1.返回一个字符串 public string getValue(string SqlCommandText) { string returnValue; SqlCommand myCommand=new SqlCommand (SqlCommandText,_DataBaseConnection); try { //如果数据库连接没有打开,先打开数据库连接 this.open (); object _value=new object(); _value=myCommand.ExecuteScalar ();//得到查询结果集中的第一行第一列 _DataBaseConnection.Close(); // _DataBaseConnection=null; returnValue=_value==null?"":_value.ToString(); //returnValue=this.getDataSet(SqlCommandText).Tables[0].Rows[0][0].ToString(); return returnValue; } catch(Exception err) { throw err; } } } 2.返回一个DataSet public DataSet getDataSet(string SqlCommandText) { try {// this.open(); SqlDataAdapter myCommand=new SqlDataAdapter (SqlCommandText,_DataBaseConnection); DataSet ds=new DataSet(); myCommand.Fill(ds,"Table0"); // if(this._DBType==DBType.History) // { _DataBaseConnection.Close(); // // _DataBaseConnection=null; // } return ds; } catch(Exception err) { throw err; } } [C++, JScript] 没有可用于 C++ 或 JScript 的示例。若要查看 Visual Basic 或 C# 示例,请单击页左上角的语言筛选器按钮 。
返回后与datagrid绑定DataView dv=getDataSet(sqlstr).Tables[0].DefaultView;
datagrid1.DataSource=dv;
datagrid1.DataBind();
返回后与datagrid绑定DataView dv=getDataSet(sqlstr).Tables[0].DefaultView;
datagrid1.DataSource=dv;
datagrid1.DataBind();
conn.Open();
System.Data.SqlClient.SqlDataAdapter da = new System.Data.SqlClient.SqlDataAdapter("select * from student",conn);
dt = new System.Data.DataSet();
da.Fill(dt,"student");然后绑定数据集和DataGrid
DataGrid.SetDataBinding(dt,"student");
如果需要,可以绑定TextBox来作录入,而用DataGrid显示
this.textBox16.DataBindings.Add("Text",dt,"student.stuno");
然后进行数据的操作如:
增加:
this.BindingContext[dt,"student"].AddNew();
删除:
this.BindingContext[dt,"student"].RemoveAt(this.BindingContext[dt,"student"].Position);
最后把结果写回数据库:
// sqlInsertCommand1
//
this.sqlInsertCommand1.CommandText = "INSERT INTO student(stuno, name) VALUES (@stuno, @name)";
this.sqlInsertCommand1.Connection = this.conn;
this.sqlInsertCommand1.Parameters.Add(new System.Data.SqlClient.SqlParameter("@stuno", System.Data.SqlDbType.VarChar, 4, "stuno"));
this.sqlInsertCommand1.Parameters.Add(new System.Data.SqlClient.SqlParameter("@name", System.Data.SqlDbType.VarChar, 50, "name"));
//
// sqlUpdateCommand1
//
this.sqlUpdateCommand1.CommandText = "UPDATE student SET stuno = @stuno, name = @name WHERE (stuno = @Original_stuno)";
this.sqlUpdateCommand1.Connection = this.conn;
this.sqlUpdateCommand1.Parameters.Add(new System.Data.SqlClient.SqlParameter("@stuno", System.Data.SqlDbType.VarChar, 4, "stuno"));
this.sqlUpdateCommand1.Parameters.Add(new System.Data.SqlClient.SqlParameter("@name", System.Data.SqlDbType.VarChar, 50, "name"));
this.sqlUpdateCommand1.Parameters.Add(new System.Data.SqlClient.SqlParameter("@Original_stuno", System.Data.SqlDbType.VarChar, 4, System.Data.ParameterDirection.Input, false, ((System.Byte)(0)), ((System.Byte)(0)), "stuno", System.Data.DataRowVersion.Original, null));
// sqlDeleteCommand1
//
this.sqlDeleteCommand1.CommandText = "DELETE FROM student WHERE (stuno = @Original_stuno)";
this.sqlDeleteCommand1.Connection = this.conn;
this.sqlDeleteCommand1.Parameters.Add(new System.Data.SqlClient.SqlParameter("@Original_stuno", System.Data.SqlDbType.VarChar, 4, System.Data.ParameterDirection.Input, false, ((System.Byte)(0)), ((System.Byte)(0)), "stuno", System.Data.DataRowVersion.Original, null));
this.sqlDa.DeleteCommand = this.sqlDeleteCommand1;
this.sqlDa.InsertCommand = this.sqlInsertCommand1;
this.sqlDa.UpdateCommand = this.sqlUpdateCommand1;
try
{
sqlDa.Update(dt.GetChanges,"student");
return true;
}
catch(System.Data.SqlClient.SqlException ex)
{
return false;
}
finally
{
conn.Close();
}
conn.Open();
System.Data.SqlClient.SqlDataAdapter da = new System.Data.SqlClient.SqlDataAdapter("select * from student", conn);
System.Data.SqlClient.SqlCommandBuilder MyCB = new System.Data.SqlClient.SqlCommandBuilder(da);
da.MissingSchemaAction = MissingSchemaAction.AddWithKey;
da.Update(dt, "HR_EMPIMAGE");
SqlDataAdapter catDA = new SqlDataAdapter("SELECT CategoryID, CategoryName FROM Categories", nwindConn); catDA.UpdateCommand = new SqlCommand("UPDATE Categories SET CategoryName = @CategoryName " +
"WHERE CategoryID = @CategoryID" , nwindConn);catDA.UpdateCommand.Parameters.Add("@CategoryName", SqlDbType.NVarChar, 15, "CategoryName");SqlParameter workParm = catDA.UpdateCommand.Parameters.Add("@CategoryID", SqlDbType.Int);
workParm.SourceColumn = "CategoryID";
workParm.SourceVersion = DataRowVersion.Original;DataSet catDS = new DataSet();
catDA.Fill(catDS, "Categories"); DataRow cRow = catDS.Tables["Categories"].Rows[0];
cRow["CategoryName"] = "New Category";catDA.Update(catDS);