在电商平台数据库中的商品表设计时，“商品名”字段最好选择（）类型。A、textB、char（n）C、varchar（n）D、nvarchar（n）
在电商平台数据库中的商品表设计时，“商品名”字段最好选择（）类型。
- A、text
- B、char（n）
- C、varchar（n）
- D、nvarchar（n）
相关考题：
（1）将考生文件夹下的自由表“商品”添加到数据库"DB1”中。（2）为表“商品”插入一条记录（“08000203”，“眼镜”，“00000008”）。（3）删除表“商品”中编码为“08000131”的记录。（4）修改表“商品”的字段，增加一个字段“单价，N（8，2）”。将（2）（3）（4）所用到的SQL，语句保存到“result.txt”中。
请编写一个函数char *fun(char *s，int n)。函数fun()的功能是将字符串s中的字符“循环左移”n位。例如，输入“ABCDE”，则循环左移2位应输出“CDEAB”，输入“1234567”，循环左移3位应输出“4567123”。注意：部分源程序已存在文件PROC13.cpp中。请勿修改主函数和其他函数中的任何内容，仅在函数fun()的花括号中填写若干语句。文件PROC13.cpp的内容如下：//PROC13.cppinclude ＜iostream＞include ＜string＞using namespace std；char *fun(char *s，int n)；int main(){char str[81]；int n；cout＜＜"Enter a string(less than 80 char)\n”；cin＞＞str；cout＜＜"\n Enter n："；cin＞＞n；if(n＞strlen(str)){cout＜＜"\n Data overflow"；return 0；}cout＜＜"The result is: "＜＜fun(str，n)＜＜end1；return 0；}char *fun(char*s，int n){//* * * * * *}
从商品库的商品表1中查询出比所有商品单价的平均值要高的所有商品记录。提示:在where子句中使用子查询，在子查询中求单价的平均值所采用的函数为avg(单价)。假设使用名称为AAA的数据库，它包括Students(学号char (8)，姓名varchar (8)，年龄int，专业varchar (20)，入学日期DateTime)和Score(学号char (8)，课程名varchar (10)，成绩numeric (5,2))两张表。
Visual FoxPro有如下数据库表stock．dbf，是7月30日沪深股市的收盘情况，请根据此表，完成下题：将stock表中增加一个新字段“交易量”，字段类型是数值型，宽度为8，应使用SQL语句（ ）。A. ALTER stock ALTER交易量N(8)B. ALTER TABLE stock交易量N(8)C. ALTER TABLE stock ADD交易量N(8)D. ALTER TABLE stock交易量WTIH N(8)
以下n变量赋值必须进行强制类型转换的是( )。A．int n；n=100+10；B．int n；n=100F+10；C．int n；short m=10；n=100+m；D．int n；short m=10；char s=2；n=s+m；
利用查询设计器设计查询时，下列叙述中错误的是（）A、在设计多表查询时，必须设置两个表之间的联接类型，默认的联接类型是内联接B、在选择一个排序字段时，系统默认的排序方式为升序C、在“杂项”中设置查询结果的记录范围时，可以选择前N条记录或最后N条记录D、所选的分组字段可以不是查询输出字段
Given the following requirements: Create a table to contain employee data, with a unique numeric identifier automatically assigned when a row is added, has an EDLEVEL column that permits only the values 'C', 'H' and 'N', and permits inserts only when a corresponding value for the employee's department exists in the DEPARTMENT table. Which of the following CREATE statements will successfully create this table?（）A、CREATE TABLE emp ( empno SMALLINT NEXTVAL GENERATED ALWAYS AS IDENTITY, firstname VARCHAR(30) NOT NULL, lastname VARCHAR(30) NOT NULL, workdept CHAR(3) NOT NULL, edlevel CHAR(1), PRIMARY KEY emp_pk (empno), FOREIGN KEY emp_workdept_fk ON (workdept) REFERENCES department (deptno), CHECK edlevel_ck VALUES (edlevel IN ('C','H','N')), );B、CREATE TABLE emp ( empno SMALLINT NOT NULL GENERATED BY DEFAULT AS IDENTITY, firstname VARCHAR(30) NOT NULL, lastname VARCHAR(30) NOT NULL, workdept CHAR(3), edlevel CHAR(1), CONSTRAINT emp_pk PRIMARY KEY (empno), CONSTRAINT emp_workdept_fk FOREIGN KEY (workdept) REFERENCES department (deptno), CONSTRAINT edlevel_ck CHECK edlevel VALUES ('C','H','N') );C、CREATE TABLE emp ( empno SMALLINT NEXTVAL GENERATED BY DEFAULT AS IDENTITY, firstname VARCHAR(30) NOT NULL, lastname VARCHAR(30) NOT NULL, workdept CHAR(3) NOT NULL, edlevel CHAR(1) CHECK IN ('C','H','N')), CONSTRAINT emp_pk PRIMARY KEY (empno), CONSTRAINT emp_workdept_fk FOREIGN KEY department (deptno) REFERENCES (workdept) );D、CREATE TABLE emp ( empno SMALLINT NOT NULL GENERATED BY DEFAULT AS IDENTITY, firstname VARCHAR(30) NOT NULL, lastname VARCHAR(30) NOT NULL, workdept CHAR(3), edlevel CHAR(1), CONSTRAINT emp_pk PRIMARY KEY (empno), CONSTRAINT emp_workdept_fk FOREIGN KEY (workdept) REFERENCES department (deptno), CONSTRAINT edlevel_ck CHECK (edlevel IN ('C','H','N')) );
单选题Given the following requirements: Create a table to contain employee data, with a unique numeric identifier automatically assigned when a row is added, has an EDLEVEL column that permits only the values 'C', 'H' and 'N', and permits inserts only when a corresponding value for the employee's department exists in the DEPARTMENT table. Which of the following CREATE statements will successfully create this table?（）ACREATE TABLE emp ( empno SMALLINT NEXTVAL GENERATED ALWAYS AS IDENTITY, firstname VARCHAR(30) NOT NULL, lastname VARCHAR(30) NOT NULL, workdept CHAR(3) NOT NULL, edlevel CHAR(1), PRIMARY KEY emp_pk (empno), FOREIGN KEY emp_workdept_fk ON (workdept) REFERENCES department (deptno), CHECK edlevel_ck VALUES (edlevel IN ('C','H','N')), );BCREATE TABLE emp ( empno SMALLINT NOT NULL GENERATED BY DEFAULT AS IDENTITY, firstname VARCHAR(30) NOT NULL, lastname VARCHAR(30) NOT NULL, workdept CHAR(3), edlevel CHAR(1), CONSTRAINT emp_pk PRIMARY KEY (empno), CONSTRAINT emp_workdept_fk FOREIGN KEY (workdept) REFERENCES department (deptno), CONSTRAINT edlevel_ck CHECK edlevel VALUES ('C','H','N') );CCREATE TABLE emp ( empno SMALLINT NEXTVAL GENERATED BY DEFAULT AS IDENTITY, firstname VARCHAR(30) NOT NULL, lastname VARCHAR(30) NOT NULL, workdept CHAR(3) NOT NULL, edlevel CHAR(1) CHECK IN ('C','H','N')), CONSTRAINT emp_pk PRIMARY KEY (empno), CONSTRAINT emp_workdept_fk FOREIGN KEY department (deptno) REFERENCES (workdept) );DCREATE TABLE emp ( empno SMALLINT NOT NULL GENERATED BY DEFAULT AS IDENTITY, firstname VARCHAR(30) NOT NULL, lastname VARCHAR(30) NOT NULL, workdept CHAR(3), edlevel CHAR(1), CONSTRAINT emp_pk PRIMARY KEY (empno), CONSTRAINT emp_workdept_fk FOREIGN KEY (workdept) REFERENCES department (deptno), CONSTRAINT edlevel_ck CHECK (edlevel IN ('C','H','N')) );
单选题在电商平台数据库中的商品表设计时，“商品图片”字段存放图片的路径信息，最好选择（）类型。AimageBtextCnvarchar（n）Ddatetime