sql解析

http://social.msdn.microsoft.com/Forums/en-US/sqlnetfx/thread/fbcb255f-bcb7-45d8-9991-270a329b3d51/

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Microsoft.Data.Schema.ScriptDom;
using Microsoft.Data.Schema.ScriptDom.Sql;
using System.IO;

namespace ConsoleApplication27
{
    class SqlPareCenter
    {
        TSql100Parser parser;

        public SqlPareCenter()
        {
            parser = new TSql100Parser(false);
        }

        public List<FieldInfo> GetSQLFields(string query)
        {
            IList<ParseError> errors;
            IScriptFragment result = parser.Parse(new StringReader(query), out errors);
            List<FieldInfo> list = new List<FieldInfo>();

            TSqlStatement statement = ((TSqlScript)result).Batches[0].Statements[0];

            foreach (var item in (((QuerySpecification)((SelectStatement)statement).QueryExpression).SelectElements))
            {
                SelectColumn c = (SelectColumn)item;

                string alias = c.ColumnName == null ? "" : GetStringFromTSqlFragment(query, c.ColumnName);
                string express = GetStringFromTSqlFragment(query, item);
                list.Add(new FieldInfo() { Alias = alias, Express = express });
                Console.WriteLine(alias + " : " + express);

                //Console.WriteLine(GetStringFromTSqlFragment(query, item) + " Alias: " + (c.ColumnName == null ? "" : GetStringFromTSqlFragment(query, c.ColumnName)));
            }
            return list;

        }

        private string GetStringFromTSqlFragment(string wholeStatementString, TSqlFragment fragment)
        {
            return wholeStatementString.Substring(fragment.StartOffset, fragment.FragmentLength);
        }
    }
}