$sql="SELECT count(*) as pcount FROM news" 和$sql = "UPDATE article SET这句是什么意思?

SQL >select count(*) from Teacher where teacherCode=? and teacherPassword=? java.sql.SQLException:SQL >select count(*) from Teacher where teacherCode=? and teacherPassword=?java.sql.SQLException: Can not issue executeUpdate() for SELECTsat com.mysql. $sql=SELECT count(*) as pcount FROM news 和$sql = UPDATE article SET这句是什么意思? select id,name from student where id in ( select id from score having count(id)>=2 );以上这段语句有没语法错误.SQL语句 sql语句的用法：select as-->>select count(*) as count from table;记录总数保存在count中了,在jsp中这个count怎么用呢,也是就说怎样把这个count的值取出来.直接 int c = count;行吗?或者别的 SQL语句理解 select * from B where (select count(1) as num from A where A.ID = B.ID) = 0select * from B where (select count(1) as num from A where A.ID = B.ID) = 0请问如何理解,为什么 可以在B表中 排除A表的数据 select a.* from test a where 1 > (select count(*) from test where name = a.name and val > a.val )sql语句,按name分组显示最大的val值的字段,不明白具体意思, sql函数,select count(A.abc) as sum from A left join B on A.id=B.id where A.abc='1' group by A.abc结果是 sum 234怎么求count(A.abc) as sum 的总数. SQL的GROUP BY错误SELECT SUM(ADMIN_ENTERED)FROM STATEGROUP BY YEAR_ENTEREDHAVING COUNT(YEAR_ENYERED)=MAX(COUNT(YEAR_ENTERED))系统提示：：ERROR at line 4:ORA-00935:group function is nested too deeply 这是表格：CREATE TABLE STATE(STATE_NAM select count(*) from table1 select count(*) from table2 select count(*) from table3我从table1 table2 table3 中 找数据的条数怎样一下子用一条sql语句 算出TABLE1 TABLE2 TABLE3 记录的总和? select count和select count的区别 请问sql=select * from 招聘信息 order by id sql=select * from x where Min>2 and max if (dt.Rows.Count > 0)求注释求每行代码的注释,protected void InitData(){string id = Request[ID].ToString();try{string sql = select * from TB_MeiShi where ID= + id;DataTable dt = DBHelper.GetDataSet(sql).Tables[0];//执行sql语句从数 ds.Tables[0].Rows.Count > 1 private void button2_Click_1(object sender,EventArgs e){DataSet ds = new DataSet();string consqlserver = Data Source=.;Initial Catalog=留言板;Integrated Security=SSPI;string sql = SELECT * FROM liuyan;SqlConnection select Count(0) from MbrMember where 1=1Count(0)where 1=1 select count(*)count 什么意思和select * 有什么区别 select count(*) from 怎么使用 select count(1) from emp