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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.message.Message;
11 import org.h2.schema.Sequence;
12 import org.h2.table.ColumnResolver;
13 import org.h2.table.TableFilter;
14 import org.h2.value.Value;
15 import org.h2.value.ValueInt;
16 import org.h2.value.ValueLong;
17
18 public class SequenceValue extends Expression {
19
20 private Sequence sequence;
21
22 public SequenceValue(Sequence sequence) {
23 this.sequence = sequence;
24 }
25
26 public Value getValue(Session session) throws SQLException {
27 long value = sequence.getNext();
28 session.setLastIdentity(value);
29 return ValueLong.get(value);
30 }
31
32 public int getType() {
33 return Value.LONG;
34 }
35
36 public void mapColumns(ColumnResolver resolver, int level) {
37 }
39
40 public void checkMapped() {
41 }
43
44 public Expression optimize(Session session) {
45 return this;
46 }
47
48 public void setEvaluatable(TableFilter tableFilter, boolean b) {
49 }
51
52 public int getScale() {
53 return 0;
54 }
55
56 public long getPrecision() {
57 return ValueInt.PRECISION;
58 }
59
60 public String getSQL() {
61 return "(NEXT VALUE FOR " + sequence.getSQL() +")";
62 }
63
64 public void updateAggregate(Session session) {
65 }
67
68 public boolean isEverything(ExpressionVisitor visitor) {
69 switch(visitor.type) {
70 case ExpressionVisitor.OPTIMIZABLE_MIN_MAX_COUNT_ALL:
71 return true;
72 case ExpressionVisitor.DETERMINISTIC:
73 case ExpressionVisitor.READONLY:
74 return false;
75 case ExpressionVisitor.INDEPENDENT:
76 return false;
77 case ExpressionVisitor.EVALUATABLE:
78 return true;
79 case ExpressionVisitor.SET_MAX_DATA_MODIFICATION_ID:
80 visitor.addDataModificationId(sequence.getModificationId());
81 return true;
82 default:
83 throw Message.getInternalError("type="+visitor.type);
84 }
85 }
86
87 public int getCost() {
88 return 1;
89 }
90
91 }
92 |
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