CODEWITHSUNDEEP
c#datetimedataset
TTT
TTT

Reputation: 1885

C# DataSet: How can I know if a column is a of DateTime/Boolean type

In C#, I create some dataset or datatable from some query.

Data which comes from DateTime columns in the database are typed as System.String.

Is there a way to know programatically identify a column as containing a DateTime information ?

Sames question for boolean data which is considered as System.Int32 ?

Thank you

EDIT1 because it seems that this wasn't totally understood:

MyDataColumn.DataType is "System.String" (for DateTime) !

MyDataColumn.DataType is "System.Int32" (for Boolean) !

So I can't get the in I want from DataType, otherwise I wouldn't even have posted this.

EDIT2 And the TryParse() idea has a big problem here, it's more obvious with the Boolean/System.Int32 confusion: If I see "1" or "0" I could think that it's a Boolean while it may as well be an Int32 column. TryParse() has the same flaw.

Upvotes: 3

Views: 6543

Answers (4)

Hossein Narimani Rad
Hossein Narimani Rad

Reputation: 32481

EDIT:

To check the containing data you may try to parse its values. so for each value in that column you do like this:

 DateTime dateTime;
 DateTime.TryParse("your string", out dateTime);

Upvotes: 3

Habib
Habib

Reputation: 223247

You can use LINQ to see if any column of DateTime type exists in your datatable. You need to parse each column with DateTime.TryParse to see if any column gets successfully parsed like:

 if (dt == null || dt.Rows.Count <= 0)
    return false;

DateTime temp;
if (dt.Rows[0].ItemArray.Any(r => DateTime.TryParse(r.ToString(), 
                                CultureInfo.InvariantCulture,
                                DateTimeStyles.None, 
                                out temp)))

{
 //Column exists.

}

If you want to get the column index then you can try:

var column = dt.Rows[0].ItemArray
                           .Select((r, index) => new { Value = r, Index = index })
                           .FirstOrDefault(t => DateTime.TryParse(t.ToString(),
                                                CultureInfo.InvariantCulture,
                                                DateTimeStyles.None,
                                                out temp));
if(column != null)
    Console.WriteLine(column.Index);

(Remember to include System.LINQ)

Upvotes: 0

Ram Singh
Ram Singh

Reputation: 6918

Create a stored proc like the follow:

Alter proc proc_GetDataTypeValueByColumnName
(    
@TableName varchar(500)='tblAdminUser',    
@ColumnName varchar(500)='Id'    
)    
as    
declare @DataType varchar(500);    
if exists(select 1 from sys.tables where name=@TableName)    
begin    
  set @DataType=(SELECT t.Name 'Data type'FROM sys.columns c INNER JOIN     
   sys.types t ON c.system_type_id = t.system_type_id    
  WHERE    
   c.object_id = OBJECT_ID(''+@TableName+'') and c.name=@ColumnName)    
-- select dbo.GetDataTypeValue(@DataType)  
select   @DataType
End

You need to pass the table name and the column name of which you want to get the datatype if you want to get it in the code then you can go for the following stuff:

public String GetNumberForDataTypeofColumn(String TableName, String ColumnName)
{
    SqlParameter[] param = new SqlParameter[2];
    param[0] = new SqlParameter("@TableName", TableName);
    param[1] = new SqlParameter("@ColumnName", ColumnName);
    String result = SqlHelper.ExecuteScalar(ConfigurationManager.ConnectionStrings["cn"].ConnectionString, CommandType.StoredProcedure, "proc_GetDataTypeValueByColumnName", param).ToString();
    return result;
}

And there is another way that is :: data Column has property "DataType" you can also check from that like below:

dtItems.Columns[0].DataType

Hope this will help you

Upvotes: 1

skyfree
skyfree

Reputation: 906

if (myDataTable.Columns["thisColumn"].DataType == System.Type.GetType("System.DateTime"))
{
...
}
else
{
}

Upvotes: 4

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