CODEWITHSUNDEEP
c#loopsforeachdatatable
CryoFusion87
CryoFusion87

Reputation: 796

C# replace values in a Datatable

I need to replace integers values inside a datatable with a string symbol (*) if they are greater than 0 and less than 5.

So far I can loop through each row and the corresponding columns but I am unable to get the individual values contained in the datatable.

The code I have written so far is shown below:

public static DataTable SupressDataTable(DataTable cases)
    {
        DataTable suppressedDataTable = new DataTable();

        foreach (var row in cases.Rows)
        {
            foreach (DataColumn column in cases.Columns)
            {
                if (column.IsNumeric())
                {
                }
            }
        }

        return suppressedDataTable;
    }

    public static bool IsNumeric(this DataColumn col)
    {
        if (col == null)
            return false;
        // Make this const
        var numericTypes = new[] { typeof(Byte), typeof(Decimal), typeof(Double),
            typeof(Int16), typeof(Int32), typeof(Int64), typeof(SByte),
            typeof(Single), typeof(UInt16), typeof(UInt32), typeof(UInt64)};
        return ((IList) numericTypes).Contains(col.DataType);
    }

How do I get to the values and then replace them?

Upvotes: 1

Views: 1339

Answers (1)

Tim Schmelter
Tim Schmelter

Reputation: 460288

You can't do that with the original table because an int or double column is not a string column. You need a new table where each numeric column is replaced with a string column:

public static DataTable SupressDataTable(DataTable cases)
{
    DataTable suppressedDataTable = cases.Copy(); // Same columns, same data
    DataColumn[] allNumericColumns = suppressedDataTable.Columns.Cast<DataColumn>().Where(IsNumeric).ToArray();
    foreach (DataColumn numericCol in allNumericColumns)
    {
        int ordinal = numericCol.Ordinal; // need to store before remove
        suppressedDataTable.Columns.Remove(numericCol);
        suppressedDataTable.Columns.Add(numericCol.ColumnName); // string column
        suppressedDataTable.Columns[numericCol.ColumnName].SetOrdinal(ordinal);
    }

    for (int index = 0; index < suppressedDataTable.Rows.Count; index++)
    {
        DataRow row = suppressedDataTable.Rows[index];
        foreach (DataColumn column in cases.Columns)
        {
            if (IsNumeric(column))
            {
                dynamic numVal = cases.Rows[index][column];
                string newValue = numVal > 0 && numVal < 5 ? "*" : numVal.ToString();
                row.SetField(column.Ordinal, newValue);
            }
        }
    }

    return suppressedDataTable;
}

Upvotes: 1

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