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1
5 package org.h2.constraint;
6
7 import java.sql.SQLException  ;
8
9 import org.h2.engine.Session;
10 import org.h2.expression.Expression;
11 import org.h2.index.Index;
12 import org.h2.message.Message;
13 import org.h2.result.Row;
14 import org.h2.schema.Schema;
15 import org.h2.table.Column;
16 import org.h2.table.Table;
17 import org.h2.table.TableFilter;
18 import org.h2.util.StringUtils;
19
20
23
24 public class ConstraintCheck extends Constraint {
25
26 private TableFilter filter;
27 private Expression expr;
28
29 public ConstraintCheck(Schema schema, int id, String name, Table table) {
30 super(schema, id, name, table);
31 }
32
33 public String getConstraintType() {
34 return Constraint.CHECK;
35 }
36
37 public void setTableFilter(TableFilter filter) {
38 this.filter = filter;
39 }
40
41 public void setExpression(Expression expr) {
42 this.expr = expr;
43 }
44
45 public String getCreateSQLForCopy(Table table, String quotedName) {
46 StringBuffer buff = new StringBuffer ();
47 buff.append("ALTER TABLE ");
48 buff.append(table.getSQL());
49 buff.append(" ADD CONSTRAINT ");
50 buff.append(quotedName);
51 if(comment != null) {
52 buff.append(" COMMENT ");
53 buff.append(StringUtils.quoteStringSQL(comment));
54 }
55 buff.append(" CHECK");
56 buff.append(StringUtils.enclose(expr.getSQL()));
57 return buff.toString();
58 }
59
60 public String getShortDescription() {
61 StringBuffer buff = new StringBuffer ();
62 buff.append(getName());
63 buff.append(": ");
64 buff.append(expr.getSQL());
65 return buff.toString();
66 }
67
68 public String getCreateSQLWithoutIndexes() {
69 return getCreateSQL();
70 }
71
72 public String getCreateSQL() {
73 return getCreateSQLForCopy(table, getSQL());
74 }
75
76 public void removeChildrenAndResources(Session session) {
77 table.removeConstraint(this);
78 filter = null;
79 expr = null;
80 table = null;
81 invalidate();
82 }
83
84 public void checkRow(Session session, Table t, Row oldRow, Row newRow) throws SQLException {
85 if(newRow == null) {
86 return;
87 }
88 filter.set(newRow);
89 if(Boolean.FALSE.equals(expr.getValue(session).getBoolean())) {
91 throw Message.getSQLException(Message.CHECK_CONSTRAINT_VIOLATED_1, getShortDescription());
92 }
93 }
94
95 public boolean usesIndex(Index index) {
96 return false;
97 }
98
99 public boolean containsColumn(Column col) {
100 String s = col.getSQL();
102 String sql = getCreateSQL();
103 return sql.indexOf(s) >= 0;
104 }
105
106 public Expression getExpression() {
107 return expr;
108 }
109
110 public boolean isBefore() {
111 return true;
112 }
113
114 }
115 |
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