if object_id('student')is not null drop table student
go
CREATE TABLE student(
s_no nchar(8) PRIMARY KEY,
s_name nchar(8)NOT NULL,
s_sex nchar(2) CHECK(s_sex = N'男' OR s_sex = N'女'),
s_birthday smalldatetime CHECK(s_birthday>='1970-1-1' AND s_birthday<='2000-1-1'),
s_speciality nvarchar(50)DEFAULT N'计算机软件与理论',
s_avgrade numeric(3,1) CHECK(s_avgrade >= 0 AND s_avgrade <= 100),
s_dept nvarchar(50) DEFAULT N'计算机科学系'
);
注：以上约束，默认等将在后续讲解
数据表的结构信息一般可以在系统目录中查询(information_schema.columns)包括表名，字段名，长度，类型等等
SELECT
table_name ,
column_name,
isnull(column_default,'') default_value,
is_nullable,
data_type, isnull(isnull(isnull(character_maximum_length,numeric_precision),datetime_precision),1)length
from information_schema.columns
WHERE table_name='student'
添加数据
INSERT INTO student Values('20060201',N'李好',N'男', '1987-1-1', N'计算机应 用技术', 94.5, N'计算机系');
INSERT INTO student Values('20060202',N'王丫',N'女', '1987-2-23', N'计算机软件与理论', 88.8, N'计算机系');
INSERT INTO student Values('20060203',N'王智高',N'男', '1986-12-25', N'网络编程', 85.8, N'信息工程系');
INSERT INTO student Values('20060204',N'赵刚',N'男', '1988-7-1', N'网络编程', 77.8, N'信息工程系');
INSERT INTO student Values('20060205',N'贾志',N'男', '1985-9-18', N'计算机应用技术', 45.0, N'计算机系');
INSERT INTO student Values('20060206',N'丽思',N'女', '1984-8-1', N'计算机应 用技术', 61.3, N'计算机系');
INSERT I
