的约束为： ALTER TABLE Student ADD CONSTRAINT C3 CHECK（Sage ＜30 and Sage ＞15);” 相关考题
考题
在SQL Server 2000中，设有职工表(职工号， 职工名， 电子邮箱)，现要限制电子邮箱的最后几位的取值为“@abc.com”，且“@”前至少有一位字符。下列添加约束的语句正确的是A．ALTER TABLE职工表 ADD CONSTRAINT chk_email CHECK(电子邮箱LIKE '_%@abc.com')B．ALTER TABLE职工表 ADD CONSTRAINT chk_email CHECK(电子邮箱 = '_%@abc.com')C．ALTER TABLE职工表 ADD CONSTRAINT chk_email CHECK(电子邮箱LIKE '_@abc.com')D．ALTER TABLE职工表 ADD CONSTRAINT chk_email CHECK(电子邮箱 = '_@abc.com')
考题
若给出关系Student(S_no，Shame，Sage，S_sex，SD_name，S_add，S_tel)，并用SQL语言定义Student关系如下：CREATE Student(S_no CHAR(6)， Sname CHAR(30)NOT NULL， Sage CHAR(30)， S_sex CHAR(1)， SD_name CHAR(20)， S_add CHAR(30)， S_tel CHAR(20)， PRIMARY KEY(S_no))；采用(41)向Student中插入记录能被正确地执行。A．INSERT INTO Smdent(S_no，Sname，Sage，S_sex，SD_name，S_add，S_tel)VALUES('010456'，'黎敏'，'18'，"，"，"，")B．INSERT INTO Student(S_no，Sname，Sage，S_sex，S_r)name，S_add，S_tel)VALUES('010456'，'黎敏'，'18'，'男'，'计算机学院'，'北京'，'88661200')C．INSERT INTO Student(S_no，Sname，Sage，S_sex，SD_name，S_add，S_tel)VALUES(，'黎敏'，'18'，'F'，'计算机学院'，'北京'，'88661200')D．INSERT INTO Student(S_no，Sname，Sage，S_sex，SD_name，S_add，S_tel)VALUES('010456'，，'18'，'F'，'计算机学院'，'北京'，'88661200')
考题
You need to modify the STUDENTS table to add a primary key on the STUDENT_ID column. The table is currently empty. Which statement accomplishes this task?()
A. ALTER TABLE students ADD PRIMARY KEY _ id;B. ALTER TABLE students ADD CONSTRAINT PRIMARY KEY (student_id);C. ALTER TABLE students ADD CONSTRAINT stud_id_pk PRIMARY KEY student_id;D. ALTER TABLE students ADD CONSTRAINT stud_id_pk PRIMARY KEY (student_id);E. ALTER TABLE students MODIFY CONSTRAINT stud_id_pk PRIMARY KEY (student_id);
考题
Which statement adds a constraint that ensures the CUSTOMER_NAME column of the CUSTOMERS table holds a value?()
A. ALTER TABLE customers ADD CONSTRAINT cust_name_nn CHECK customer_name IS NOT NULL;B. ALTER TABLE customers MODIFY CONSTRAINT cust_name_nn CHECK customer_name IS NOT NULL;C. ALTER TABLE customers MODIFY customer_name CONSTRAINT cust_name_nn NOT NULL;D. ALTER TABLE customers MODIFY customer_name CONSTRAINT cust_name_nn IS NOT NULL;E. ALTER TABLE customers MODIFY name CONSTRAINT cust_name_nn NOT NULL;F. ALTER TABLE customers ADD CONSTRAINT cust_name_nn CHECK customer_name NOT NULL;
考题
根据SQL标准，删除表student中对字段sno的唯一性约束，应该使用下面哪条语句? ()A drop sno from table studentB alter table student drop snoC alter table student drop unique(sno)D alter table student drop sno unique
考题
根据SQL标准，增加一个新的字段sdate到表student中，该字段为可容纳7个字符的定长字符串，下面哪条语句可以参考表述?()A insert into student sdate char(7)B add sdate char(7) to studentC append sdate varchar(7) to table studentD alter table student add sdate varchar(7)E alter table student add sdate char(7)F alter table student modify sdate char(7)
考题
Which statement explicitly names a constraint? ()
A. ALTER TABLE student_grades ADD FOREIGN KEY (student_id) REFERENCES students (student_id);B. ALTER TABLE student_grades ADD CONSTRAINT NAME = student_id_fk FOREIGN KEY (student_id) REFERENCES students (student_id);C. ALTER TABLE student_grades ADD CONSTRAINT student_id_fk FOREIGN KEY (student_id) REFERENCES students (student_id);D. ALTER TABLE student grades ADD NAMED CONSTRAINT student_id_fk FOREIGN KEY (student_id) REFERENCES students (student_id);E. ALTER TABLE student grades ADD NAME student_id_fk FOREIGN KEY (student_id) REFERENCES students (student_id);
考题
当前盘当前目录下有学生管理数据库，其中有数据库表学生.dbf、课程.dbf、选课.dbf，该数据库表的结构如下： 学生(学生号N3，姓名C3，性别C1，年龄N2) 课程(课程号C3，课程名称C3，教师C3) 选课(学生号N3，课程号C3，成绩N3)为“学生”表中的“年龄”字段定义有效性检查及错误信息的是______。A．ALTER TABLE学生ALTER年龄； CHECK年龄＞19 ERROR“年龄应满19岁”B． ALTER TABLE学生 ALTER年龄； SET CHECK年龄＞19 ERROR年龄应满19岁C．ALTER TABLE学生ALTER年龄； SET CHECK年龄＞19 ERROR“年龄应满19岁”D．ALTER TABLE学生ALTER年龄； CHECK年龄＞19 ERROR“年龄应满19岁”
考题
将Student.dbf表中jg字段的名称改为籍贯，如下选项中正确的SQL语句是A）ALTER TABLE student ALTER COLUMN jg TO籍贯B）ALTER TABLE student ADD籍贯C（10）C）ALTER TABLE student RENAME jg TO籍贯D）ALTER TABLE student RENAME jg籍贯
考题
若给出关系Student(S_no, Sname, Sage, S_sex, SD_name, S_add, S_tel)，并用SQL语言定义Student关系如下： CREATE Student(S_no CHAR(6), Sname CHAR(30)NOT NULL, Sage CHAR(30), S_sex CHAR(1), SD_name CHAR(20), S_add CHAR(30), S_tel CHAR(20), PRIMARY KEY(S_no)); 采用(45)向Student中插入记录能被正确地执行。A．INSERT INTO Student(S_no, Sname, Sage, S_sex, SD_name, S_add, S_tel) VALUES('010456', '黎敏', '18', ", ", ", ")B．INSERT INTO Student(S_no, Sname, Sage, S_sex, SD_name, S_add, S_tel) VALUES('010456', '黎敏', '18', '男', '计算机学院', '北京', '88661200')C．INSERT INTO Student(S_no, Sname, Sage, S_sex, SD_name, S_add, S_tel) VALUES(, '黎敏', '18', 'F', '计算机学院', '北京', '88661200')D．INSERT INTO Student(S_no, Sname, Sage, S_sex, SD_name, S_add, S_tel) VALUES('010456', , '18', 'F', '计算机学院', '北京', '88661200')
考题
将Student.dbf表中jg字段的名称改为籍贯，如下选项中正确的SQL语句是( )。A．ALTER TABLE student ALTER COLUMN jg TO 籍贯B．ALTER TABLE student ADD 籍贯 C(10)C．ALTER TABLE student RENAME jg TO 籍贯D．ALTER TABLE student RENAME jg 籍贯
考题
之前已经创建了一个Student的表，Age有数据类型为Int，现在改为smallint应该( )写。A.ALTER TABLE student ALTER COLUMN sage smallintB.ALTER TABLE student ALTER COLUMN age smallintC.ALTER TABLE student ALTER MODIFY age smallintD.ALTER TABLE student MODIFY sage smallint
考题
给student表增加一个“平均成绩”字段(数值型，总宽度6，2位小数)的SQL命令是（ ）。A.ALTER TABLE student ADD平均成绩N(6，2)B.ALTER TABLE student ADD平均成绩D(6，2)C.ALTER TABLE student ADD平均成绩E(6，2)D.ALTER TABLE student ADD平均成绩Y(6，2)
考题
现要利用Student表查询年龄最小的学生姓名和年龄。下列实现此功能的查询语句中，正确的是（）。ASELECT Sname，MIN（Sage） FROM StudentBSELECT Sname，Sage FROM Student WHERE Sage = MIN（Sage）CSELECT TOP 1 Sname，Sage FROM StudentDSELECT TOP 1 Sname，Sage FROM Student ORDER BY Sage
考题
为表TEST中ID列添加主键约束的语法是（）A、ALTER TABLE TEST CHANGE（ ID INT PRIMARY KEY）B、ALTER TABLE TEST ADD（ ID INT PRIMARY KEY）C、ALTER TABLE TEST MODIFY（ ID INT PRIMARY KEY）D、ALTER TABLE TEST ADD CONSTRAINT PK PRIMARY KEY （ID）
考题
您在公司的数据库中成功创建了名为SALARY的表。您现在要通过向引用EMPLOYEES表的匹配列的SALARY表添加FOREIGNKEY约束条件来建立EMPLOYEES表与SALARY表之间的父/子关系。尚未向SALARY表添加任何数据。应执行以下哪条语句（）A、ALTER TABLE salary ADD CONSTRAINT fk_employee_id_01 FOREIGN KEY（employee_id）REFERENCES employees（employee_id）B、ALTER TABLE salary ADD CONSTRAINT fk_employee_id_ FOREIGN KEY BETWEEN salary（employee_id）AND employees（employee_id）C、ALTER TABLE salary FOREIGN KEY CONSTRAINT fk_employee_id_REFERENCES employees（employee_id）D、ALTER TABLE salary ADD CONSTRAINT fk_employee_id_FOREIGN KEY salary（employee_id）=employees（employee_id）
考题
要向雇员表中的部门标识列添加FOREIGNKEY约束条件以引用部门表中的标识列，应该使用哪个语句（）A、ALTER TABLE雇员MODIFY COLUMN dept_id_fk FOREIGN KEY（部门标识）REFERENCES部门（部门标识）B、ALTER TABLE雇员ADD CONSTRAINT dept_id_fk FOREIGNKEY（部门标识）REFERENCES部门（部门标识）C、ALTER TABLE雇员ADD FOREIGN KEY CONSTRAINT dept_id_fk ON（部门标识）REFERENCES部门（部门标识）D、ALTER TABLE雇员ADD FOREIGN KEY 部门（部门标识）REFERENCES（部门标识）
考题
删除PRIMARYKEY约束条件及其所有依赖约束条件的语法是什么（）A、ALTER TABLE table_name DROP CONSTRAINT constraint_name CASCADEB、ALTER TABLE table_name DROP CONSTRAINT FOREIGN KEY CASCADEC、DROP CONSTRAINT table_name（constraint_name）D、ALTER TABLE table_name DROP CONSTRAINT constraint_name
考题
Which statement explicitly names a constraint? （）A、ALTER TABLE student_grades ADD FOREIGN KEY (student_id) REFERENCES students (student_id);B、ALTER TABLE student_grades ADD CONSTRAINT NAME = student_id_fk FOREIGN KEY (student_id) REFERENCES students (student_id);C、ALTER TABLE student_grades ADD CONSTRAINT student_id_fk FOREIGN KEY (student_id) REFERENCES students (student_id);D、ALTER TABLE student grades ADD NAMED CONSTRAINT student_id_fk FOREIGN KEY (student_id) REFERENCES students (student_id);E、ALTER TABLE student grades ADD NAME student_id_fk FOREIGN KEY (student_id) REFERENCES students (student_id);
考题
DEPARTMENT 表包含以下列： DEPT_ID NUMBER, Primary Key DEPT_ABBR VARCHAR2(4) DEPT_NAME VARCHAR2(30) MGR_ID NUMBER EMPLOYEE 表包含以下列： EMPLOYEE_ID NUMBER EMP_LNAME VARCHAR2(25) EMP_FNAME VARCHAR2(25) DEPT_ID NUMBER JOB_ID NUMBER MGR_ID NUMBER SALARY NUMBER(9,2) HIRE_DATE DATE 请评估以下语句： ALTER TABLE employee ADD CONSTRAINT REFERENTIAL (mgr_id) TO department(mgr_id); 是以下哪个说法（）A、ALTER TABLE语句创建从EMPLOYEE表到DEPARTMENT表的引用约束条件B、ALTER TABLE语句创建从DEPARTMENT表到EMPLOYEE表的引用约束条件C、ADD CONSTRAINT子句存在语法错误，因此ALTER TABLE语句将会失败D、ALTER TABLE语句执行成功，但不重新创建引用约束条件
考题
You need to modify the STUDENTS table to add a primary key on the STUDENT_ID column. The table is currently empty.Which statement accomplishes this task?（）A、ALTER TABLE students ADD PRIMARY KEY student_id;B、ALTER TABLE students ADD CONSTRAINT PRIMARY KEY (student _ id);C、ALTER TABLE students ADD CONSTRAINT stud _ id _pk PRIMARY KEY (student _ id);D、ALTER TABLE students MODIFY CONSTRAINT stud _ id _pk PRIMARY KEY (student _ id);
考题
You need to modify the STUDENTS table to add a primary key on the STUDENT_ID column. The table is currently empty. Which statement accomplishes this task?（）A、ALTER TABLE students ADD PRIMARY KEY _ id;B、ALTER TABLE students ADD CONSTRAINT PRIMARY KEY (student_id);C、ALTER TABLE students ADD CONSTRAINT stud_id_pk PRIMARY KEY student_id;D、ALTER TABLE students ADD CONSTRAINT stud_id_pk PRIMARY KEY (student_id);E、ALTER TABLE students MODIFY CONSTRAINT stud_id_pk PRIMARY KEY (student_id);
考题
You need to modify the STUDENTS table to add a primary key on the STUDENT_ID column. The table is currently empty.Which statement accomplishes this task?（）A、ALTER TABLE students ADD PRIMARY KEY student_id;B、ALTER TABLE students ADD CONSTRAINT PRIMARY KEY (student_id);C、ALTER TABLE students ADD CONSTRAINT stud_id_pk PRIMARY KEY student_id;D、ALTER TABLE students ADD CONSTRAINT stud_id_pk PRIMARY KEY (student_id);E、ALTER TABLE students MODIFY CONSTRAINT stud_id_pk PRIMARY KEY (student_id);
考题
单选题现要利用Student表查询年龄最小的学生姓名和年龄。下列实现此功能的查询语句中，正确的是（）。A
SELECT Sname，MIN（Sage） FROM StudentB
SELECT Sname，Sage FROM Student WHERE Sage = MIN（Sage）C
SELECT TOP 1 Sname，Sage FROM StudentD
SELECT TOP 1 Sname，Sage FROM Student ORDER BY Sage
考题
判断题Sage TINYINT CHECK（Sage=22 AND Sage=60）中的变量Sage只能取值在22到60之间。A
对B
错
热门标签
最新试卷