| 1 | /* ============================================================= |
| 2 | * SmallSQL : a free Java DBMS library for the Java(tm) platform |
| 3 | * ============================================================= |
| 4 | * |
| 5 | * (C) Copyright 2004-2006, by Volker Berlin. |
| 6 | * |
| 7 | * Project Info: http://www.smallsql.de/ |
| 8 | * |
| 9 | * This library is free software; you can redistribute it and/or modify it |
| 10 | * under the terms of the GNU Lesser General Public License as published by |
| 11 | * the Free Software Foundation; either version 2.1 of the License, or |
| 12 | * (at your option) any later version. |
| 13 | * |
| 14 | * This library is distributed in the hope that it will be useful, but |
| 15 | * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY |
| 16 | * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public |
| 17 | * License for more details. |
| 18 | * |
| 19 | * You should have received a copy of the GNU Lesser General Public |
| 20 | * License along with this library; if not, write to the Free Software |
| 21 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, |
| 22 | * USA. |
| 23 | * |
| 24 | * [Java is a trademark or registered trademark of Sun Microsystems, Inc. |
| 25 | * in the United States and other countries.] |
| 26 | * |
| 27 | * --------------- |
| 28 | * ExpressionFunctionCase.java |
| 29 | * --------------- |
| 30 | * Author: Volker Berlin |
| 31 | * |
| 32 | * Created on 29.06.2004 |
| 33 | */ |
| 34 | package smallsql.database; |
| 35 | |
| 36 | |
| 37 | /** |
| 38 | * @author Volker Berlin |
| 39 | */ |
| 40 | final class ExpressionFunctionCase extends Expression/*Function*/ { |
| 41 | |
| 42 | /** |
| 43 | * @param type |
| 44 | */ |
| 45 | ExpressionFunctionCase() { |
| 46 | super(FUNCTION); |
| 47 | } |
| 48 | |
| 49 | |
| 50 | private final Expressions cases = new Expressions(); |
| 51 | private final Expressions results = new Expressions(); |
| 52 | private Expression elseResult = ExpressionValue.NULL; |
| 53 | private int dataType = -1; |
| 54 | |
| 55 | |
| 56 | final void addCase(Expression condition, Expression result){ |
| 57 | cases.add(condition); |
| 58 | results.add(result); |
| 59 | } |
| 60 | |
| 61 | |
| 62 | final void setElseResult(Expression expr){ |
| 63 | elseResult = expr; |
| 64 | } |
| 65 | |
| 66 | |
| 67 | /** |
| 68 | * The structur is finish |
| 69 | */ |
| 70 | final void setEnd(){ |
| 71 | Expression[] params = new Expression[cases.size()*2 + (elseResult!=null ? 1 : 0)]; |
| 72 | int i=0; |
| 73 | for(int p=0; p<cases.size(); p++){ |
| 74 | params[i++] = cases .get( p ); |
| 75 | params[i++] = results.get( p ) ; |
| 76 | } |
| 77 | if(i<params.length) |
| 78 | params[i] = elseResult; |
| 79 | super.setParams(params); |
| 80 | } |
| 81 | |
| 82 | final void setParams( Expression[] params ){ |
| 83 | super.setParams(params); |
| 84 | int i = 0; |
| 85 | for(int p=0; p<cases.size(); p++){ |
| 86 | cases .set( p, params[i++]); |
| 87 | results.set( p, params[i++]); |
| 88 | } |
| 89 | if(i<params.length) |
| 90 | elseResult = params[i]; |
| 91 | } |
| 92 | |
| 93 | |
| 94 | void setParamAt( Expression param, int idx){ |
| 95 | super.setParamAt( param, idx ); |
| 96 | int p = idx / 2; |
| 97 | if(p>=cases.size()){ |
| 98 | elseResult = param; |
| 99 | return; |
| 100 | } |
| 101 | if(idx % 2 > 0){ |
| 102 | results.set( p, param ); |
| 103 | }else{ |
| 104 | cases.set( p, param ); |
| 105 | } |
| 106 | } |
| 107 | |
| 108 | |
| 109 | //================================ |
| 110 | // Methods of the interface |
| 111 | //================================ |
| 112 | |
| 113 | |
| 114 | final int getFunction() { |
| 115 | return SQLTokenizer.CASE; |
| 116 | } |
| 117 | |
| 118 | |
| 119 | final boolean isNull() throws Exception { |
| 120 | return getResult().isNull(); |
| 121 | } |
| 122 | |
| 123 | |
| 124 | final boolean getBoolean() throws Exception { |
| 125 | return getResult().getBoolean(); |
| 126 | } |
| 127 | |
| 128 | |
| 129 | final int getInt() throws Exception { |
| 130 | return getResult().getInt(); |
| 131 | } |
| 132 | |
| 133 | |
| 134 | final long getLong() throws Exception { |
| 135 | return getResult().getLong(); |
| 136 | } |
| 137 | |
| 138 | |
| 139 | final float getFloat() throws Exception { |
| 140 | return getResult().getFloat(); |
| 141 | } |
| 142 | |
| 143 | |
| 144 | final double getDouble() throws Exception { |
| 145 | return getResult().getDouble(); |
| 146 | } |
| 147 | |
| 148 | |
| 149 | final long getMoney() throws Exception { |
| 150 | return getResult().getMoney(); |
| 151 | } |
| 152 | |
| 153 | |
| 154 | final MutableNumeric getNumeric() throws Exception { |
| 155 | return getResult().getNumeric(); |
| 156 | } |
| 157 | |
| 158 | |
| 159 | final Object getObject() throws Exception { |
| 160 | return getResult().getObject(); |
| 161 | } |
| 162 | |
| 163 | |
| 164 | final String getString() throws Exception { |
| 165 | return getResult().getString(); |
| 166 | } |
| 167 | |
| 168 | |
| 169 | final byte[] getBytes() throws Exception{ |
| 170 | return getResult().getBytes(); |
| 171 | } |
| 172 | |
| 173 | |
| 174 | final int getDataType() { |
| 175 | if(dataType < 0){ |
| 176 | dataType = elseResult.getDataType(); |
| 177 | for(int i=0; i<results.size(); i++){ |
| 178 | dataType = ExpressionArithmetic.getDataType(dataType, results.get(i).getDataType()); |
| 179 | } |
| 180 | } |
| 181 | return dataType; |
| 182 | } |
| 183 | |
| 184 | |
| 185 | final int getPrecision(){ |
| 186 | int precision = 0; |
| 187 | for(int i=results.size()-1; i>=0; i--){ |
| 188 | precision = Math.max(precision, results.get(i).getPrecision()); |
| 189 | } |
| 190 | return precision; |
| 191 | } |
| 192 | |
| 193 | |
| 194 | final int getScale(){ |
| 195 | int precision = 0; |
| 196 | for(int i=results.size()-1; i>=0; i--){ |
| 197 | precision = Math.max(precision, results.get(i).getScale()); |
| 198 | } |
| 199 | return precision; |
| 200 | } |
| 201 | |
| 202 | |
| 203 | //================================ |
| 204 | // private helper functions |
| 205 | //================================ |
| 206 | |
| 207 | |
| 208 | final private Expression getResult() throws Exception{ |
| 209 | for(int i=0; i<cases.size(); i++){ |
| 210 | if(cases.get(i).getBoolean()) return results.get(i); |
| 211 | } |
| 212 | return elseResult; |
| 213 | } |
| 214 | |
| 215 | } |