'$RCSfile: query.xsd,v $'
       Copyright: 2003 Partnership for Biodiversity Informatics
         Project: http://seek.ecoinformatics.org/
        '$Author: tao $'
          '$Date: 2008-04-23 16:25:50 $'
      '$Revision: 1.10 $'
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.
    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.
    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
    
    
    
    
        
            An XML-based query structure for combining XPath 
            pattern matching expressions using logical operators.
            
        
        
            
                
                    The namespace element identifies
                        the scope for the query by giving one or more 
                        namespaces to which the query conditions should be 
                        applied.  For example, to query EML documents, one 
                        would indicate a namespace of 
                        "eml://ecoinformatics.org/eml-2.0.0". When more than
                        one namespace is given, then the query conditions 
                        should be applied to all of those document types within
                        the EcoGrid repository node.
                        
                
                
                    
                        
                            
                        
                    
                
            
            
                
                    An optional limited XPath expression that
                    defines a field that should be returned in the resultset 
                    document.  The result record constructed will contain a 
                    well-formed xml file that combines all of the returnfields 
                    into a single tree structure.  If a returnfield is specified
                    as a leaf node that is a SimpleType, the value and all 
                    parent elements leading to that value will be included in 
                    the result.  If a specified returnfield is not a leaf node, 
                    then all element and value content below that node will be 
                    included in the result along with the parent elements 
                    leading to the matched node.
                    
                
            
            
                
                    An optional title that names and 
                    describes the query.
                
            
            
                
                
                
            
            
        
        
        
    
    
        
            A type of logical operator that requires all of 
            its child conditions to evaluate to true in order for the whole 
            clause to evaluate to true.
        
        
            
            
            
        
    
    
        
            A type of logical operator that evaluates to true 
            if any one or more of its child conditions evaluate to true.
            
        
        
            
            
            
        
    
    
        
            The condition represents a portion of the query
            that restricts the set of documents that match the query.  The
            content of the condition element is the value that should be 
            matched. The symbol '%' should be interpreted as a wildcard that 
            matches any character.  The "operator" determines how the match is 
            performed (e.g., whether numeric equality or string equality is 
            used), and the "concept" determines the field to which the 
            restriction is applied (e.g., for XML sources this will be a 
            relative or absolute path expression).
            
        
        
            
                
                
            
        
    
    
        
            The OperatorType defines the set of allowable 
            values for the match operator in a condition.  The match operator
            determines the semantics of how matches occur for that condition.
            
        
        
            
                
                    Matches string containing value exactly
                    
                
            
            
                
                    Matches string not containing value
                    
                
            
            
                
                    Matches if numerically equal to value
                    
                
            
            
                
                    Matches if numerically not equal to value
                    
                
            
            
                
                    Matches if less than value
                    
                
            
            
                
                    Matches if less than or equal to value
                    
                
            
            
                
                    Matches if greater than value
                    
                
            
            
                
                    Matches if greater than or equal to value
                    
                
            
        
    
    
        
            A simple type that provides a restricted version 
            of standard XPath expressions.  These expressions are the valid path 
			expressions that can be used to express condition concepts and 
			returnfield paths, and represent a subset of the full XPath syntax.