数据库中学生表和课程表如下：内连接sql语句：select a.studentName,a.studentAge,b.courseName from student a inner join course b on a.studentID=b.studentID查询结果如下：查询的结果是以从表cou... Read More
数据库中学生表和课程表如下：左连接sql语句：select a.studentName,a.studentAge,b.courseName from student a left join course b //left join 左连接，以左表为主on a.studentID=b.studentI... Read More
先看如下程序：class Program { static void Main(string[] args) { int x = 0; int y = 0; int i = 2; ... Read More