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1
29
30 package com.caucho.db.sql;
31
32 import com.caucho.db.Database;
33 import com.caucho.db.store.Transaction;
34 import com.caucho.db.table.TableIterator;
35 import com.caucho.log.Log;
36 import com.caucho.sql.SQLExceptionWrapper;
37 import com.caucho.util.CharBuffer;
38
39 import java.io.IOException  ;
40 import java.sql.SQLException ;
41 import java.util.Iterator ;
42 import java.util.logging.Logger ;
43
44 public class SelectQuery extends Query {
45 private static final Logger log = Log.open(SelectQuery.class);
46
47 private Expr []_results;
48 private String []_resultNames;
49
50 private boolean []_groupFields;
51
52 private Order _order;
53
54 SelectQuery(Database db, String sql)
55 throws SQLException
56 {
57 super(db, sql);
58 }
59
60 SelectQuery(Database db, String sql, FromItem []fromItems)
61 throws SQLException
62 {
63 super(db, sql, fromItems);
64 }
65
66 void setResults(Expr []resultExprs)
67 throws SQLException
68 {
69 _results = new Expr[resultExprs.length];
70
71 for (int i = 0; i < resultExprs.length; i++) {
72 _results[i] = resultExprs[i];
73 }
74
75 setDataFields(resultExprs.length);
76 }
77
78 Expr []getResults()
79 {
80 return _results;
81 }
82
83
86 public void setGroupResult(int index)
87 {
88 if (_groupFields == null)
89 _groupFields = new boolean[_results.length];
90
91 _groupFields[index] = true;
92 }
93
94 protected void bind()
95 throws SQLException
96 {
97 super.bind();
98
99 for (int i = 0; i < _results.length; i++) {
100 _results[i] = _results[i].bind(this);
101 }
102
103 if (isGroup()) {
104 for (int i = 0; i < _results.length; i++) {
105 if (isGroup() && ! (_results[i] instanceof GroupExpr))
106 _results[i] = new GroupResultExpr(i, _results[i]);
107 }
108 }
109
110 for (int i = 0; i < _results.length; i++) {
111 _results[i] = _results[i].bind(this);
112 }
113
114 _resultNames = new String [_results.length];
115
116 for (int i = 0; i < _resultNames.length; i++)
117 _resultNames[i] = _results[i].getName();
118 }
119
120 void setOrder(Order order)
121 {
122 _order = order;
123 }
124
125
128 public boolean isSelect()
129 {
130 return true;
131 }
132
133
136 Class getType()
137 {
138 if (_results.length == 1)
139 return _results[0].getType();
140 else
141 return Object .class;
142 }
143
144
147 public void execute(QueryContext context, Transaction xa)
148 throws SQLException
149 {
150 SelectResult result = SelectResult.create(_results, _order);
151 FromItem []fromItems = getFromItems();
152 TableIterator []rows = null;
153
154 try {
155 rows = result.initRows(fromItems);
156 context.init(xa, rows, isReadOnly());
157
158 if (isGroup())
159 executeGroup(result, rows, context, xa);
160 else
161 execute(result, rows, context, xa);
162
163 result.initRead();
164
165 context.setResult(result);
166 } catch (IOException e) {
167 throw new SQLExceptionWrapper(e);
168 } finally {
169 context.unlock();
172
173 if (rows != null)
174 freeRows(rows, rows.length);
175 }
176 }
177
178
181 private void execute(SelectResult result,
182 TableIterator []rows,
183 QueryContext context,
184 Transaction xa)
185 throws SQLException , IOException
186 {
187 FromItem []fromItems = getFromItems();
188 int rowLength = fromItems.length;
189
190 if (start(rows, rowLength, context, xa)) {
191 do {
192 result.startRow();
193 for (int i = 0; i < _results.length; i++) {
194 _results[i].evalToResult(context, result);
195 }
196 } while (nextTuple(rows, rowLength, context, xa));
197 }
198 }
199
200 private void executeGroup(SelectResult result,
201 TableIterator []rows,
202 QueryContext context,
203 Transaction transaction)
204 throws SQLException , IOException
205 {
206 FromItem []fromItems = getFromItems();
207 int rowLength = fromItems.length;
208
209 Expr []results = _results;
210 int resultsLength = results.length;
211
212
216
217 if (_groupFields == null)
218 _groupFields = new boolean[0];
219
220 boolean []groupByFields = _groupFields;
221 int groupByLength = _groupFields.length;
222
223 if (start(rows, rowLength, context, transaction)) {
224 do {
225 context.initGroup(getDataFields(), _groupFields);
226
227 for (int i = 0; i < groupByLength; i++) {
228 if (groupByFields[i])
229 results[i].evalGroup(context);
230 }
231
232 context.selectGroup();
233
234 for (int i = 0; i < resultsLength; i++) {
235 if (! (i < groupByLength && groupByFields[i]))
236 results[i].evalGroup(context);
237 }
238 } while (nextTuple(rows, rowLength, context, transaction));
239 }
240
241 Iterator<GroupItem> groupIter = context.groupResults();
242
243 while (groupIter.hasNext()) {
244 GroupItem item = groupIter.next();
245
246 context.setGroupItem(item);
247
248 result.startRow();
249 for (int i = 0; i < results.length; i++) {
250 results[i].evalToResult(context, result);
251 }
252 }
253 }
254
255 public String toString()
256 {
257 CharBuffer cb = CharBuffer.allocate();
258 cb.append("SelectQuery[");
259 cb.append("SELECT ");
260 for (int i = 0; i < _results.length; i++) {
261 if (i != 0)
262 cb.append(",");
263 cb.append(_results[i]);
264 }
265 cb.append(" FROM ");
266
267 FromItem []fromItems = getFromItems();
268 for (int i = 0; i < fromItems.length; i++) {
269 if (i != 0)
270 cb.append(",");
271 cb.append(fromItems[i]);
272 }
273
274 if (_whereExpr != null) {
275 cb.append(" WHERE " + _whereExpr);
276 }
277 cb.append("]");
278
279 return cb.close();
280 }
281 }
282 |
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