I am using Linq in C#. I have defined my own function like this
public static void AutoSuggest(TextBox t, string columnName, string tableName)
{
}
In this user defined function, using the parameters, I want to get the specified column data from the specified table of the database.
So, how should I generate this query in Linq?
If you wish to use LINQ, you would be better talking about a source and selector; some IQueryable<T> and something like Expression<Func<T,string>>. If you want to use column/table names, firstly they must be white-listed (don't ever accept the names from, say, a web-request), but the code would be simply:
var values = dataContext.ExecuteQuery<string>("select distinct [" + columnName
+ "] from [" + tableName +"]").ToList();
this is a pretty naive approach, but it shows basic usage; then you would data-bind as normal. However, I'd be much more inclined for the calling code just to do, for example:
var values = dataContext.SomeTable.Select(x => x.SomeProperty)
.Distinct().ToList();
which would avoid risk of injection etc.
