You are going to have to loop though the columns to compare. This compare ent.Equals(orgEnt) in your code is comparing if the object references are the same. This doesn't seem like what you want and you want to compare values.
public bool IsChanged(DataTable original, DataTable source, string idKeyName, params string[] ignoreColumns)
{
// make sure "key" column exist in both
if (!original.Columns.Contains(idKeyName) || !source.Columns.Contains(idKeyName))
{
throw new MissingPrimaryKeyException("Primary key column not found.");
}
// if source rows are not the same as original then something was deleted or added
if (source.Rows.Count != original.Rows.Count)
{
return false;
}
// Get a list of columns ignoring passed in and key (key will have to be equal to find)
var originalColumns =
original.Columns.Cast<DataColumn>()
.Select(c => c.ColumnName)
.Where(n => !ignoreColumns.Contains(n) && n != idKeyName)
.ToArray();
// check to make sure same column count otherwise just fail no need to check
var sourceColumnsCount =
source.Columns.Cast<DataColumn>()
.Select(c => c.ColumnName).Count(originalColumns.Contains);
if (originalColumns.Length != sourceColumnsCount)
{
return false;
}
//Switch to linq
var sourceRows = source.AsEnumerable();
return sourceRows.All(sourceRow =>
{
// use select since not real key
var originalCheck = original.Select(idKeyName + " = " + sourceRow[idKeyName]);
if (originalCheck.Length != 1)
{
// Couldn't find key or multiple matches
return false;
}
var originalRow = originalCheck.First();
//Since using same array we can use linq's SequenceEqual to compare for us
return
originalColumns.Select(oc => sourceRow[oc])
.SequenceEqual(originalColumns.Select(oc => originalRow[oc]));
});
}
There might be some micro optimizations but I think no matter what you will have to check each column.