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Java > Open Source Codes > org > apache > cayenne > dba > postgres > PostgresQualifierTranslator


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19
20 package org.apache.cayenne.dba.postgres;
21
22 import org.apache.cayenne.access.trans.QueryAssembler;
23 import org.apache.cayenne.access.trans.TrimmingQualifierTranslator;
24 import org.apache.cayenne.exp.Expression;
25
26 /**
27  * Uses Postgres extensions to optimize various translations.
28  *
29  * @author Andrus Adamchik
30  * @since 1.1
31  */
32 public class PostgresQualifierTranslator extends TrimmingQualifierTranslator {
33
34     public PostgresQualifierTranslator(QueryAssembler queryAssembler) {
35         super(queryAssembler, "RTRIM");
36     }
37
38     public void startNode(Expression node, Expression parentNode) {
39
40         if (node.getOperandCount() == 2) {
41             // binary nodes are the only ones that currently require this
42 detectObjectMatch(node);
43
44             if (parenthesisNeeded(node, parentNode)) {
45                 qualBuf.append('(');
46             }
47
48             // super implementation has special handling
49 // of LIKE_IGNORE_CASE and NOT_LIKE_IGNORE_CASE
50 // Postgres uses ILIKE
51 // ...
52 }
53         else {
54             super.startNode(node, parentNode);
55         }
56     }
57
58     public void endNode(Expression node, Expression parentNode) {
59         if (node.getOperandCount() == 2) {
60             // check if we need to use objectMatchTranslator to finish building the expression
61 if (matchingObject) {
62                 appendObjectMatch();
63             }
64
65             if (parenthesisNeeded(node, parentNode))
66                 qualBuf.append(')');
67
68             // super implementation has special handling
69 // of LIKE_IGNORE_CASE and NOT_LIKE_IGNORE_CASE
70 // Postgres uses ILIKE
71 // ...
72 }
73         else {
74             super.endNode(node, parentNode);
75         }
76     }
77
78     public void finishedChild(Expression node, int childIndex, boolean hasMoreChildren) {
79         if (!hasMoreChildren) {
80             return;
81         }
82
83         // use ILIKE
84
85         switch (node.getType()) {
86
87             case Expression.LIKE_IGNORE_CASE :
88                 finishedChildNodeAppendExpression(node, " ILIKE ");
89                 break;
90             case Expression.NOT_LIKE_IGNORE_CASE :
91                 finishedChildNodeAppendExpression(node, " NOT ILIKE ");
92                 break;
93             default :
94                 super.finishedChild(node, childIndex, hasMoreChildren);
95         }
96     }
97
98     private void finishedChildNodeAppendExpression(Expression node, String JavaDoc operation) {
99         StringBuffer JavaDoc buf = (matchingObject) ? new StringBuffer JavaDoc() : qualBuf;
100         buf.append(operation);
101         if (matchingObject) {
102             objectMatchTranslator.setOperation(buf.toString());
103             objectMatchTranslator.setExpression(node);
104         }
105     }
106 }
107
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