where条件的lambda转化为sql语句

网上找的源码，但是博主说有bug 让自己调试。这个是我经过多次修改后的代码，可以直接用
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public static class LambdaToSqlHelper
   {
       
 
       #region 基础方法
 
       #region 获取条件语句方法
 
       private static string GetWhereSql<T>(Expression<Func<T, bool>> func, List<ParMODEL> parModelList) where T : class
       {
           string res = "";
           if (func.Body is BinaryExpression)
           {
               //起始参数
 
               BinaryExpression be = ((BinaryExpression)func.Body);
               res = BinarExpressionProvider(be.Left, be.Right, be.NodeType, parModelList);
           }
           else if (func.Body is MethodCallExpression)
           {
               MethodCallExpression be = ((MethodCallExpression)func.Body);
               res = ExpressionRouter(func.Body, parModelList);
           }
           else
           {
               res = "  ";
           }
 
           return res;
       }
 
       #endregion 获取条件语句方法
 
 
 
       #region 获取排序语句 order by
 
       private static string GetOrderSql<T>(Expression<Func<T, object>> exp) where T : class
       {
           var res = "";
           if (exp.Body is UnaryExpression)
           {
               UnaryExpression ue = ((UnaryExpression)exp.Body);
               List<ParMODEL> parModelList = new List<ParMODEL>();
               res = "order by `" + ExpressionRouter(ue.Operand, parModelList).ToLower() + "`";
           }
           else
           {
               MemberExpression order = ((MemberExpression)exp.Body);
               res = "order by `" + order.Member.Name.ToLower() + "`";
           }
           return res;
       }
 
       #endregion 获取排序语句 order by
 
      
 
       #endregion 基础方法
 
       #region 底层
 
       public static bool In<T>(this T obj, T[] array)
       {
           return true;
       }
 
       public static bool NotIn<T>(this T obj, T[] array)
       {
           return true;
       }
 
       public static bool Like(this string str, string likeStr)
       {
           return true;
       }
 
       public static bool NotLike(this string str, string likeStr)
       {
           return true;
       }
 
       private static string GetValueStringByType(object oj)
       {
           if (oj == null)
           {
               return "null";
           }
           else if (oj is ValueType)
           {
               return oj.ToString();
           }
           else if (oj is string || oj is DateTime || oj is char)
           {
               return string.Format("'{0}'", oj.ToString());
           }
           else
           {
               return string.Format("'{0}'", oj.ToString());
           }
       }
 
       private static string BinarExpressionProvider(Expression left, Expression right, ExpressionType type, List<ParMODEL> parModelList)
       {
           string sb = "(";
           //先处理左边
           string reLeftStr = ExpressionRouter(left, parModelList);
           sb += reLeftStr;
 
           sb += ExpressionTypeCast(type);
 
           //再处理右边
           string tmpStr = ExpressionRouter(right, parModelList);
           if (tmpStr == "null")
           {
               if (sb.EndsWith(" ="))
               {
                   sb = sb.Substring(0, sb.Length - 2) + " is null";
               }
               else if (sb.EndsWith("<>"))
               {
                   sb = sb.Substring(0, sb.Length - 2) + " is not null";
               }
           }
           else
           {
               //添加参数
               sb += tmpStr;
           }
 
           return sb += ")";
       }
 
       private static string ExpressionRouter(Expression exp, List<ParMODEL> parModelList)
       {
           string sb = string.Empty;
 
           if (exp is BinaryExpression)
           {
               BinaryExpression be = ((BinaryExpression)exp);
               return BinarExpressionProvider(be.Left, be.Right, be.NodeType, parModelList);
           }
           else if (exp is MemberExpression)
           {
               MemberExpression me = ((MemberExpression)exp);
               if (!exp.ToString().StartsWith("value"))
               {
                   return me.Member.Name;
               }
               else
               {
                   var result = Expression.Lambda(exp).Compile().DynamicInvoke();
                   if (result == null)
                   {
                       return "null";
                   }
                   else if (result is ValueType)
                   {
                       ParMODEL p = new ParMODEL();
                       p.name = "par" + (parModelList.Count + 1);
                       p.value = result.ToString().ToIntByStr();
                       parModelList.Add(p);
                       //return ce.Value.ToString();
                       return "@par" + parModelList.Count;
                   }
                   else if (result is string || result is DateTime || result is char)
                   {
                       ParMODEL p = new ParMODEL();
                       p.name = "par" + (parModelList.Count + 1);
                       p.value = result.ToString();
                       parModelList.Add(p);
                       //return string.Format("'{0}'", ce.Value.ToString());
                       return "@par" + parModelList.Count;
                   }
                   else if (result is int[])
                   {
                       var rl = result as int[];
                       StringBuilder sbIntStr = new StringBuilder();
                       foreach (var r in rl)
                       {
                           ParMODEL p = new ParMODEL();
                           p.name = "par" + (parModelList.Count + 1);
                           p.value = r.ToString().ToIntByStr();
                           parModelList.Add(p);
                           //return string.Format("'{0}'", ce.Value.ToString());
                           sbIntStr.Append("@par" + parModelList.Count + ",");
                       }
                       return sbIntStr.ToString().Substring(0, sbIntStr.ToString().Length - 1);
                   }
                   else if (result is string[])
                   {
                       var rl = result as string[];
                       StringBuilder sbIntStr = new StringBuilder();
                       foreach (var r in rl)
                       {
                           ParMODEL p = new ParMODEL();
                           p.name = "par" + (parModelList.Count + 1);
                           p.value = r.ToString();
                           parModelList.Add(p);
                           //return string.Format("'{0}'", ce.Value.ToString());
                           sbIntStr.Append("@par" + parModelList.Count + ",");
                       }
                       return sbIntStr.ToString().Substring(0, sbIntStr.ToString().Length - 1);
                   }
               }
           }
           else if (exp is NewArrayExpression)
           {
               NewArrayExpression ae = ((NewArrayExpression)exp);
               StringBuilder tmpstr = new StringBuilder();
               foreach (Expression ex in ae.Expressions)
               {
                   tmpstr.Append(ExpressionRouter(ex, parModelList));
                   tmpstr.Append(",");
               }
               //添加参数
 
               return tmpstr.ToString(0, tmpstr.Length - 1);
           }
           else if (exp is MethodCallExpression)
           {
               MethodCallExpression mce = (MethodCallExpression)exp;
               string par = ExpressionRouter(mce.Arguments[0], parModelList);
               if (mce.Method.Name == "Like")
               {
                   //添加参数用
                   return string.Format("({0} like {1})", par, ExpressionRouter(mce.Arguments[1], parModelList));
               }
               else if (mce.Method.Name == "NotLike")
               {
                   //添加参数用
                   return string.Format("({0} Not like {1})", par, ExpressionRouter(mce.Arguments[1], parModelList));
               }
               else if (mce.Method.Name == "In")
               {
                   //添加参数用
                   return string.Format("{0} In ({1})", par, ExpressionRouter(mce.Arguments[1], parModelList));
               }
               else if (mce.Method.Name == "NotIn")
               {
                   //添加参数用
                   return string.Format("{0} Not In ({1})", par, ExpressionRouter(mce.Arguments[1], parModelList));
               }
           }
           else if (exp is ConstantExpression)
           {
               ConstantExpression ce = ((ConstantExpression)exp);
               if (ce.Value == null)
               {
                   return "null";
               }
               else if (ce.Value is ValueType)
               {
                   ParMODEL p = new ParMODEL();
                   p.name = "par" + (parModelList.Count + 1);
                   p.value = ce.Value.ToString().ToIntByStr();
                   parModelList.Add(p);
                   //return ce.Value.ToString();
                   return "@par" + parModelList.Count;
               }
               else if (ce.Value is string || ce.Value is DateTime || ce.Value is char)
               {
                   ParMODEL p = new ParMODEL();
                   p.name = "par" + (parModelList.Count + 1);
                   p.value = ce.Value.ToString();
                   parModelList.Add(p);
                   //return string.Format("'{0}'", ce.Value.ToString());
                   return "@par" + parModelList.Count;
               }
 
               //对数值进行参数附加
           }
           else if (exp is UnaryExpression)
           {
               UnaryExpression ue = ((UnaryExpression)exp);
 
               return ExpressionRouter(ue.Operand, parModelList);
           }
           return null;
       }
 
       private static string ExpressionTypeCast(ExpressionType type)
       {
           switch (type)
           {
               case ExpressionType.And:
               case ExpressionType.AndAlso:
                   return " AND ";
 
               case ExpressionType.Equal:
                   return " =";
 
               case ExpressionType.GreaterThan:
                   return " >";
 
               case ExpressionType.GreaterThanOrEqual:
                   return ">=";
 
               case ExpressionType.LessThan:
                   return "<";
 
               case ExpressionType.LessThanOrEqual:
                   return "<=";
 
               case ExpressionType.NotEqual:
                   return "<>";
 
               case ExpressionType.Or:
               case ExpressionType.OrElse:
                   return " Or ";
 
               case ExpressionType.Add:
               case ExpressionType.AddChecked:
                   return "+";
 
               case ExpressionType.Subtract:
               case ExpressionType.SubtractChecked:
                   return "-";
 
               case ExpressionType.Divide:
                   return "/";
 
               case ExpressionType.Multiply:
               case ExpressionType.MultiplyChecked:
                   return "*";
 
               default:
                   return null;
           }
       }
 
       #endregion 底层
   }
 
 
 
   public class SqlParMODEL
   {
       public string sql { set; get; }
 
       private List<ParMODEL> parList { set; get; }
   }
 
   public class ParMODEL
   {
       public string name { set; get; }
 
       public object value { set; get; }
   }