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1
22
23 package org.xquark.extractor.algebra;
24
25 import java.math.BigDecimal  ;
26 import java.sql.*;
27
28 import org.xquark.extractor.common.Debug;
29 import org.xquark.extractor.common.SqlWrapperException;
30 import org.xquark.extractor.sql.AbstractGenSqlVisitor;
31 import org.xquark.extractor.sql.SqlExpression;
32
33 public class PreEvaluationVisitor extends DefaultCompleteVisitor {
34
35 private static final String RCSRevision = "$Revision: 1.5 $";
36 private static final String RCSName = "$Name: $";
37
38
39 AbstractGenSqlVisitor _genSqlVisitor = null;
40 Statement _jdbcStatement = null;
41
42 public PreEvaluationVisitor() {
43 }
44
45 public PreEvaluationVisitor(AbstractGenSqlVisitor genSqlVisitor, Statement jdbcStatement) {
46 setGenSqlVisitor(genSqlVisitor);
47 setJdbcStatement(jdbcStatement);
48 }
49
50 public void setGenSqlVisitor(AbstractGenSqlVisitor genSqlVisitor) {
51 _genSqlVisitor = genSqlVisitor;
52 }
53
54 public void setJdbcStatement(Statement jdbcStatement) {
55 _jdbcStatement = jdbcStatement;
56 }
57
58 public void visit(TempValue arg) throws SqlWrapperException {
59 super.visit(arg);
60
61 if (null == arg.getValue()) {
62
63 try {
64 Expression subTree = arg.getOperand();
65 SqlTypeAtom sqlType = (SqlTypeAtom)subTree.getType();
66
67 _genSqlVisitor.reinit();
68 SqlExpression sql = subTree.accept(_genSqlVisitor);
69 ResultSet sqlResultSet = sql.Execute(_jdbcStatement);
70
71 sqlResultSet.next();
72
73 Literal litValue = null;
74
75 Object value = sqlResultSet.getObject(1);
76 if (null == value) {
77 litValue = new LitNull();
78 }
79 else if (value instanceof Integer ) {
80 litValue = new LitInteger((Integer )value);
81 }
82 else if (value instanceof BigDecimal ) {
83 litValue = new LitDecimal((BigDecimal )value);
84 }
85 else if (value instanceof Float ) {
86 litValue = new LitFloat((Float )value);
87 }
88 else if (value instanceof Double ) {
89 litValue = new LitDouble((Double )value);
90 }
91 else if (value instanceof String ) {
92 litValue = new LitString((String )value);
93 }
94 else if (value instanceof Date) {
95 litValue = new LitDate((Date)value);
96 }
97 else {
98 Debug.nyi("creating a literal for " + value.getClass().getName());
99 }
100
101 arg.setValue(litValue);
102
103 sqlResultSet.close();
104 }
105 catch (SQLException ex) {
106 throw new SqlWrapperException(ex.getMessage(), ex);
107 }
108 }
109 }
110 }
111 |
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