关于SQL语句的自动生成！（五）

作者：PeterXu 来源：Blog.CSDN Blog: http://blog.csdn.net/peterreg/
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接我的上一篇文章《关于SQL语句的自动生成！（四）》，虽然在DotNet Framework3.5 面世以后，可通过LINQ支持SQL的直接查询，但LINQ只支持SQL系列的，SQL2K,SQL2K5，对于ACCESS,ORACLE,MYSQL等不支持。同时平常的一些工具的创作，对于我们的软件水平也大有好处

下面附上DBACCESS的整套代码，供大家分享


public interface IClause




...{


void Add(string name, object val);


void AddWhere(string name, object val);


void Clear();




string TableName ...{ set;}


}




public abstract class ClauseFactory




...{


public enum Flag




...{


Insert,


Update,


Select,


Delete,


}






Create#region Create




public static IClause Create(string table, Flag category)




...{


BaseClause ret = null;


switch (category)




...{


case Flag.Insert:


ret = new Insert();


break;




case Flag.Update:


ret = new Update();


break;




case Flag.Select:


ret = new Select();


break;




case Flag.Delete:


ret = new Delete();


break;




default:


break;


}


if (ret != null)




...{


ret.TableName = table;


}


return ret;


}




#endregion






BaseClause#region BaseClause




private abstract class BaseClause : IClause




...{


private string m_strTable = string.Empty;


private Where m_oWhere = new Where();




protected BaseClause()




...{


this.m_strTable = string.Empty;


this.Clear();


}




public virtual void Add(string name, object val)




...{


}




public void AddWhere(string name, object val)




...{


this.m_oWhere.Add(name, val);


}




public void Clear()




...{


this.m_oWhere.Clear();


this.auxClear();


}




public string TableName




...{




set ...{ this.m_strTable = value; }




protected get ...{ return this.m_strTable; }


}




public sealed override string ToString()




...{


return this.ToStr + this.m_oWhere.ToString();


}






protected abstract string ToStr ...{ get;}




protected virtual void auxClear() ...{ }


}




#endregion






Insert, Update..Join#region Insert, Update..Join




private class Insert : BaseClause




...{


private string m_strName;


private string m_strValue;




public override void Add(string name, object val)




...{


if (val == null)




...{


this.Add(name, "null", false);


}


else




...{


this.Add(name, val.ToString(), val is string || val is DateTime);


}


}




private void Add(string name, string val, bool isref)




...{


if (isref)




...{


val = "'" + val + "'";


}


if (this.m_strName == string.Empty)




...{


this.m_strName = "[" + name + "]";


this.m_strValue = val;


}


else




...{


this.m_strName += ",[" + name + "]";


this.m_strValue += "," + val;


}


}




protected override string ToStr




...{




get ...{ return "INSERT INTO [" + base.TableName + "] ( " + this.m_strName + " ) values ( " + this.m_strValue + " )"; }


}




protected override void auxClear()




...{


this.m_strValue = string.Empty;


this.m_strName = string.Empty;


}


}




private class Delete : BaseClause




...{


public Delete()




...{


}




protected override string ToStr




...{




get ...{ return "DELETE FROM [" + base.TableName + "]"; }


}


}




private class Update : BaseClause




...{


private string m_strUpdate;




public override void Add(string name, object val)




...{


if (val == null)




...{


this.Add(name, "null", false);


}


else




...{


this.Add(name, val.ToString(), val is string || val is DateTime);


}


}




private void Add(string name, string val, bool isref)




...{


if (isref)




...{


val = "'" + val + "'";


}


if (this.m_strUpdate == string.Empty)




...{


this.m_strUpdate = "[" + name + "]=" + val;


}


else




...{


this.m_strUpdate += ",[" + name + "]=" + val;


}


}




protected override string ToStr




...{




get ...{ return "UPDATE [" + base.TableName + "] SET " + this.m_strUpdate; }


}




protected override void auxClear()




...{


this.m_strUpdate = string.Empty;


}


}




private class Select : BaseClause




...{


private string m_strSelect;




public override void Add(string name, object alis)




...{


if (alis == null)




...{


this.Add(name, name, false);


}


else




...{


this.Add(name, alis.ToString(), false);


}


}




private void Add(string name, string alis, bool isref)




...{


if (this.m_strSelect == string.Empty)




...{


this.m_strSelect = "[" + name + "] as [" + alis + "]";


}


else




...{


this.m_strSelect += ",[" + name + "] as [" + alis + "]";


}


}




protected override string ToStr




...{


get




...{


if (this.m_strSelect == string.Empty)




...{


this.m_strSelect = "*";


}


return "SELECT " + this.m_strSelect + " FROM [" + base.TableName + "]";


}


}




protected override void auxClear()




...{


this.m_strSelect = string.Empty;


}


}




private class Where




...{


private string m_strWhere;




public Where()




...{


this.Clear();


}




public void Add(string name, object val)




...{


if (val == null)




...{


this.Add(name, "null", false);


}


else




...{


this.Add(name, val.ToString(), val is string || val is DateTime);


}


}




private void Add(string name, string val, bool isref)




...{


if (isref)




...{


val = "'" + val + "'";


}


if (this.m_strWhere == string.Empty)




...{


this.m_strWhere = "[" + name + "]=" + val;


}


else




...{


this.m_strWhere += " and [" + name + "]=" + val;


}


}




public override string ToString()




...{


string strRet = string.Empty;


if (this.m_strWhere != string.Empty)




...{


strRet = " Where " + this.m_strWhere;


}


return strRet;


}




public void Clear()




...{


this.m_strWhere = string.Empty;


}


}




#endregion




}