如何从C＃在SQL存储过程中传递日期值

Question

I need to insert purchase date in table.

My table

purchaseDate date (data type)

C# code

string purchaseDate = "";
public string _PurchaseDate
{
    get { return purchaseDate; }
    set
    {
        DateTime purchaseDateF = DateTime.Parse(value.Trim());
        purchaseDate = purchaseDateF.ToString("dd-MM-yy");
    }
}

My stored Proc

@purchasedate,

insert into tbl_name (purchaseDate) values (@purchasedate)

If I pass purchaseDate = "29-may-14" its showing error on converting nvarchar into date.

Where did I make an error?

Thanks...

Answer 1

Don't pass it as a string. Pass it as a date/time . In fact, it is very unclear to me why _PurchaseDate is a string and not a DateTime in the first place. But however it is stored in your app: when you add it as a parameter, convert (parse) it to a DateTime first , and add the typed date. Not a string .

In an ideal world:

public DateTime PurchaseDate {get;set;}
//...
cmd.Parameters.AddWithValue("purchasedate", obj.PurchaseDate);

Then nothing more is required.

Answer 2

Instead of inserting it in a certain format, insert as normal DateTime value and then when retreieving it, convert to formatted string...

Change your C# datatype from string to date:

    public DateTime _PurchaseDate{get;set;}

Do your insert with "_PurchaseDate", I am guessing you want to display it on a client app in a certain format, so then add property like this:

    public string _StrPurchaseDate
    {
        get
        {
            return ((DateTime)_PurchaseDate).ToString("dd-MM-yyyy");
        }
        set
        {

        }
    }

now just retrieve the date as a string, unless you really need to store it as a certain format in sql

NOTE: If your database Date column contains NULLS, it will break when retrieving values from the database so change to nullable DateTime datatype and then check for nulls when converting:

    public DateTime? _PurchaseDate{get;set;}

    public string _StrPurchaseDate
    {
        get
        {
            if (_PurchaseDate != null)
            {
                return ((DateTime)_PurchaseDate).ToString("dd-MM-yyyy");
            }
            else
            {
                return "";
            }
        }
        set
        {

        }
    }

Answer 3

在存储过程中使用CAST或CONVERT可以将string值转换为适当的数据库类型。