Question

我有一个组合框来设置@NULLFather' and '@NULLMother的值。勾选组合框时，存储过程的WHERE子句检查@NULLFather' and '@NULLMother的值，并根据该值给出结果。但我无法让它发挥作用。这是代码。我也试过了这个案例，但仍然没有成功。

USE myStudentDB
GO

SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO

ALTER PROCEDURE [dbo].[ManualSearchStudents]
-- Add the parameters for the stored procedure here

@NullFather int = 1,
@NullMother int = 1

AS
BEGIN
 SET NOCOUNT ON;

 -- Insert statements for procedure here

 SELECT StudentName, FatherName, MotherName
 FROM StudentTable 
 WHERE  IF(NULLFather > 0) THEN FatherName IS NULL 
  AND   IF(NullMother > 0) THEN MotherName IS NULL 
 ORDER BY StudentTable.StudentID DESC 
END

Answer 1

我实施了不同的解决方案：

首先调用存储过程并将其保存到dataTable。从组合框生成sql语句字符串。将新的sql字符串应用于dataTable。问题解决了。应用这个，效果很好。这是代码：

    private DataTable StudentDataExtract()
   {          
         DataTable ds = new DataTable();

        try
        {


            string sqlSelect = "SearchStudents";
            EntityConnection scontext = new EntityConnection();
            SqlConnection c = new SqlConnection(scontext.Database.Connection.ConnectionString);
            SqlCommand cmd = new SqlCommand(sqlSelect, c); //c.con is the connection string
            cmd.CommandType = CommandType.StoredProcedure;

            c.Open();


            SqlDataAdapter da = new SqlDataAdapter(cmd);
            SqlCommandBuilder commandBuilder = new SqlCommandBuilder(da);

            da.Fill(ds);

            c.Close();

            if (GetFilter != "")
            {
                ds = ManualFilter(ds);
            }
            else
            {
                string dataOrder = "SID DESC";
                DataView dv = ds.DefaultView;
                dv.Sort = dataOrder;
                ds = dv.ToTable();
            }

            return ds;

        }
        catch (SqlException e)

        {
            return ds;
        }
    }


    private DataTable ManualFilter(DataTable OldDataTable)
    {
        DataTable NewDataTable = new DataTable();
        try
        {
            NewDataTable = OldDataTable.Select(GetFilter, dataOrder).CopyToDataTable();
            return NewDataTable;
        }
        catch (SqlException)
        {
            return NewDataTable;
        }
        catch(Exception)
        {
            return NewDataTable;
        }
    }

    private string getfilter = "";
    public string GetFilter
    {
        get
        {
            IEnumerable<String> selectedData = combolist.Where(d => d.IsSelected).Select(d => d.myTableValue);
            string singleString = string.Join(" OR ", selectedData.ToArray());
            return singleString;
        }
        set
        {
            getfilter = value; OnPropertyChanged("GetFilter"); OnPropertyChanged("GetStudentData");
        }

    }




    public DataTable GetStudentData
    {
        get
        {
            return this.StudentDataExtract();
        }

    }


   public class ComboSet : ViewModelBase
    {
        private bool isSelected;
        public bool IsSelected
        {
            get { return isSelected; }
            set { isSelected = value; OnPropertyChanged("IsSelected"); OnPropertyChanged("GetFilter"); }
        }

        private string mydataproperty;

        public string myDataProperty
        {
            get { return mydataproperty; }
            set { mydataproperty = value; }
        }

        private string mytablevalue;

        public string myTableValue
        {
            get { return mytablevalue; }
            set { mytablevalue = value; }
        }

    }

    private ObservableCollection<ComboSet> combolist;

    public ObservableCollection<ComboSet> ComboList
    {
        get { return combolist; }
        set { combolist = value; }
    }

具有条件Where子句

1 个答案: