1 mike  1.2 //%/////////////////////////////////////////////////////////////////////////////
  2           //

  3 kumpf 1.4 // Copyright (c) 2000, 2001, 2002 BMC Software, Hewlett-Packard Company, IBM,

  4 mike  1.2 // The Open Group, Tivoli Systems
  5           //
  6           // Permission is hereby granted, free of charge, to any person obtaining a copy

  7 kumpf 1.4 // of this software and associated documentation files (the "Software"), to
  8           // deal in the Software without restriction, including without limitation the
  9           // rights to use, copy, modify, merge, publish, distribute, sublicense, and/or

 10 mike  1.2 // sell copies of the Software, and to permit persons to whom the Software is
 11           // furnished to do so, subject to the following conditions:
 12           // 

 13 kumpf 1.4 // THE ABOVE COPYRIGHT NOTICE AND THIS PERMISSION NOTICE SHALL BE INCLUDED IN

 14 mike  1.2 // ALL COPIES OR SUBSTANTIAL PORTIONS OF THE SOFTWARE. THE SOFTWARE IS PROVIDED
 15           // "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT

 16 kumpf 1.4 // LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
 17           // PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 18           // HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN

 19 mike  1.2 // ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 20           // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 21           //
 22           //==============================================================================
 23           //
 24           // Author: Mike Brasher (mbrasher@bmc.com)
 25           //
 26           // Modified By:
 27           //
 28           //%/////////////////////////////////////////////////////////////////////////////
 29           
 30           #ifndef Pegasus_WQLSelectStatement_h
 31           #define Pegasus_WQLSelectStatement_h
 32           
 33           #include <Pegasus/Common/Config.h>

 34 kumpf 1.5 #include <Pegasus/Common/ArrayInternal.h>

 35 mike  1.2 #include <Pegasus/Common/String.h>
 36           #include <Pegasus/WQL/WQLOperation.h>
 37           #include <Pegasus/WQL/WQLOperand.h>
 38           #include <Pegasus/WQL/WQLPropertySource.h>
 39           
 40           PEGASUS_NAMESPACE_BEGIN
 41           
 42           /** This class represents a compiled WQL1 select statement. 
 43           
 44               An instance of WQLSelectStatement is passed to WQLParser::parse() which
 45               parses the WQL1 SELECT statement and initializes the WQLSelectStatement
 46               instance. A WQL1 SELECT statement has the following form:
 47           
 48               <pre>
 49           	SELECT &lt;property&gt;...
 50           	FROM &lt;class name&gt;
 51           	WHERE &lt;where clause&gt;
 52               </pre>
 53           
 54               There are methods for obtaining the various elements of the select
 55               statement.
 56 mike  1.2     
 57               The components of the where clause are stored in two arrays: one for
 58               operands and one for operators (these are placed in proper order by the
 59               YACC parser). Evaluation is performed using a Boolean stack. See the
 60               implementation of evaluateWhereClause() for details.
 61           */
 62           class PEGASUS_WQL_LINKAGE WQLSelectStatement
 63           {
 64           public:
 65           
 66               /** Default constructor. 
 67               */
 68               WQLSelectStatement();
 69           
 70               /** Destructor.
 71               */
 72               ~WQLSelectStatement();
 73           
 74               /** Clears all data members of this object.
 75               */
 76               void clear();
 77 mike  1.2 
 78               /** Accessor.
 79               */
 80               const String& getClassName() const
 81               {
 82           	return _className;
 83               }
 84           
 85               /** Modifier. This method should not be called by the user (only by the
 86           	parser).
 87               */
 88               void setClassName(const String& className)
 89               {
 90           	_className = className;
 91               }
 92           
 93               /** Returns the number of property names which were indicated in the
 94           	selection list.
 95               */
 96               Uint32 getSelectPropertyNameCount() const
 97               {
 98 mike  1.2 	return _selectPropertyNames.size();
 99               }
100           
101               /** Gets the i-th selected property name in the list.
102               */

103 kumpf 1.3     const String& getSelectPropertyName(Uint32 i) const

104 mike  1.2     {
105           	return _selectPropertyNames[i];
106               }
107           
108               /** Appends a property name to the property name list. This user should
109           	not call this method; it should only be called by the parser.
110               */
111               void appendSelectPropertyName(const String& x)
112               {
113           	_selectPropertyNames.append(x);
114               }
115           
116               /** Returns the number of unique property names from the where clause.
117               */
118               Uint32 getWherePropertyNameCount() const
119               {
120           	return _wherePropertyNames.size();
121               }
122           
123               /** Gets the i-th unique property appearing in the where clause.
124               */

125 kumpf 1.3     const String& getWherePropertyName(Uint32 i) const

126 mike  1.2     {
127           	return _wherePropertyNames[i];
128               }
129           
130               /** Appends a property name to the where property name list. This user 
131           	should not call this method; it should only be called by the parser.
132           
133           	@param x name of the property.
134           	@return false if a property with that name already exists.
135               */
136               Boolean appendWherePropertyName(const String& x);
137           
138               /** Appends an operation to the operation array. This method should only
139           	be called by the parser itself.
140               */
141               void appendOperation(WQLOperation x)
142               {
143           	_operations.append(x);
144               }
145           
146               /** Appends an operand to the operation array. This method should only
147 mike  1.2 	be called by the parser itself.
148               */
149               void appendOperand(const WQLOperand& x)
150               {
151           	_operands.append(x);
152               }
153           
154               /** Returns true if this class has a where clause.
155               */
156               Boolean hasWhereClause() const
157               {
158           	return _operations.size() != 0;
159               }
160           
161               /** Evalautes the where clause using the symbol table to resolve symbols.
162               */
163               Boolean evaluateWhereClause(const WQLPropertySource* source) const;
164           
165               /** Prints out the members of this class.
166               */
167               void print() const;
168 mike  1.2 
169           private:
170           
171               //
172               // The name of the target class. For example:
173               //
174               //     SELECT * 
175               //     FROM TargetClass
176               //     WHERE ...
177               //
178           
179               String _className;
180           
181               //
182               // The list of property names being selected. For example, see "firstName",
183               // and "lastName" below.
184               //
185               //     SELECT firstName, lastName 
186               //     FROM TargetClass
187               //     WHERE ...
188               //
189 mike  1.2 
190               Array<String> _selectPropertyNames;
191           
192               //
193               // The unique list of property names appearing in the WHERE clause.
194               // Although a property may occur many times in the WHERE clause, it will
195               // only appear once in this list.
196               //
197           
198               Array<String> _wherePropertyNames;
199           
200               //
201               // The list of operations encountered while parsing the WHERE clause.
202               // Consider this query:
203               //
204               //     SELECT *
205               //     FROM TargetClass
206               //     WHERE count > 10 OR peak < 20 AND state = "OKAY"
207               //
208               // This would generate the following stream of WQLOperations:
209               //
210 mike  1.2     //     WQL_GT
211               //     WQL_LT
212               //     WQL_EQ
213               //     WQL_AND
214               //     WQL_OR
215               //
216           
217               Array<WQLOperation> _operations;
218           
219               // 
220               // The list of operands encountered while parsing the WHERE clause. They
221               // query just above would generate the following stream of operands:
222               //
223               //     count, 10, peak, 20, state, "OKAY"
224               //
225           
226               Array<WQLOperand> _operands;
227           
228               void f() const { }
229           };
230           
231 mike  1.2 PEGASUS_NAMESPACE_END
232           
233           #endif /* Pegasus_WQLSelectStatement_h */