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1
5 package org.h2.expression;
6
7 import java.sql.SQLException  ;
8
9 import org.h2.engine.Session;
10 import org.h2.table.Column;
11 import org.h2.table.ColumnResolver;
12 import org.h2.table.TableFilter;
13 import org.h2.util.StringUtils;
14 import org.h2.value.Value;
15
16
17
20 public abstract class Expression {
21
22 private boolean addedToFilter;
23
24 public abstract Value getValue(Session session) throws SQLException ;
25 public abstract int getType();
26 public abstract void mapColumns(ColumnResolver resolver, int level) throws SQLException ;
27 public abstract Expression optimize(Session session) throws SQLException ;
28 public abstract void setEvaluatable(TableFilter tableFilter, boolean b);
29 public abstract int getScale();
30 public abstract long getPrecision();
31 public abstract String getSQL();
32 public abstract void updateAggregate(Session session) throws SQLException ;
33 public abstract boolean isEverything(ExpressionVisitor visitor);
34 public abstract int getCost();
35
36 public final boolean isEverything(int expressionVisitorType) {
37 ExpressionVisitor visitor = ExpressionVisitor.get(expressionVisitorType);
38 return isEverything(visitor);
39 }
40
41 public boolean isConstant() {
42 return false;
43 }
44
45 public boolean isAutoIncrement() {
46 return false;
47 }
48
49 public Boolean getBooleanValue(Session session) throws SQLException {
50 return getValue(session).getBoolean();
52 }
53
54 public void createIndexConditions(TableFilter filter) throws SQLException {
55 }
57
58 public String getColumnName() {
59 return getAlias();
60 }
61
62 public String getSchemaName() {
63 return null;
64 }
65
66 public String getTableName() {
67 return null;
68 }
69
70 public int getNullable() {
71 return Column.NULLABLE_UNKNOWN;
72 }
73
74 public String getTableAlias() {
75 return null;
76 }
77
78 public String getAlias() {
79 return StringUtils.unEnclose(getSQL());
80 }
81
82 public boolean isWildcard() {
83 return false;
84 }
85
86 public Expression getNonAliasExpression() {
87 return this;
88 }
89
90 public void addFilterConditions(TableFilter filter, boolean outerJoin) {
91 if(!addedToFilter && !outerJoin && isEverything(ExpressionVisitor.EVALUATABLE)) {
92 filter.addFilterCondition(this, false);
93 addedToFilter = true;
94 }
95 }
96 }
97 |
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