CODEWITHSUNDEEP
c#mysqllivecharts
Ezio Farenze
Ezio Farenze

Reputation: 89

Unable to cast object of type 'System.DateTime' to type 'System.String'. c#

I'm trying to display the dates and restored it to the Labels = strings, but I got an error on line list.Add((string)myReader["Date"]);

Here's my code:

con.Open();
myReader = cmdDB.ExecuteReader();
List<string> list = new List<string>();
while (myReader.Read())
{
    list.Add((string)myReader["Date"]);
}

string[] strings = list.Select(x => x.ToString()).ToArray();
cartesianChart1.AxisX.Add(new Axis
{
    Title = "Date",
    Labels = strings
});

cartesianChart1.AxisY.Add(new Axis
{
    Title = "Sales",
    LabelFormatter = value => value.ToString()
});

Any solution? Thank you! P.S. I'm using LiveCharts and MySQL.

Upvotes: 2

Views: 41995

Answers (4)

Muhammad Abdullah
Muhammad Abdullah

Reputation: 4465

Note: if we have column of type DateTime in DataBase and String in asp.net core/Csharp application

we can convert DateTime to string at store procedure level as

e.g

    date_format(ReferralDate, '%d/%m/%Y') as ReferralDate,

Full example of Store procedure

SELECT  referralCostsID,
        ClientID,
        ReferralSource,
        date_format(ReferralDate, '%d/%m/%Y') as ReferralDate,
        AdCost,
        Notes

FROM referralcostssetup

Upvotes: 0

Harlin Acero
Harlin Acero

Reputation: 87

Use

 if (Convert.IsDBNull(columnValue))
 {
      return null;
 }
  return columnValue;

Ever validate is data is null or emty and return a value

Upvotes: -1

Nikhil Agrawal
Nikhil Agrawal

Reputation: 48558

Do 

list.Add(Convert.ToString(myReader["Date"]));

It seems your Datecolumn is not string but a datetime column.

Doing (string)myReader["Date"] tries explicit typecasting on a datetime column to string which is not possible. But Convert.ToString gives the string representation of your value.

Even if the value is null, Convert.ToString(object value) will return null instead of throwing exception like .ToString().

Upvotes: 2

Mohit S
Mohit S

Reputation: 14024

You can try like this

list.Add(myReader["Date"].ToString());

If you want you can also apply formatting to your date in the ToString(dd-MM-yyyy) using Custom Date and Time Format Strings

Upvotes: 9

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