Question

I execute a string query using EF 4:

string query = "SELECT * FROM Table WHERE ....";

  [+ build WHERE clausule based on the user's input values]

 db.ExecuteStoreQuery<TAble>(query).ToList();

I’m wondering how to prevent that query from SQL Injection in taht WHERE clausule. Any ideas ?

Answer 1

You need to use a parameterized query:

// Build where clause
var filters = new StringBuilder();
var parameters = new List<object>();
if (!string.IsNullOrEmpty(name))
{
    if (filters.Length > 0)
        filters.Append(" AND ");
    filters.Append("name = @name");
    var param = new SqlParameter("@name", SqlDbType.NVarChar);
    param.Value = name;
    parameters.Add(param);
}
...


// Build query
string query = "SELECT * FROM Table";
if (filters.Length > 0)
    query = query + " WHERE " + filters;

// Execute
db.ExecuteStoreQuery<TAble>(query, parameters.ToArray()).ToList();