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1
10
11 package com.triactive.jdo.store;
12
13 import java.util.ArrayList  ;
14 import java.util.HashMap ;
15 import java.util.Iterator ;
16 import javax.jdo.JDOFatalInternalException;
17
18
19 public class QueryStatement
20 {
21 protected final StoreManager storeMgr;
22 protected final DatabaseAdapter dba;
23 protected final SQLIdentifier defaultRangeVar;
24 protected final TableExpression initialTableExpr;
25
26 protected HashMap tableExprsByRangeVar = new HashMap ();
27 protected boolean distinctResults = false;
28 protected ArrayList selected = new ArrayList ();
29 protected ArrayList joins = new ArrayList ();
30 protected BooleanExpression whereExpr = null;
31 protected StatementText orderByList = null;
32 protected StatementText stmtText = null;
33
34 public QueryStatement(Table initialTable)
35 {
36 this.storeMgr = initialTable.getStoreManager();
37 this.dba = storeMgr.getDatabaseAdapter();
38
39 defaultRangeVar = new TableIdentifier(dba, "this");
40
41 initialTableExpr = newTableExpression(initialTable, defaultRangeVar);
42 tableExprsByRangeVar.put(defaultRangeVar, initialTableExpr);
43 }
44
45 public QueryStatement(Table initialTable, SQLIdentifier initialRangeVar)
46 {
47 this.storeMgr = initialTable.getStoreManager();
48 this.dba = storeMgr.getDatabaseAdapter();
49
50 defaultRangeVar = new TableIdentifier(dba, "this");
51
52 initialTableExpr = newTableExpression(initialTable, initialRangeVar);
53 tableExprsByRangeVar.put(initialRangeVar, initialTableExpr);
54 }
55
56 protected void assertNotFrozen()
57 {
58 if (stmtText != null)
59 throw new JDOFatalInternalException("A query statement cannot be modified after being output");
60 }
61
62 public StoreManager getStoreManager()
63 {
64 return storeMgr;
65 }
66
67 public TableExpression getTableExpression(SQLIdentifier rangeVar)
68 {
69 return (TableExpression)tableExprsByRangeVar.get(rangeVar);
70 }
71
72 public TableExpression getDefaultTableExpression()
73 {
74 return getTableExpression(defaultRangeVar);
75 }
76
77 public TableExpression newTableExpression(Table mainTable, SQLIdentifier rangeVar)
78 {
79 assertNotFrozen();
80
81 TableExpression te = (TableExpression)tableExprsByRangeVar.get(rangeVar);
82
83 if (te == null)
84 {
85 te = dba.newTableExpression(this, mainTable, rangeVar);
86
87 tableExprsByRangeVar.put(rangeVar, te);
88 }
89 else
90 {
91 if (!te.getMainTable().equals(mainTable))
92 throw new JDOFatalInternalException("Range variable " + rangeVar + " already in use in query: " + this);
93 }
94
95 return te;
96 }
97
98 public boolean getDistinctResults()
99 {
100 return distinctResults;
101 }
102
103 public void setDistinctResults(boolean distinctResults)
104 {
105 assertNotFrozen();
106
107 this.distinctResults = distinctResults;
108 }
109
110 public int select(Column col)
111 {
112 return select(defaultRangeVar, col);
113 }
114
115 public int select(SQLIdentifier rangeVar, Column col)
116 {
117 assertNotFrozen();
118
119 String columnID = getColumn(rangeVar, col).toString();
120
121 if (!selected.contains(columnID))
122 selected.add(columnID);
123
124 return selected.indexOf(columnID) + 1;
125 }
126
127 public int columnsSelected()
128 {
129 return selected.size();
130 }
131
132 public QueryColumn getColumn(Column col)
133 {
134 return getColumn(defaultRangeVar, col);
135 }
136
137 public QueryColumn getColumn(SQLIdentifier rangeVar, Column col)
138 {
139 TableExpression te = (TableExpression)tableExprsByRangeVar.get(rangeVar);
140
141 if (te == null)
142 throw new JDOFatalInternalException("No such range variable: " + rangeVar);
143
144 return getColumn(te, col);
145 }
146
147 public QueryColumn getColumn(TableExpression te, Column col)
148 {
149 return new QueryColumn(te, col);
150 }
151
152 public void innerJoin(QueryColumn from, QueryColumn to)
153 {
154 assertNotFrozen();
155
156 joins.add(new Join("INNER JOIN", from, to));
157 }
158
159 public void leftOuterJoin(QueryColumn from, QueryColumn to)
160 {
161 assertNotFrozen();
162
163 joins.add(new Join("LEFT OUTER JOIN", from, to));
164 }
165
166 public void rightOuterJoin(QueryColumn from, QueryColumn to)
167 {
168 assertNotFrozen();
169
170 joins.add(new Join("RIGHT OUTER JOIN", from, to));
171 }
172
173 public void andCondition(BooleanExpression condition)
174 {
175 assertNotFrozen();
176
177 if (whereExpr == null)
178 whereExpr = condition;
179 else
180 whereExpr = whereExpr.and(condition);
181 }
182
183 public void setOrdering(SQLExpression[] exprs, boolean[] descending)
184 {
185 assertNotFrozen();
186
187 boolean needsSelect = dba.includeOrderByColumnsInSelect();
188
189 orderByList = new StatementText();
190
191 for (int i = 0; i < exprs.length; ++i)
192 {
193 if (i > 0)
194 orderByList.append(',');
195
196 orderByList.append(exprs[i]);
197
198 if (descending[i])
199 orderByList.append(" DESC");
200
201 if (needsSelect)
202 {
203 Iterator j = exprs[i].toStatementText().getReferencedColumns().iterator();
204
205 while (j.hasNext())
206 {
207 String columnRef = j.next().toString();
208
209 if (!selected.contains(columnRef))
210 selected.add(columnRef);
211 }
212 }
213 }
214 }
215
216 public StatementText toStatementText()
217 {
218 if (stmtText == null)
219 {
220 stmtText = new StatementText("SELECT ");
221
222 if (distinctResults)
223 stmtText.append("DISTINCT ");
224
225 Iterator i = selected.iterator();
226
227 while (i.hasNext())
228 {
229 stmtText.append(i.next());
230
231 if (i.hasNext())
232 stmtText.append(',');
233 }
234
235 stmtText.append(" FROM ").append(initialTableExpr);
236
237 i = joins.iterator();
238
239 while (i.hasNext())
240 stmtText.append(' ').append(i.next());
241
242 if (whereExpr != null)
243 stmtText.append(" WHERE ").append(whereExpr);
244
245 if (orderByList != null)
246 stmtText.append(" ORDER BY ").append(orderByList);
247 }
248
249 return stmtText;
250 }
251
252 public String toString()
253 {
254 return toStatementText().toString();
255 }
256
257 protected static class Join
258 {
259 private final String type;
260 private final TableExpression te;
261 private final String condition;
262
263 public Join(String type, QueryColumn from, QueryColumn to)
264 {
265 this.type = type;
266
267
281 te = to.te;
282 condition = from + " = " + to;
283 }
284
285 public String toString()
286 {
287 return type + " " + te + " ON " + condition;
288 }
289 }
290
291 public class QueryColumn
292 {
293 public final TableExpression te;
294 public final Column column;
295
296 private QueryColumn(TableExpression te, Column column)
297 {
298 this.te = te;
299 this.column = column;
300 }
301
302 public QueryStatement getQueryStatement()
303 {
304 return QueryStatement.this;
305 }
306
307 public int hashCode()
308 {
309 return te.hashCode() ^ column.hashCode();
310 }
311
312 public boolean equals(Object o)
313 {
314 if (o == this)
315 return true;
316
317 if (!(o instanceof QueryColumn))
318 return false;
319
320 QueryColumn qsc = (QueryColumn)o;
321
322 return te.equals(qsc.te) && column.equals(qsc.column);
323 }
324
325 public String toString()
326 {
327 return te.referenceColumn(column);
328 }
329 }
330 }
331 |
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