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1
5 package org.h2.table;
6
7 import java.sql.SQLException  ;
8
9 import org.h2.command.Prepared;
10 import org.h2.command.dml.Query;
11 import org.h2.engine.Session;
12 import org.h2.expression.Expression;
13 import org.h2.index.Index;
14 import org.h2.index.IndexType;
15 import org.h2.index.ViewIndex;
16 import org.h2.message.Message;
17 import org.h2.result.Row;
18 import org.h2.schema.Schema;
19 import org.h2.util.ObjectArray;
20 import org.h2.util.StringUtils;
21
22 public class TableView extends Table {
23
24 private String querySQL;
25 private ObjectArray tables;
26 private String [] columnNames;
27 private boolean invalid;
28 private Query viewQuery;
29 private ViewIndex index;
30
31 public TableView(Schema schema, int id, String name, String querySQL, ObjectArray params, String [] columnNames, Session session) throws SQLException {
32 super(schema, id, name, false);
33 this.querySQL = querySQL;
34 this.columnNames = columnNames;
35 index = new ViewIndex(this, querySQL, params);
36 initColumnsAndTables(session);
37 }
38
39 private void initColumnsAndTables(Session session) throws SQLException {
40 Column[] cols;
41 removeViewFromTables();
42 try {
43 Prepared p = session.prepare(querySQL);
44 if(!(p instanceof Query)) {
45 throw Message.getSyntaxError(querySQL, 0);
46 }
47 Query query = (Query)p;
48 tables = new ObjectArray(query.getTables());
49 ObjectArray expressions = query.getExpressions();
50 ObjectArray list = new ObjectArray();
51 for(int i=0; i<query.getColumnCount(); i++) {
52 Expression expr = (Expression) expressions.get(i);
53 String name = null;
54 if(columnNames != null && columnNames.length > i) {
55 name = columnNames[i];
56 }
57 if(name == null) {
58 name = expr.getAlias();
59 }
60 int type = expr.getType();
61 long precision = expr.getPrecision();
62 int scale = expr.getScale();
63 Column col = new Column(name, type, precision, scale);
64 col.setTable(this, i);
65 list.add(col);
66 }
67 cols = new Column[list.size()];
68 list.toArray(cols);
69 invalid = false;
70 if(getId() != 0) {
71 addViewToTables();
72 }
73 viewQuery = query;
74 } catch(SQLException e) {
75 tables = new ObjectArray();
78 cols = new Column[0];
79 invalid = true;
80 }
81 setColumns(cols);
82 }
83
84 public boolean getInvalid() {
85 return invalid;
86 }
87
88 public PlanItem getBestPlanItem(Session session, int[] masks) throws SQLException {
89 PlanItem item = new PlanItem();
90 item.cost = index.getCost(session, masks);
91 item.index = index;
92 return item;
93 }
94
95 public String getCreateSQL() {
96 StringBuffer buff = new StringBuffer ();
97 buff.append("CREATE FORCE VIEW ");
98 buff.append(getSQL());
99 if(comment != null) {
100 buff.append(" COMMENT ");
101 buff.append(StringUtils.quoteStringSQL(comment));
102 }
103 if(columns.length>0) {
104 buff.append('(');
105 for(int i=0; i<columns.length; i++) {
106 if(i>0) {
107 buff.append(", ");
108 }
109 buff.append(columns[i].getSQL());
110 }
111 buff.append(")");
112 }
113 buff.append(" AS\n");
114 buff.append(querySQL);
115 return buff.toString();
116 }
117
118 public void checkRename() throws SQLException {
119 }
120
121 public void lock(Session session, boolean exclusive) throws SQLException {
122 }
124
125 public void close(Session session) throws SQLException {
126 }
127
128 public void unlock(Session s) {
129 }
130
131 public boolean isLockedExclusively() {
132 return false;
133 }
134
135 public void removeIndex(String indexName) throws SQLException {
136 throw Message.getUnsupportedException();
137 }
138
139 public Index addIndex(Session session, String indexName, int indexId, Column[] cols, IndexType indexType, int headPos, String comment) throws SQLException {
140 throw Message.getUnsupportedException();
141 }
142
143 public void removeRow(Session session, Row row) throws SQLException {
144 throw Message.getUnsupportedException();
145 }
146
147 public void addRow(Session session, Row row) throws SQLException {
148 throw Message.getUnsupportedException();
149 }
150
151 public void checkSupportAlter() throws SQLException {
152 throw Message.getUnsupportedException();
154 }
155
156 public void truncate(Session session) throws SQLException {
157 throw Message.getUnsupportedException();
158 }
159
160 public int getRowCount() {
161 throw Message.getInternalError();
162 }
163
164 public boolean canGetRowCount() {
165 return false;
167 }
168
169 public boolean canDrop() {
170 return true;
171 }
172
173 public String getTableType() {
174 return Table.VIEW;
175 }
176
177 public void removeChildrenAndResources(Session session) throws SQLException {
178 removeViewFromTables();
179 super.removeChildrenAndResources(session);
180 querySQL = null;
181 index = null;
182 invalidate();
183 }
184
185 public Index getScanIndex(Session session) throws SQLException {
186 if(invalid) {
187 throw Message.getSQLException(Message.VIEW_IS_INVALID_1, getSQL());
188 }
189 PlanItem item = getBestPlanItem(session, null);
190 return item.index;
191 }
192
193 public ObjectArray getIndexes() {
194 return null;
195 }
196
197 public ObjectArray getTables() {
198 return tables;
199 }
200
201 public void recompile(Session session) throws SQLException {
202 for(int i=0; i<tables.size(); i++) {
203 Table t = (Table)tables.get(i);
204 t.removeView(this);
205 }
206 tables.clear();
207 initColumnsAndTables(session);
208 }
209
210 public long getMaxDataModificationId() {
211 if(invalid) {
212 throw Message.getInternalError();
213 }
214 if(viewQuery == null) {
215 return Long.MAX_VALUE;
216 }
217 return viewQuery.getMaxDataModificationId();
218 }
219
220 public Index getUniqueIndex() {
221 return null;
222 }
223
224 private void removeViewFromTables() {
225 if(tables != null) {
226 for(int i=0; i<tables.size(); i++) {
227 Table t = (Table)tables.get(i);
228 t.removeView(this);
229 }
230 tables.clear();
231 }
232 }
233
234 private void addViewToTables() {
235 for(int i=0; i<tables.size(); i++) {
236 Table t = (Table)tables.get(i);
237 t.addView(this);
238 }
239 }
240
241 }
242 |
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