根据条件查询返回DataTable

public DataTable GetDataTable(string tableName, string columnName, string queryCondition)

{

                SqlConnection conn = new SqlConnection(ConnectionString);
                SqlDataAdapter sda = new SqlDataAdapter(@"SELECT * FROM " + tableName + " where " + columnName + "='"+ queryCondition+"'", conn);
                DataTable dt = new DataTable();
                sda.Fill(dt);
                dt.Dispose();

                return dt;

}