使用数据集访问数据库??? [英] Access Database by using dataset ???

问题描述

myConnect.open();
string myStringCommand ="SELECT序数，codeOfStu，fullName，ST.codeOfClass，CL.nameOfClass来自学生ST，CL类WHERE ST.codeOfClass = CL.codeOfClass和ST.codeOfClass = @SelectedCodeOfClass";
OleDbCommand命令=新的OleDbCommand(myStringCommand，myConnect);
OleDbParameter myParameter =新的OleDbParameter("@ SelectedCodeOfClass"，OleDbType.Integer);
myParameter.Value = SelectedCodeOfClass; //SelectedCodeOfClass是从主函数携带的参数.
myCommand.Parameters.Add(myParameter);
OleDbDataReader myReader = myCommand.ExecuteReader();
.
.
.

现在，我不想再使用连接模型"来访问数据库.我想使用断开模型"来做到这一点.
如果我喜欢这样:
OleDbDataAdapter adap =新的OleDbDataAdapter(从表名中选择*"，con);
数据集ds = new Dataset();
adap.fill(ds);

我收到的东西是一个数据表，涉及所有学生.我不想读取数据库中的所有学生信息.我只想阅读学生的所属类别的信息(codeOfClass)

myConnect.open();
string myStringCommand = "SELECT ordinal, codeOfStu, fullName, ST.codeOfClass, CL.nameOfClass FROM Student ST, Class CL WHERE ST.codeOfClass = CL.codeOfClass AND ST.codeOfClass = @SelectedCodeOfClass";
OleDbCommand command = new OleDbCommand(myStringCommand, myConnect);
OleDbParameter myParameter = new OleDbParameter("@SelectedCodeOfClass", OleDbType.Integer);
myParameter.Value = SelectedCodeOfClass; // SelectedCodeOfClass is a parameter which is carried from main function.
myCommand.Parameters.Add(myParameter);
OleDbDataReader myReader = myCommand.ExecuteReader();
.
.
.

Now, I want not use "connect model" to access database anymore. I want use "disconnect model" to do that.
If I do like this:
OleDbDataAdapter adap=new OleDbDataAdapter("select * from tablename",con);
Dataset ds=new Dataset();
adap.fill(ds);

The Thing I receive is a datatable involve in all of the students. I don''t want read all of the Student ''s Information in database. I only want read students'' Information according to class (codeOfClass) that they belong to

推荐答案

说您想要的课程代码是103010a
将此行更改为

OleDbDataAdapter adap =新的OleDbDataAdapter(从表名中选择*"，con);

OleDbDataAdapter adap =新的OleDbDataAdapter(从表名中选择*，其中CodeOfClass =``103010a''"，con);

如果它是int类型，则删除''s

Say the Code Of Class you want is 103010a
Change this line to

OleDbDataAdapter adap=new OleDbDataAdapter("select * from tablename",con);

OleDbDataAdapter adap=new OleDbDataAdapter("select * from tablename where CodeOfClass = ''103010a''",con);

if its an int type, remove the ''s

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