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33 package smallsql.database;
34
35
36 abstract class Expression implements Cloneable  {
37
38 static final Expression NULL = new ExpressionValue( null, SQLTokenizer.NULL );
39
40 final private int type;
41 private String name; private String alias;
43
44
51 private Expression[] params;
52
53 Expression(int type){
54 this.type = type;
55 }
56
57 protected Object clone() throws CloneNotSupportedException {
58 return super.clone();
59 }
60
61 final String getName(){
62 return name;
63 }
64
65 final void setName(String name){
66 this.alias = this.name = name;
67 }
68
69 final String getAlias(){
70 return alias;
71 }
72
73 final void setAlias(String alias){
74 this.alias = alias;
75 }
76
77 void setParams( Expression[] params ){
78 this.params = params;
79 }
80
81
85 void setParamAt( Expression param, int idx){
86 params[idx] = param;
87 }
88
89 final Expression[] getParams(){ return params; }
90
91
94 public boolean equals(Object expr){
95 if(!(expr instanceof Expression)) return false;
96 if( ((Expression)expr).type == type){
97
98 Expression[] p1 = ((Expression)expr).params;
99 Expression[] p2 = params;
100 if(p1 != null && p2 != null){
101 if(p1 == null) return false;
102 for(int i=0; i<p1.length; i++){
103 if(!p2[i].equals(p1[i])) return false;
104 }
105 }
106 String name1 = ((Expression)expr).name;
107 String name2 = name;
108 if(name1 == name2) return true;
109 if(name1 == null) return false;
110 if(name1.equalsIgnoreCase(name2)) return true;
111 }
112 return false;
113 }
114
115
116 abstract boolean isNull() throws Exception ;
117
118 abstract boolean getBoolean() throws Exception ;
119
120 abstract int getInt() throws Exception ;
121
122 abstract long getLong() throws Exception ;
123
124 abstract float getFloat() throws Exception ;
125
126 abstract double getDouble() throws Exception ;
127
128 abstract long getMoney() throws Exception ;
129
130 abstract MutableNumeric getNumeric() throws Exception ;
131
132 abstract Object getObject() throws Exception ;
133
134 final Object getApiObject() throws Exception {
135 Object obj = getObject();
136 if(obj instanceof Mutable){
137 return ((Mutable)obj).getImmutableObject();
138 }
139 return obj;
140 }
141
142 abstract String getString() throws Exception ;
143
144 abstract byte[] getBytes() throws Exception ;
145
146 abstract int getDataType();
147
148 final int getType(){return type;}
149
150
155
156 String getTableName(){
157 return null;
158 }
159
160
161 int getPrecision(){
162 return SSResultSetMetaData.getDataTypePrecision( getDataType(), -1 );
163 }
164
165
166
167 int getScale(){
168 return getScale(getDataType());
169 }
170
171
172 final static int getScale(int dataType){
173 switch(dataType){
174 case SQLTokenizer.MONEY:
175 case SQLTokenizer.SMALLMONEY:
176 return 4;
177 case SQLTokenizer.TIMESTAMP:
178 return 9; case SQLTokenizer.NUMERIC:
180 case SQLTokenizer.DECIMAL:
181 return 38;
182 default: return 0;
183 }
184 }
185
186
187 int getDisplaySize(){
188 return SSResultSetMetaData.getDisplaySize(getDataType(), getPrecision(), getScale());
189 }
190
191 boolean isDefinitelyWritable(){
192 return false;
193 }
194
195 boolean isAutoIncrement(){
196 return false;
197 }
198
199 boolean isCaseSensitive(){
200 return false; }
202
203 boolean isNullable(){
204 return true; }
206
207
208 static final int VALUE = 1;
209 static final int NAME = 2;
210 static final int FUNCTION = 3;
211 static final int GROUP_BY = 11;
212 static final int COUNT = 12;
213 static final int SUM = 13;
214 static final int FIRST = 14;
215 static final int LAST = 15;
216 static final int MIN = 16;
217 static final int MAX = 17;
218 static final int GROUP_BEGIN= GROUP_BY;
219
220 } |
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