XML - Query Engine

This is the xml file which consist the Select Query in xml format,


<query>
<select> <column><field>Uid <alias>UserId <column><field>Pwd <alias>Password <column> <field>City <alias>City</select>
<from>
<table>Users <tbody></tbody></table></from>
<where>
<condetion>
<field>Uid</field>
<operator>!=</operator>

<parameterbind type="NVarchar">@userid</parameterbind>
</condetion>
<boolean operator="AND"></boolean>
<condetion>
<field>City</field>
<operator>Like</operator>
<value>'S%'</value>
</condetion>
<boolean>
</where>
<sort>
<condetion>
<field>Uid</field>
<order>Asc</order>
</condetion>
</sort>
</query>"


TO Genrate Query @ runtime,
create following Classes.


namespace XMLEngine
{
class Query // This Class Object would return by Query Engine
{
private string _queryString;
private Dictionary<string,> _paramters;
List<sqlparameter> ReturnParams = new List<sqlparameter>();


public Query()
{
_queryString = "";
_paramters = new Dictionary<string,>();
}
public string QueryString
{
get { return _queryString; }
set { _queryString = value; }
}

public Dictionary<string,> Paramters
{
get { return _paramters; }
set { _paramters = value; }
}

public void BindParameters(string key,string paramValue)
{
SqlParameter sp = _paramters[key];
sp.Value = paramValue;
_paramters[key] = sp;
}

public bool HasParametrs
{
get
{
return (_paramters.Count > 0);
}
}

public Int32 CountParametrs
{
get {return _paramters.Count; }
}

public SqlParameter[] GetParameters
{
get
{
foreach (SqlParameter sp in _paramters.Values)
{
ReturnParams.Add(sp);
}
return ReturnParams.ToArray();
}
}
}
}



And Then create Engine which Create Query and Parameters List,


namespace XMLEngine
{
class QueryEngine
{
static StringBuilder sbQuery;
static XmlDocument doc;

//List<sqlparameter> params_;
Dictionary<string,sqlparameter> params_;


public QueryReader()
{
sbQuery = new StringBuilder();
doc = new XmlDocument();
params_ = new Dictionary<string,>();
}

public Query GetQuery(string XmlDocPath)
{
Query qry = new Query();
doc.Load(XmlDocPath);

WriteSelectClause();
WriteFromClause();
WriteWhereClause();
WriteOrderByClause();

qry.Paramters = params_;
qry.QueryString=sbQuery.ToString();
//Console.WriteLine(sbQuery.ToString());
//Console.ReadKey();
return qry;
}

public void GetQueryOld(string XmlDocPath)
{
XmlDocument doc = new XmlDocument();
doc.Load(XmlDocPath);

XmlNodeList Views = doc.GetElementsByTagName("View");

foreach (XmlNode Columns in Views[0])
{
XmlElement xl = (XmlElement)Columns;
//XmlNodeList ColmnList = xl.GetElementsByTagName("Column");
Console.WriteLine(xl.GetElementsByTagName("Column")[0].InnerText + "." + xl.GetElementsByTagName("Column")[1].InnerText + "." + xl.GetElementsByTagName("Column")[2].InnerText);
//foreach (XmlNode Cols in Columns.ChildNodes)
//{
// XmlElement Desc = (XmlElement)Cols;
// Console.WriteLine(Desc.InnerText);
//}
}
Console.ReadKey();
}

public void WriteSelectClause()
{
sbQuery.Append("Select ");
XmlNodeList XSelectNodeList = doc.GetElementsByTagName(Constants.NODE_NAME_VIEW);
//XmlNode XSelectNode = doc.SelectSingleNode("/Select");
foreach (XmlNode xnColName in XSelectNodeList[0])
{
XmlElement Column = (XmlElement)xnColName;
sbQuery.Append(Column.GetElementsByTagName(Constants.NODE_NAME_FIELD)[0].InnerText);
if (Column.GetElementsByTagName(Constants.NODE_NAME_FIELD)[0].InnerText != "*")
{
sbQuery.Append(" As " + Column.GetElementsByTagName(Constants.NODE_NAME_ALIAS)[0].InnerText);
}
sbQuery.Append(",");
}
sbQuery.Remove(sbQuery.Length - 1, 1);
}

public void WriteFromClause()
{
sbQuery.Append(" From ");

XmlNodeList XFromNodeList = doc.GetElementsByTagName(Constants.NODE_NAME_FROM);

foreach (XmlNode XFromNode in XFromNodeList)
{
XmlElement From = (XmlElement)XFromNode;
sbQuery.Append(From.GetElementsByTagName(Constants.NODE_NAME_TABLE)[0].InnerText);
}
sbQuery.Append(" ");
}

public void WriteWhereClause()
{
sbQuery.Append(" Where ");
XmlNodeList XWhereNodeList = doc.GetElementsByTagName(Constants.NODE_NAME_FILTER);
foreach (XmlNode xnCondetion in XWhereNodeList[0])
{
XmlElement Condetion = (XmlElement)xnCondetion;

if (Condetion.Name ==Constants.NODE_NAME_BOOLEAN)
{
sbQuery.Append(" "+Condetion.GetAttribute(Constants.NODE_NAME_OPERATOR)+" ");
}
else
{
foreach (XmlNode xnCondTags in Condetion.ChildNodes)
{
if (xnCondTags.Name == Constants.NODE_NAME_FIELD)
{
sbQuery.Append(" " + Condetion.GetElementsByTagName(Constants.NODE_NAME_FIELD)[0].InnerText);
}
else if (xnCondTags.Name == Constants.NODE_NAME_OPERATOR)
{
sbQuery.Append(" " + Condetion.GetElementsByTagName(Constants.NODE_NAME_OPERATOR)[0].InnerText);
}
else if (xnCondTags.Name == Constants.NODE_NAME_VALUE)
{
sbQuery.Append(" " + Condetion.GetElementsByTagName(Constants.NODE_NAME_VALUE)[0].InnerText);
}
else if (xnCondTags.Name == Constants.NODE_NAME_PARAMETERBIND)
{
XmlElement xParam=(XmlElement)xnCondTags;
sbQuery.Append(" " + Condetion.GetElementsByTagName(Constants.NODE_NAME_PARAMETERBIND)[0].InnerText);
SqlParameter sp = new SqlParameter(Condetion.GetElementsByTagName(Constants.NODE_NAME_PARAMETERBIND)[0].InnerText, SqlDbType.NVarChar);
sp.ResetSqlDbType();
//sp.UdtTypeName = xParam.GetAttribute("type");
this.params_.Add(Condetion.GetElementsByTagName(Constants.NODE_NAME_FIELD)[0].InnerText, sp);
}
}
}



}

}

public void WriteOrderByClause()
{
sbQuery.Append(" Order By ");
XmlNodeList XSortNodeList = doc.GetElementsByTagName(Constants.NODE_NAME_SORT);

foreach (XmlNode xnCondetion in XSortNodeList[0])
{
XmlElement Condetion = (XmlElement)xnCondetion;
//sbQuery.Append(Condetion.InnerText+"-----");
sbQuery.Append(" " + Condetion.GetElementsByTagName(Constants.NODE_NAME_FIELD)[0].InnerText);
sbQuery.Append(" " + Condetion.GetElementsByTagName(Constants.NODE_NAME_ORDER)[0].InnerText);
sbQuery.Append(",");
}
sbQuery.Remove(sbQuery.Length - 1, 1);
}

}
}

And All used Constant Value would fetch from This Static Class.

namespace XMLEngine
{
public static class Constants
{
public const string
NODE_NAME_DOCUMENT_ELEMENT = "Query",
NODE_NAME_VIEW = "Select",
NODE_NAME_FROM = "From",
NODE_NAME_FILTER = "Where",
NODE_NAME_PARAMETERBIND = "ParameterBind",
NODE_NAME_SORT = "Sort",
NODE_NAME_CONDITION = "Condition",
NODE_NAME_TABLE = "Table",
NODE_NAME_FIELD = "Field",
NODE_NAME_ALIAS = "Alias",
NODE_NAME_COLUMN = "Column",
NODE_NAME_BOOLEAN = "Boolean",
NODE_NAME_OPERATOR = "Operator",
NODE_NAME_GROUPING = "Grouping",
NODE_NAME_GROUP = "Group",
NODE_NAME_ASCENDING = "Asc",
NODE_NAME_DESCENDING = "Desc",
NODE_NAME_VALUE = "Value",
NODE_NAME_AND = "And",
NODE_NAME_OR = "Or",
NODE_NAME_NOT = "Not",
NODE_NAME_ORDER = "Order";

public const string
DEFAULT_NAME_ROW_INDEX_FIELD = "rowIndex";

public const int
DEFAULT_PAGE_SIZE = 10;
}
}