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1
5 package org.h2.command.dml;
6
7 import java.sql.SQLException  ;
8
9 import org.h2.command.Prepared;
10 import org.h2.engine.Right;
11 import org.h2.engine.Session;
12 import org.h2.expression.Expression;
13 import org.h2.message.Message;
14 import org.h2.result.Row;
15 import org.h2.store.UndoLogRecord;
16 import org.h2.table.Column;
17 import org.h2.table.PlanItem;
18 import org.h2.table.Table;
19 import org.h2.table.TableFilter;
20 import org.h2.util.ObjectArray;
21 import org.h2.util.StringUtils;
22 import org.h2.value.Value;
23
24
27 public class Update extends Prepared {
28
29 private Expression condition;
30 private TableFilter tableFilter;
31 private Expression[] expressions;
32
33 public Update(Session session) {
34 super(session);
35 }
36
37 public void setTableFilter(TableFilter tableFilter) {
38 this.tableFilter = tableFilter;
39 Table table = tableFilter.getTable();
40 expressions = new Expression[table.getColumns().length];
41 }
42
43 public void setCondition(Expression condition) {
44 this.condition = condition;
45 }
46
47 public void setAssignment(Column column, Expression expression)
48 throws SQLException {
49 int id = column.getColumnId();
50 if (expressions[id] != null) {
51 throw Message.getSQLException(Message.DUPLICATE_COLUMN_NAME_1, column
52 .getName());
53 }
54 expressions[id] = expression;
55 }
56
57 public int update() throws SQLException {
58 tableFilter.startQuery();
59 tableFilter.reset();
60 ObjectArray oldRows = new ObjectArray();
62 ObjectArray newRows = new ObjectArray();
63 Table table = tableFilter.getTable();
64 session.getUser().checkRight(table, Right.UPDATE);
65 table.fireBefore(session);
66 table.lock(session, true);
67 int columnCount = table.getColumns().length;
68 setCurrentRowNumber(0);
70 while (tableFilter.next()) {
71 checkCancelled();
72 setCurrentRowNumber(oldRows.size()+1);
73 if (condition == null || Boolean.TRUE.equals(condition.getBooleanValue(session))) {
74 Row oldRow = tableFilter.get();
75 oldRows.add(oldRow);
76 Row newRow = table.getTemplateRow();
77 for (int i = 0; i < columnCount; i++) {
78 Expression newExpr = expressions[i];
79 Value newValue;
80 if (newExpr == null) {
81 newValue = oldRow.getValue(i);
82 } else {
83 Column column = table.getColumn(i);
84 newValue = newExpr.getValue(session).convertTo(column.getType());
85 }
86 newRow.setValue(i, newValue);
87 }
88 table.validateConvertUpdateSequence(session, newRow);
89 newRows.add(newRow);
90 }
91 }
92 if(table.fireRow()) {
97 for (int i = 0; i < oldRows.size(); i++) {
98 checkCancelled();
99 Row o = (Row) oldRows.get(i);
100 Row n = (Row) newRows.get(i);
101 table.fireBeforeRow(session, o, n);
102 }
103 }
104 for (int i = 0; i < oldRows.size(); i++) {
106 checkCancelled();
107 Row o = (Row) oldRows.get(i);
108 table.removeRow(session, o);
109 session.log(new UndoLogRecord(table, UndoLogRecord.DELETE, o));
110 }
111 for (int i=0; i < newRows.size(); i++) {
113 checkCancelled();
114 Row n = (Row) newRows.get(i);
115 table.addRow(session, n);
116 session.log(new UndoLogRecord(table, UndoLogRecord.INSERT, n));
117 }
118 if(table.fireRow()) {
119 for (int i=0; i < newRows.size(); i++) {
120 checkCancelled();
121 Row n = (Row) newRows.get(i);
122 Row o = (Row) oldRows.get(i);
123 table.fireAfterRow(session, o, n);
124 }
125 }
126 table.fireAfter(session);
127 return newRows.size();
128 }
129
130 public String getPlan() {
131 StringBuffer buff = new StringBuffer ();
132 buff.append("UPDATE ");
133 buff.append(tableFilter.getPlanSQL(false));
134 buff.append("\nSET ");
135 Table table = tableFilter.getTable();
136 int columnCount = table.getColumns().length;
137 for (int i = 0, j = 0; i < columnCount; i++) {
138 Expression newExpr = expressions[i];
139 if (newExpr != null) {
140 if(j>0) {
141 buff.append(",\n");
142 }
143 j++;
144 Column column = table.getColumn(i);
145 buff.append(column.getName());
146 buff.append(" = ");
147 buff.append(StringUtils.unEnclose(newExpr.getSQL()));
148 }
149 }
150 if(condition != null) {
151 buff.append("\nWHERE " + StringUtils.unEnclose(condition.getSQL()));
152 }
153 return buff.toString();
154 }
155
156 public void prepare() throws SQLException {
157 if (condition != null) {
158 condition.mapColumns(tableFilter, 0);
159 condition = condition.optimize(session);
160 condition.createIndexConditions(tableFilter);
161 }
162 for (int i = 0; i < expressions.length; i++) {
163 Expression expr = expressions[i];
164 if (expr != null) {
165 expr.mapColumns(tableFilter, 0);
166 expressions[i] = expr.optimize(session);
167 }
168 }
169 PlanItem item = tableFilter.getBestPlanItem(session);
170 tableFilter.setPlanItem(item);
171 tableFilter.prepare();
172 }
173
174 public boolean isTransactional() {
175 return true;
176 }
177
178 }
179 |
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