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1
28
29 package com.caucho.db.sql;
30
31 import com.caucho.log.Log;
32 import com.caucho.util.L10N;
33
34 import java.sql.SQLException  ;
35 import java.util.ArrayList ;
36 import java.util.logging.Logger ;
37
38 public class SubSelectExpr extends Expr {
39 protected static final L10N L = new L10N(SubSelectExpr.class);
40 private static final Logger log = Log.open(SubSelectExpr.class);
41
42 private int _groupIndex;
43 private SelectQuery _subselect;
44
45 private Query _parentQuery;
46
47 SubSelectExpr(SelectQuery query)
48 {
49 _subselect = query;
50 }
51
52
55 public SelectQuery getSubSelect()
56 {
57 return _subselect;
58 }
59
60
63 protected Expr bind(Query query)
64 throws SQLException
65 {
66 if (_parentQuery != null)
67 return this;
68
69 _parentQuery = query;
70 _groupIndex = query.getDataFields();
71
72 query.setDataFields(_groupIndex + 1);
73
74 _subselect.bind();
75
76 return this;
77 }
78
79
82 public Class getType()
83 {
84 return _subselect.getType();
85 }
86
87 ArrayList <SubSelectParamExpr> getParamExprs()
88 {
89 return _subselect.getParamExprs();
90 }
91
92
95 public long subCost(ArrayList <FromItem> fromList)
96 {
97 ArrayList <SubSelectParamExpr> paramExprs = getParamExprs();
98
99 long cost = 10;
100
101 for (int i = 0; i < paramExprs.size(); i++)
102 cost += paramExprs.get(i).getExpr().cost(fromList);
103
104 return 2 * cost;
105 }
106
107
110 void evaluate(QueryContext context)
111 throws SQLException
112 {
113 QueryContext subcontext = QueryContext.allocate();
114
115 ArrayList <SubSelectParamExpr> paramExprs = getParamExprs();
116
117 for (int i = 0; i < paramExprs.size(); i++) {
118 paramExprs.get(i).eval(context, subcontext);
119 }
120
121 _subselect.execute(subcontext, context.getTransaction());
122
123 SelectResult result = subcontext.getResult();
124
125 Data data = context.getGroupData(_groupIndex);
126
127 if (result.next()) {
128 Class type = _subselect.getType();
129
130 if (long.class.equals(type))
131 data.setLong(result.getLong(0));
132 else
133 data.setString(result.getString(0));
134 }
135 else {
136 data.clear();
137 }
138
139 result.close();
140 QueryContext.free(subcontext);
141 }
142
143
150 public String evalString(QueryContext context)
151 throws SQLException
152 {
153 Data data = context.getGroupData(_groupIndex);
154
155 return data.getString();
156 }
157
158 public String toString()
159 {
160 return "SubSelectExpr[" + _subselect + "]";
161 }
162 }
163 |
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