| 1 | /* |
| 2 | |
| 3 | Derby - Class org.apache.derby.iapi.sql.dictionary.ForeignKeyConstraintDescriptor |
| 4 | |
| 5 | Copyright 1998, 2004 The Apache Software Foundation or its licensors, as applicable. |
| 6 | |
| 7 | Licensed under the Apache License, Version 2.0 (the "License"); |
| 8 | you may not use this file except in compliance with the License. |
| 9 | You may obtain a copy of the License at |
| 10 | |
| 11 | http://www.apache.org/licenses/LICENSE-2.0 |
| 12 | |
| 13 | Unless required by applicable law or agreed to in writing, software |
| 14 | distributed under the License is distributed on an "AS IS" BASIS, |
| 15 | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 16 | See the License for the specific language governing permissions and |
| 17 | limitations under the License. |
| 18 | |
| 19 | */ |
| 20 | |
| 21 | package org.apache.derby.iapi.sql.dictionary; |
| 22 | |
| 23 | import org.apache.derby.iapi.error.StandardException; |
| 24 | import org.apache.derby.catalog.UUID; |
| 25 | |
| 26 | import org.apache.derby.iapi.reference.SQLState; |
| 27 | import org.apache.derby.iapi.services.sanity.SanityManager; |
| 28 | import org.apache.derby.iapi.sql.StatementType; |
| 29 | import org.apache.derby.iapi.services.io.StoredFormatIds; |
| 30 | import org.apache.derby.iapi.error.StandardException; |
| 31 | import org.apache.derby.iapi.sql.depend.DependencyManager; |
| 32 | import org.apache.derby.iapi.sql.depend.Dependent; |
| 33 | import org.apache.derby.iapi.sql.depend.Dependency; |
| 34 | import org.apache.derby.iapi.sql.depend.Provider; |
| 35 | import org.apache.derby.iapi.sql.conn.LanguageConnectionContext; |
| 36 | import org.apache.derby.iapi.services.sanity.SanityManager; |
| 37 | |
| 38 | /** |
| 39 | * A foreign key. |
| 40 | * |
| 41 | * @author Jamie |
| 42 | */ |
| 43 | public class ForeignKeyConstraintDescriptor extends KeyConstraintDescriptor |
| 44 | { |
| 45 | /** |
| 46 | interface to this descriptor |
| 47 | <ol> |
| 48 | <li>public ReferencedKeyConstraintDescriptor getReferencedConstraint() |
| 49 | throws StandardException; |
| 50 | <li>public UUID getReferencedConstraintId() |
| 51 | throws StandardException; |
| 52 | <li>public boolean isSelfReferencingFK() |
| 53 | throws StandardException; |
| 54 | <ol> |
| 55 | */ |
| 56 | |
| 57 | // Implementation |
| 58 | ReferencedKeyConstraintDescriptor referencedConstraintDescriptor; |
| 59 | UUID referencedConstraintId; |
| 60 | int raDeleteRule; |
| 61 | int raUpdateRule; |
| 62 | /** |
| 63 | * Constructor for a ForeignKeyConstraintDescriptor |
| 64 | * |
| 65 | * @param dataDictionary The data dictionary that this descriptor lives in |
| 66 | * @param table The descriptor of the table the constraint is on |
| 67 | * @param constraintName The name of the constraint. |
| 68 | * @param deferrable If the constraint can be deferred. |
| 69 | * @param initiallyDeferred If the constraint starts life deferred. |
| 70 | * @param fkColumns columns in the foreign key |
| 71 | * @param constraintId UUID of constraint |
| 72 | * @param indexId The UUID for the backing index |
| 73 | * @param schemaDesc The SchemaDescriptor for the constraint |
| 74 | * @param referencedConstraintDescriptor is referenced constraint descriptor |
| 75 | * @param isEnabled is the constraint enabled? |
| 76 | */ |
| 77 | protected ForeignKeyConstraintDescriptor( |
| 78 | DataDictionary dataDictionary, |
| 79 | TableDescriptor table, |
| 80 | String constraintName, |
| 81 | boolean deferrable, |
| 82 | boolean initiallyDeferred, |
| 83 | int[] fkColumns, |
| 84 | UUID constraintId, |
| 85 | UUID indexId, |
| 86 | SchemaDescriptor schemaDesc, |
| 87 | ReferencedKeyConstraintDescriptor referencedConstraintDescriptor, |
| 88 | boolean isEnabled, |
| 89 | int raDeleteRule, |
| 90 | int raUpdateRule |
| 91 | ) |
| 92 | { |
| 93 | super(dataDictionary, table, constraintName, deferrable, |
| 94 | initiallyDeferred, fkColumns, |
| 95 | constraintId, indexId, schemaDesc, isEnabled); |
| 96 | |
| 97 | this.referencedConstraintDescriptor = referencedConstraintDescriptor; |
| 98 | this.raDeleteRule = raDeleteRule; |
| 99 | this.raUpdateRule = raUpdateRule; |
| 100 | } |
| 101 | |
| 102 | /** |
| 103 | * Constructor for a ForeignKeyConstraintDescriptor |
| 104 | * |
| 105 | * @param dataDictionary The data dictionary that this descriptor lives in |
| 106 | * @param table The descriptor of the table the constraint is on |
| 107 | * @param constraintName The name of the constraint. |
| 108 | * @param deferrable If the constraint can be deferred. |
| 109 | * @param initiallyDeferred If the constraint starts life deferred. |
| 110 | * @param fkColumns columns in the foreign key |
| 111 | * @param constraintId UUID of constraint |
| 112 | * @param indexId The UUID for the backing index |
| 113 | * @param schemaDesc The SchemaDescriptor for the constraint |
| 114 | * @param referencedConstraintId is referenced constraint id |
| 115 | * @param isEnabled is the constraint enabled? |
| 116 | */ |
| 117 | ForeignKeyConstraintDescriptor( |
| 118 | DataDictionary dataDictionary, |
| 119 | TableDescriptor table, |
| 120 | String constraintName, |
| 121 | boolean deferrable, |
| 122 | boolean initiallyDeferred, |
| 123 | int[] fkColumns, |
| 124 | UUID constraintId, |
| 125 | UUID indexId, |
| 126 | SchemaDescriptor schemaDesc, |
| 127 | UUID referencedConstraintId, |
| 128 | boolean isEnabled, |
| 129 | int raDeleteRule, |
| 130 | int raUpdateRule |
| 131 | ) |
| 132 | { |
| 133 | super(dataDictionary, table, constraintName, deferrable, |
| 134 | initiallyDeferred, fkColumns, |
| 135 | constraintId, indexId, schemaDesc, isEnabled); |
| 136 | this.referencedConstraintId = referencedConstraintId; |
| 137 | this.raDeleteRule = raDeleteRule; |
| 138 | this.raUpdateRule = raUpdateRule; |
| 139 | |
| 140 | } |
| 141 | |
| 142 | /** |
| 143 | * Get the constraint that this FK references. Will |
| 144 | * return either a primary key or a unique key constriant. |
| 145 | * |
| 146 | * @return the constraint |
| 147 | * |
| 148 | * @exception StandardException on error |
| 149 | */ |
| 150 | public ReferencedKeyConstraintDescriptor getReferencedConstraint() |
| 151 | throws StandardException |
| 152 | { |
| 153 | if (referencedConstraintDescriptor != null) |
| 154 | { |
| 155 | return referencedConstraintDescriptor; |
| 156 | } |
| 157 | |
| 158 | if (referencedConstraintId == null) |
| 159 | { |
| 160 | getReferencedConstraintId(); |
| 161 | } |
| 162 | |
| 163 | TableDescriptor refTd = getDataDictionary().getConstraintTableDescriptor(referencedConstraintId); |
| 164 | |
| 165 | if (SanityManager.DEBUG) |
| 166 | { |
| 167 | if (refTd == null) |
| 168 | { |
| 169 | SanityManager.THROWASSERT("not able to find "+referencedConstraintId+ |
| 170 | " in SYS.SYSCONSTRAINTS"); |
| 171 | } |
| 172 | } |
| 173 | |
| 174 | ConstraintDescriptorList cdl = getDataDictionary().getConstraintDescriptors(refTd); |
| 175 | referencedConstraintDescriptor = (ReferencedKeyConstraintDescriptor) |
| 176 | cdl.getConstraintDescriptorById(referencedConstraintId); |
| 177 | |
| 178 | if (SanityManager.DEBUG) |
| 179 | { |
| 180 | if (referencedConstraintDescriptor == null) |
| 181 | { |
| 182 | SanityManager.THROWASSERT("not able to find " |
| 183 | +referencedConstraintDescriptor+ " off of table descriptor " |
| 184 | +refTd.getName()); |
| 185 | } |
| 186 | } |
| 187 | |
| 188 | return referencedConstraintDescriptor; |
| 189 | } |
| 190 | |
| 191 | |
| 192 | /** |
| 193 | * Get the constraint id for the constraint that this FK references. |
| 194 | * Will return either a primary key or a unique key constriant. |
| 195 | * |
| 196 | * @return the constraint id |
| 197 | * |
| 198 | * @exception StandardException on error |
| 199 | */ |
| 200 | public UUID getReferencedConstraintId() throws StandardException |
| 201 | { |
| 202 | if (referencedConstraintDescriptor != null) |
| 203 | { |
| 204 | return referencedConstraintDescriptor.getUUID(); |
| 205 | } |
| 206 | |
| 207 | SubKeyConstraintDescriptor subKey; |
| 208 | subKey = getDataDictionary().getSubKeyConstraint(constraintId, |
| 209 | DataDictionary.FOREIGNKEY_CONSTRAINT); |
| 210 | if (SanityManager.DEBUG) |
| 211 | { |
| 212 | if (subKey == null) |
| 213 | { |
| 214 | SanityManager.THROWASSERT("not able to find "+constraintName+ |
| 215 | " in SYS.SYSFOREIGNKEYS"); |
| 216 | } |
| 217 | } |
| 218 | referencedConstraintId = subKey.getKeyConstraintId(); |
| 219 | return referencedConstraintId; |
| 220 | } |
| 221 | |
| 222 | /** |
| 223 | * Gets an identifier telling what type of descriptor it is |
| 224 | * (UNIQUE, PRIMARY KEY, FOREIGN KEY, CHECK). |
| 225 | * |
| 226 | * @return An identifier telling what type of descriptor it is |
| 227 | * (UNIQUE, PRIMARY KEY, FOREIGN KEY, CHECK). |
| 228 | */ |
| 229 | public int getConstraintType() |
| 230 | { |
| 231 | return DataDictionary.FOREIGNKEY_CONSTRAINT; |
| 232 | } |
| 233 | |
| 234 | /** |
| 235 | * Does this constraint need to fire on this type of |
| 236 | * DML? True if insert or update and columns intersect |
| 237 | * |
| 238 | * @param stmtType the type of DML |
| 239 | * (StatementType.INSERT|StatementType.UPDATE|StatementType.DELETE) |
| 240 | * @param modifiedCols the columns modified, or null for all |
| 241 | * |
| 242 | * @return true/false |
| 243 | */ |
| 244 | public boolean needsToFire(int stmtType, int[] modifiedCols) |
| 245 | { |
| 246 | /* |
| 247 | ** If we are disabled, we never fire |
| 248 | */ |
| 249 | if (!isEnabled) |
| 250 | { |
| 251 | return false; |
| 252 | } |
| 253 | |
| 254 | if (stmtType == StatementType.DELETE) |
| 255 | { |
| 256 | return false; |
| 257 | } |
| 258 | if (stmtType == StatementType.INSERT) |
| 259 | { |
| 260 | return true; |
| 261 | } |
| 262 | |
| 263 | // if update, only relevant if columns intersect |
| 264 | return doColumnsIntersect(modifiedCols, getReferencedColumns()); |
| 265 | } |
| 266 | |
| 267 | /** |
| 268 | * Am I a self-referencing FK? True if my referenced |
| 269 | * constraint is on the same table as me. |
| 270 | * |
| 271 | * @return true/false |
| 272 | * |
| 273 | * @exception StandardException on error |
| 274 | */ |
| 275 | public boolean isSelfReferencingFK() |
| 276 | throws StandardException |
| 277 | { |
| 278 | ReferencedKeyConstraintDescriptor refcd = getReferencedConstraint(); |
| 279 | return (refcd.getTableId().equals(getTableId())); |
| 280 | } |
| 281 | |
| 282 | /** |
| 283 | * Gets a referential action rule on a DELETE |
| 284 | * @return referential rule defined by the user during foreign key creattion |
| 285 | * for a delete (like CASCDE , RESTRICT ..etc) |
| 286 | */ |
| 287 | public int getRaDeleteRule() |
| 288 | { |
| 289 | return raDeleteRule; |
| 290 | } |
| 291 | |
| 292 | |
| 293 | /** |
| 294 | * Gets a referential action rule on a UPDATE |
| 295 | * @return referential rule defined by the user during foreign key creattion |
| 296 | * for an UPDATE (like CASCDE , RESTRICT ..etc) |
| 297 | */ |
| 298 | public int getRaUpdateRule() |
| 299 | { |
| 300 | return raUpdateRule; |
| 301 | } |
| 302 | |
| 303 | } |
| 304 | |
| 305 | |
| 306 | |
| 307 | |
| 308 | |
| 309 | |
| 310 | |