SQL语句示例及解析试题及答案
姓名:____________________
一、单项选择题(每题2分,共10题)
1.下列SQL语句中,用于创建名为“Students”的表,包含“ID”(学号)、“Name”(姓名)和“Age”(年龄)字段的正确语句是:
A.CREATETABLEStudents(IDINT,NameVARCHAR(50),AgeINT);
B.CREATETABLEStudentsIDINT,NameVARCHAR(50),AgeINT);
C.CREATETABLEStudents(IDINT,NameVARCHAR(50),AgeINT,);
D.CREATETABLEStudents(IDINT,NameVARCHAR(50),AgeINT);
2.要删除名为“Employees”的表中“Department”字段,以下哪个SQL语句是正确的?
A.ALTERTABLEEmployeesDROPCOLUMNDepartment;
B.ALTERTABLEEmployeesREMOVECOLUMNDepartment;
C.ALTERTABLEEmployeesDELETECOLUMNDepartment;
D.ALTERTABLEEmployeesDROPDepartment;
3.以下哪个SQL语句可以用来查询“Students”表中年龄大于18岁的所有学生?
A.SELECT*FROMStudentsWHEREAge18;
B.SELECT*FROMStudentsWHEREAge18;
C.SELECT*FROMStudentsWHEREAge=18;
D.SELECT*FROMStudentsWHEREAge=18;
4.在SQL中,使用“LIKE”运算符来搜索模式匹配的语句是:
A.WHERENameLIKE%John%;
B.WHEREName=%John%;
C.WHEREName=LIKE%John%;
D.WHERENameLIKE%John;
5.以下哪个SQL语句可以用来计算“Students”表中所有学生的平均年龄?
A.SELECTAVG(Age)FROMStudents;
B.SELECTSUM(Age)FROMStudents;
C.SELECTMIN(Age)FROMStudents;
D.SELECTMAX(Age)FROMStudents;
6.以下哪个SQL语句可以用来将“Students”表中所有学生的年龄加1?
A.UPDATEStudentsSETAge=Age+1;
B.UPDATEStudentsSETAge=(Age+1);
C.UPDATEStudentsSETAge+=1;
D.UPDATEStudentsSETAge+1=Age;
7.要在“Employees”表中插入一条新记录,包括“ID”(员工ID)、“Name”(姓名)和“Department”(部门),以下哪个SQL语句是正确的?
A.INSERTINTOEmployees(ID,Name,Department)VALUES(1,JohnDoe,HR);
B.INSERTINTOEmployeesID,Name,DepartmentVALUES(1,JohnDoe,HR);
C.INSERTINTOEmployees(ID,Name,Department)VALUES(1,JohnDoe,HR);
D.INSERTINTOEmployees(ID,Name,Department)VALUES(1,JohnDoe,HR);
8.以下哪个SQL语句可以用来删除“Students”表中年龄为20岁的所有记录?
A.DELETEFROMStudentsWHEREAge=20;
B.DELETEFROMStudentsWHEREAge!=20;
C.DELETEFROMStudentsWHEREAge=20ANDAge!=20;
D.DELETEFROMStudentsWHEREAge!=20ORAge=20;
9.要将“Students”表中的“Name”字段更新为“NewName”,以下哪个S