C#中一套生成sql条件的类

    在进行sql查询的时候，有时候要进行很多条件限制，自己来拼写SQLwhere条件容易出错，而且判断条件复杂，后期维护困难，基于这个原因我在一个小 项目中写了一套生成sql条件的类。总共包括一个Condition类，与两个枚举型类型（LogicOper，CompareOper）
代码如下：

    public class Condition
    ...{
        static string [] logicOpers = new string[]...{"and","or"};
        static string [] compareOpers = new string[]...{">","<","<=",">=","=","<>","like","not like","in"};

        string compareOper=null;
        string name=null;
        string templateName = null;
        string valType=null;
        object val=null;
        public Condition(CompareOper co,string valType,string name,object val)
        ...{
            this.compareOper = compareOpers[(int)co];
            this.name = name;
            templateName = name;
            this.valType = valType;
            this.val = val;
        }
        public Condition(CompareOper co,string valType,string name,object val,string templateName)
        ...{
            this.compareOper = compareOpers[(int)co];
            this.name = name;
            this.templateName = templateName;
            this.valType = valType;
            this.val = val;
        }
        public Condition()...{}

        public string toSqlString() [Page]
        ...{
            string []  arr1 =  (string[])operaters.ToArray("".GetType());
            Condition []  arr2 =  (Condition[])conditions.ToArray((new Condition()).GetType());
            
            StringBuilder outStr = new StringBuilder();

            int count=0;
            if(name!=null&&val!=null)
            ...{
                outStr.Append(name);
                outStr.Append(" ");
                outStr.Append(compareOper);
                outStr.Append(" ");
                if(valType.ToLower()=="int"
                    ||valType.ToLower()=="float"
                    ||valType.ToLower()=="double"
                    ||valType.ToLower()=="bool"
                    ||valType.ToLower()=="number"

     )
                ...{
                    outStr.Append(val);
                } [Page]
                else if(valType.ToLower()=="string")
                ...{
                    string tmp = (string)val;
                    outStr.Append("’"+tmp.Replace("’","’’")+"’");
                }
                else if(valType.ToLower()=="date")
                ...{
                    DateTime dt = (DateTime)val;
                    outStr.Append("’"+dt.ToString("yyyy-MM-dd")+"’");
                }
                else if(valType.ToLower()=="datetime")
                ...{
                    DateTime dt = (DateTime)val;
                    outStr.Append("’"+dt.ToString("yyyy-MM-dd hh:mm:ss.fff")+"’");
                }
                else
                ...{
                    string tmp = val.ToString();
                    outStr.Append("’"+tmp.Replace("’","’’")+"’"); [Page]
                }
                count++;
            } 
            if(arr1.Length>0)
            ...{
                for(int i=0;i<arr1.Length;i++)
                ...{
                    if(arr2[i].toSqlTempletString()=="")
                        continue;
                    count++;
                    if((name!=null&&val!=null)||count>1)
                    ...{
                        outStr.Append(" ");
                        outStr.Append(arr1[i]);
                        outStr.Append(" ");


                    }
                    outStr.Append(arr2[i].toSqlString());
                }
            }
            if(count>1)
            ...{ [Page]
                outStr.Insert(0,’(’);
                outStr.Append(’)’);
            }
            return outStr.ToString();
        }

        public string toSqlTempletString()
        ...{
            string []  arr1 =  (string[])operaters.ToArray("".GetType());
            Condition []  arr2 =  (Condition[])conditions.ToArray((new Condition()).GetType());
            
            StringBuilder outStr = new StringBuilder();

            int count=0;
            if(name!=null&&val!=null)
            ...{
                outStr.Append(name);
                outStr.Append(" ");
                outStr.Append(compareOper);
                outStr.Append(" @");
                outStr.Append(templateName);
                count++;
            }

            if(arr1.Length>0)
            ...{
                for(int i=0;i<arr1.Length;i++) [Page]
                ...{
                    if(arr2[i].toSqlTempletString()=="")
                        continue;
                    count++;
                    if((name!=null&&val!=null)||count>1)
                    ...{
                        outStr.Append(" ");
                        outStr.Append(arr1[i]);
                        outStr.Append(" ");
                    }
                    outStr.Append(arr2[i].toSqlTempletString());
                }
            } 
             if(count>1)
            ...{
                outStr.Insert(0,’(’);
                outStr.Append(’)’);
            }
            return outStr.ToString();
        }

        public SqlParameter [] getSqlParameters() [Page]
        ...{
            ArrayList tmp = new ArrayList();
            if(name!=null&&val!=null)
            ...{
                tmp.Add(new SqlParameter("@"+templateName,val));
            }
            Condition []  arr =  (Condition[])conditions.ToArray((new Condition()).GetType());

            for(int i=0;i<arr.Length;i++)
            ...{
                 SqlParameter [] sps = arr[i].getSqlParameters();
                for(int j=0;j<sps.Length;j++)
                ...{
                        tmp.Add(sps[j]);
                }
            }
            return (SqlParameter [])tmp.ToArray(new SqlParameter("","").GetType());
        }
    
        ArrayList operaters  = new ArrayList();
        ArrayList conditions = new ArrayList();

        public void addCondition(LogicOper lo,Condition c)
        ...{
            operaters.Add(logicOpers[(int)lo]);
            conditions.Add(c); [Page]
        }

    }
    
    public enum LogicOper: int
    ...{
        and=0,or=1
    }
    public enum CompareOper: int
    ...{
        moreThan=0,lessThan=1,notMoreThan=2,notLessThan=3,equal=4,notEqual=5,like=6,notLike=7,IN=8
    }


/**//*----------------------------------------------------------------------------------------------------------------------------
使用如下:
            Condition condition =  new Condition(CompareOper.equal,"string","name","%kkp%");
            Condition condition2 =  new Condition(CompareOper.equal,"int","id",1024);
            Condition condition3 =  new Condition(CompareOper.like,"string","nickName","%’kkp’%");
            Condition condition4 =  new Condition(CompareOper.equal,"date","age",DateTime.Now);
            Condition condition5 =  new Condition(CompareOper.equal,"datetime","signTime",DateTime.Now);
            Condition condition6 = new Condition();

 condition.addCondition(LogicOper.or,condition2);
            condition.addCondition(LogicOper.or,condition3);

            condition6.addCondition(LogicOper.or,condition4);
            condition6.addCondition(LogicOper.or,condition5);

            condition6.addCondition(LogicOper.and,condition);

            condition6.toSqlString();
            condition6.toSqlTempletString(); [Page]
            condition6.getSqlParameters(); 

通过Condition类的addCondition方法可以实现任意复杂的条件组合。toSqlString()方法返回sql条件，可以用于sql拼 接方式使用。而toSqlTempletString()方式生成的是以参数形式的 sql条件，配合getSqlParameters()方法可以实现 以参数传递的条件（相当于java中的prepareStatement实现）。

            condition6.toSqlString();
            condition6.toSqlTempletString();
的结果分别是：
(age = ’2007-07-16’ or signTime = ’2007-07-16 02:06:02.667’ and (name = ’%kkp%’ or id = 1024 or nickName like ’%’’kkp’’%’))

(age = @age or signTime = @signTime and (name = @name or id = @id or nickName like @nickName))