Re: XmlQuery and GOB

["Gerhard Dieringer" <DieringG eba-haus de>]

>>> Vivien Malerba <malerba gears linuxave net> 09.10.2000  18.14 Uhr >>>
> ...
> However, from what I can understand from the .gob files, I agree with what
> you propose. If you have some time and want t go further with your ideas,
> no problem with me!
> ...

Hi Vivien,

I startet implementing XML-Query (with Insert, because it's less complex than select)

Object hierarchy:

Xml:Query:Item                  (abstract base class, derived from GtkObject)
      |
      +-- Xml:Query:Target
      |
      +-- Xml:Query:View
      |
      +-- Xml:Query:Table
      |
      +-- Xml:Query:Value
      |
      +-- Xml:Query:Field
      |
      +-- Xml:Query:Const
      |
      +-- Xml:Query:List         (may get changed to an abstract base class)
      |
      +-- Xml:Query:Query        (abstract base class)
      |         |
      |         +-- Xml:Query:Select
      |         |
      |         +-- Xml:Query:Insert
     ...       ...


The API has four groups of methods:
1.) create from DOM-tree (DOM-tree is created by libxml from XML doc)
2.) create from text
3.) render to XML (the reverse of the first)
4.) render to SQL


The groups 1, 3, and 4 are rather simple and consist of one single function each (right?)
1.) XmlQueryItem *xml_query_create_from_node(xmlNode *node)
3.) gchar *xml_query_to_xml(XmlQueryItem *item)
4.) gchar *xml_query_to_sql(XmlQueryItem *item)


group 2 is rather complex and allows the construction of a query step by step
example: 
SQL: 
INSERT INTO tab_a (ival, sval) VALUES (1,'abc')

XML:
<query>
  <insert>
    <target>
      <table id="t1" name="tab_a"/>
    </target>
    <dest>
      <field source="t1" name="ival"/>
      <field source="t1" name="sval"/>
    </dest>
    <valuelist>
      <value>
        <const value="1" type="int"/>
      </value>
      <value>
        <const value="abc" type="char"/>
      </value>
    </valuelist>
  </insert>
</query>


This query is constructed by the following sequence:

{
    XmlQueryItem *insert;

    insert = xml_query_insert_new();
    xml_query_query_add_target_from_text(XML_QUERY_QUERY(insert),
                                         XML_QUERY_TYPE_TABLE,
                                         "t1",
                                         "tab_a");
    
    xml_query_insert_add_dest_from_text(XML_QUERY_INSERT(insert), 
                                        "t1",
                                        "a");
    
    xml_query_insert_add_dest_from_text(XML_QUERY_INSERT(insert), 
                                        "t1",
                                        "b");
    
    xml_query_query_add_const_from_text(XML_QUERY_QUERY(insert), 
                                         "1", 
                                         "int",
                                         FALSE);
    
    xml_query_query_add_const_from_text(XML_QUERY_QUERY(insert), 
                                         "abc", 
                                         "char",
                                         FALSE);
}    

--------------------------------------------------------
Comments and suggestions appreciated

Gerhard