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1 package com.quadcap.sql;
2
3
40
41 import java.io.ByteArrayOutputStream  ;
42 import java.io.Externalizable ;
43 import java.io.IOException ;
44 import java.io.ObjectInput ;
45 import java.io.ObjectOutput ;
46
47 import java.util.Vector ;
48
49 import java.sql.ResultSet ;
50 import java.sql.SQLException ;
51
52 import com.quadcap.sql.io.ObjectInputStream;
53 import com.quadcap.sql.io.ObjectOutputStream;
54
55 import com.quadcap.sql.index.Btree;
56 import com.quadcap.sql.index.Comparator;
57
58
63 public abstract class ForeignKeyConstraint
64 extends Constraint
65 implements Externalizable
66 {
67 String fTableName;
68 Vector fColNames;
69 Table fTable;
70 UniqueConstraint fConstraint;
71 int[] fCols;
72 transient Comparator compare;
73
74
77 public ForeignKeyConstraint() {}
78
79 public ForeignKeyConstraint(String name, String fTableName) {
80 super(name);
81 this.fTableName = fTableName;
82 }
83
84 public ForeignKeyConstraint(String name, Vector colNames,
85 String fTableName, Vector fColNames) {
86 super(name, colNames);
87 this.fTableName = fTableName;
88 this.fColNames = fColNames;
89 }
90
91
94 public void resetColumns() throws SQLException {
95 super.resetColumns();
96 fCols = null;
97 }
98
99 public void checkInsert(Session session, Row row)
100 throws SQLException , IOException
101 {
102 }
103
104 public void applyInsert(Session session, Row row, long rowId,
105 Constraint activeIndex)
106 throws SQLException , IOException
107 {
108 }
109
110 public void checkUpdate(Session session, Row row, long rowId)
111 throws SQLException , IOException
112 {
113 }
114
115 public void applyUpdate(Session session, byte[] oldKey, Row row,
116 Row oldRow, long rowId, Constraint activeIndex)
117 throws SQLException , IOException
118 {
119 }
120
121 public void checkDelete(Session session, Row row, long rowId)
122 throws SQLException , IOException
123 {
124 }
125
126 public void applyDelete(Session session, Row row, long rowId,
127 Constraint activeIndex)
128 throws SQLException , IOException
129 {
130 }
131
132
135 public final boolean isDeferred() {
136 return (spec & INIT_DEFERRED) != 0;
137 }
138
139 final Comparator getComparator() throws SQLException {
140 if (compare == null) compare = new Key(getColumns().length);
141 return compare;
142 }
143
144
147 public byte[] makeKey(Session session, Row row)
148 throws SQLException
149 {
150 return makeKey(row, getColumns());
151 }
152
153
156 public byte[] makeFKey(Session session, Row row)
157 throws IOException , SQLException
158 {
159 return makeKey(row, getFCols(session.getDatabase()));
160 }
161
162 private final byte[] makeKey(Row row, int[] k) throws SQLException {
163 return Key.makeKey(null, row, k, 0, false);
164 }
165
166 public void setForeignColumn(String name) {
167 fColNames = new Vector ();
168 fColNames.addElement(name);
169 }
170
171 public void readExternal(ObjectInput in)
172 throws IOException , ClassNotFoundException
173 {
174 super.readExternal(in);
175 fTableName = (String )in.readObject();
176 fColNames = (Vector )in.readObject();
177 }
178
179 public void writeExternal(ObjectOutput out) throws IOException {
180 super.writeExternal(out);
181 out.writeObject(fTableName);
182 out.writeObject(fColNames);
183 }
184
185 public String getFTableName() {
186 return fTableName;
187 }
188
189 public void setFTableName(String s) {
190 fTableName = s;
191 }
192
193 public Table getFTable(Database db) throws SQLException , IOException {
194 if (fTable == null) {
195 Relation t = db.getRelation(fTableName);
196 if (t == null) {
197 throw new SQLException ("No such table: " + fTableName,
198 "42000");
199 }
200 try {
201 fTable = (Table)t;
202 } catch (ClassCastException e) {
203 throw new SQLException ("Not a base table: " + fTableName,
204 "42000");
205 }
206 }
207 return fTable;
208 }
209
210
213 public void add(Session session) throws SQLException , IOException {}
214
215 abstract public void delete(Session session)
216 throws SQLException , IOException
217 ;
218
219
222 public int[] getFCols(Database db) throws SQLException , IOException {
223 if (fCols == null) {
224 if (fColNames == null) {
225 UniqueConstraint pk = getFTable(db).getPrimaryKey();
226 if (pk == null) {
227 throw new SQLException ("No primary key for table " +
228 fTable.getName());
229 }
230 fConstraint = pk;
231 fCols = pk.getColumns();
232 } else {
233 fCols = getFTable(db).mapColumns(fColNames);
234 fConstraint = fTable.getIndexForColumns(fCols);
235 }
236 }
237 return fCols;
238 }
239
240 boolean isSelfReferencing(Database db) throws IOException , SQLException {
241 boolean ret = table == getFTable(db);
242 return ret;
243 }
244
245 public String toString() {
246 StringBuffer sb = new StringBuffer (super.toString());
247 sb.append(" references " + fTableName + "(");
248 if (fColNames != null) {
249 for (int i = 0; i < fColNames.size(); i++) {
250 if (i > 0) sb.append(",");
251 sb.append(fColNames.elementAt(i).toString());
252 }
253 }
254 sb.append(')');
255 return sb.toString();
256 }
257 }
258 |
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