| 1 | /* |
| 2 | |
| 3 | Derby - Class org.apache.derby.iapi.sql.dictionary.ColumnDescriptorList |
| 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.iapi.services.sanity.SanityManager; |
| 25 | |
| 26 | import org.apache.derby.catalog.UUID; |
| 27 | |
| 28 | import org.apache.derby.iapi.error.StandardException; |
| 29 | import org.apache.derby.iapi.services.sanity.SanityManager; |
| 30 | |
| 31 | import java.util.ArrayList; |
| 32 | import java.util.Iterator; |
| 33 | |
| 34 | /** |
| 35 | * This represents a list of column descriptors. |
| 36 | */ |
| 37 | |
| 38 | public class ColumnDescriptorList extends ArrayList |
| 39 | { |
| 40 | /** |
| 41 | * Add the column. Currently, the table id is ignored. |
| 42 | * |
| 43 | * @param tableID the table id (ignored) |
| 44 | * @param column the column to add |
| 45 | */ |
| 46 | public void add(UUID tableID, ColumnDescriptor column) |
| 47 | { |
| 48 | /* |
| 49 | ** RESOLVE: The interface includes tableID because presumably |
| 50 | ** the primary key for the columns table will be tableID + |
| 51 | ** columnID (or possibly tableID + column name - both column |
| 52 | ** name and ID must be unique within a table). However, the |
| 53 | ** ColumnDescriptor contains a reference to a tableID, so it |
| 54 | ** seems like we don't need the parameter here. I am going |
| 55 | ** to leave it here just in case we decide we need it later. |
| 56 | */ |
| 57 | add(column); |
| 58 | } |
| 59 | |
| 60 | /** |
| 61 | * Get the column descriptor |
| 62 | * |
| 63 | * @param tableID the table id (ignored) |
| 64 | * @param columnName the column get |
| 65 | * |
| 66 | * @return the column descriptor if found |
| 67 | */ |
| 68 | public ColumnDescriptor getColumnDescriptor(UUID tableID, |
| 69 | String columnName) |
| 70 | { |
| 71 | ColumnDescriptor returnValue = null; |
| 72 | |
| 73 | for (Iterator iterator = iterator(); iterator.hasNext(); ) |
| 74 | { |
| 75 | ColumnDescriptor columnDescriptor = (ColumnDescriptor) iterator.next(); |
| 76 | |
| 77 | if ( columnName.equals( columnDescriptor.getColumnName() ) && |
| 78 | tableID.equals( columnDescriptor.getReferencingUUID() ) ) |
| 79 | { |
| 80 | returnValue = columnDescriptor; |
| 81 | break; |
| 82 | } |
| 83 | } |
| 84 | |
| 85 | return returnValue; |
| 86 | } |
| 87 | |
| 88 | /** |
| 89 | * Get the column descriptor |
| 90 | * |
| 91 | * @param tableID the table id (ignored) |
| 92 | * @param columnID the column id |
| 93 | * |
| 94 | * @return the column descriptor if found |
| 95 | */ |
| 96 | public ColumnDescriptor getColumnDescriptor(UUID tableID, int columnID) |
| 97 | { |
| 98 | ColumnDescriptor returnValue = null; |
| 99 | |
| 100 | for (Iterator iterator = iterator(); iterator.hasNext(); ) |
| 101 | { |
| 102 | ColumnDescriptor columnDescriptor = (ColumnDescriptor) iterator.next(); |
| 103 | if ( ( columnID == columnDescriptor.getPosition() ) && |
| 104 | tableID.equals( columnDescriptor.getReferencingUUID() ) ) |
| 105 | { |
| 106 | returnValue = columnDescriptor; |
| 107 | break; |
| 108 | } |
| 109 | } |
| 110 | |
| 111 | return returnValue; |
| 112 | } |
| 113 | |
| 114 | /** |
| 115 | * Return the nth (0-based) element in the list. |
| 116 | * |
| 117 | * @param n Which element to return. |
| 118 | * |
| 119 | * @return The nth element in the list. |
| 120 | */ |
| 121 | public ColumnDescriptor elementAt(int n) |
| 122 | { |
| 123 | return (ColumnDescriptor) get(n); |
| 124 | } |
| 125 | |
| 126 | /** |
| 127 | * Get an array of strings for all the columns |
| 128 | * in this CDL. |
| 129 | * |
| 130 | * @return the array of strings |
| 131 | */ |
| 132 | public String[] getColumnNames() |
| 133 | { |
| 134 | String strings[] = new String[size()]; |
| 135 | |
| 136 | int size = size(); |
| 137 | |
| 138 | for (int index = 0; index < size; index++) |
| 139 | { |
| 140 | ColumnDescriptor columnDescriptor = elementAt(index); |
| 141 | strings[index] = columnDescriptor.getColumnName(); |
| 142 | } |
| 143 | return strings; |
| 144 | } |
| 145 | } |