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34 package smallsql.database;
35
36
37
40 final class UnionAll extends DataSource {
41
42 private final DataSources dataSources = new DataSources();
43 private int dataSourceIdx;
44 private DataSource currentDS;
45 private int row;
46
47
48 void addDataSource(DataSource ds){
49 dataSources.add(ds);
50 currentDS = dataSources.get(0);
51 }
52
53
54
59
60 boolean init(SSConnection con) throws Exception  {
61 boolean result = false;
62 int colCount = -1;
63 for(int i=0; i<dataSources.size(); i++){
64 DataSource ds = dataSources.get(i);
65 result |= ds.init(con);
66 int nextColCount = ds.getTableView().columns.size();
67 if(colCount == -1)
68 colCount = nextColCount;
69 else
70 if(colCount != nextColCount)
71 throw Utils.createSQLException("Different SELECT of the UNION have different column count:"+colCount+" and "+nextColCount);
72 }
73 return result;
74 }
75
76
77 final boolean isNull(int colIdx) throws Exception {
78 return currentDS.isNull(colIdx);
79 }
80
81
82 final boolean getBoolean(int colIdx) throws Exception {
83 return currentDS.getBoolean(colIdx);
84 }
85
86
87 final int getInt(int colIdx) throws Exception {
88 return currentDS.getInt(colIdx);
89 }
90
91
92 final long getLong(int colIdx) throws Exception {
93 return currentDS.getLong(colIdx);
94 }
95
96
97 final float getFloat(int colIdx) throws Exception {
98 return currentDS.getFloat(colIdx);
99 }
100
101
102 final double getDouble(int colIdx) throws Exception {
103 return currentDS.getDouble(colIdx);
104 }
105
106
107 final long getMoney(int colIdx) throws Exception {
108 return currentDS.getMoney(colIdx);
109 }
110
111
112 final MutableNumeric getNumeric(int colIdx) throws Exception {
113 return currentDS.getNumeric(colIdx);
114 }
115
116
117 final Object getObject(int colIdx) throws Exception {
118 return currentDS.getObject(colIdx);
119 }
120
121
122 final String getString(int colIdx) throws Exception {
123 return currentDS.getString(colIdx);
124 }
125
126
127 final byte[] getBytes(int colIdx) throws Exception {
128 return currentDS.getBytes(colIdx);
129 }
130
131
132 final int getDataType(int colIdx) {
133 return currentDS.getDataType(colIdx);
134 }
135
136
137 TableView getTableView(){
138 return currentDS.getTableView();
139 }
140
141
142
143
148
149 final boolean isScrollable(){
150 return false; }
152
153
154 final void beforeFirst() throws Exception {
155 dataSourceIdx = 0;
156 currentDS = dataSources.get(0);
157 currentDS.beforeFirst();
158 row = 0;
159 }
160
161
162 final boolean first() throws Exception {
163 dataSourceIdx = 0;
164 currentDS = dataSources.get(0);
165 boolean b = currentDS.first();
166 row = b ? 1 : 0;
167 return b;
168 }
169
170
171 final boolean next() throws Exception {
172 boolean n = currentDS.next();
173 row++;
174 if(n) return true;
175 while(dataSources.size() > dataSourceIdx+1){
176 currentDS = dataSources.get(++dataSourceIdx);
177 currentDS.beforeFirst();
178 n = currentDS.next();
179 if(n) return true;
180 }
181 row = 0;
182 return false;
183 }
184
185
186 final void afterLast() throws Exception {
187 dataSourceIdx = dataSources.size()-1;
188 currentDS = dataSources.get(dataSourceIdx);
189 currentDS.afterLast();
190 row = 0;
191 }
192
193
194 final int getRow() throws Exception {
195 return row;
196 }
197
198
199 private final int getBitCount(){
200 int size = dataSources.size();
201 int bitCount = 0;
202 while(size>0){
203 bitCount++;
204 size >>= 1;
205 }
206 return bitCount;
207 }
208
209
210 final long getRowPosition() {
211 int bitCount = getBitCount();
212 return dataSourceIdx | currentDS.getRowPosition() << bitCount;
213 }
214
215
216 final void setRowPosition(long rowPosition) throws Exception {
217 int bitCount = getBitCount();
218 int mask = 0xFFFFFFFF >>> (32 - bitCount);
219 dataSourceIdx = (int)rowPosition & mask;
220 currentDS = dataSources.get(dataSourceIdx);
221 currentDS.setRowPosition( rowPosition >> bitCount );
222 }
225
226
227 final boolean rowInserted(){
228 return currentDS.rowInserted();
229 }
230
231
232 final boolean rowDeleted(){
233 return currentDS.rowDeleted();
234 }
235
236
237 final void nullRow() {
238 currentDS.nullRow();
239 row = 0;
240 }
241
242
243 final void noRow() {
244 currentDS.noRow();
245 row = 0;
246 }
247
248
249 final void execute() throws Exception {
250 for(int i=0; i<dataSources.size(); i++){
251 dataSources.get(i).execute();
252 }
253 }
254
255 }
256 |
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