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1 package com.quadcap.sql;
2
3
40
41 import java.io.Externalizable  ;
42 import java.io.IOException ;
43 import java.io.ObjectInput ;
44 import java.io.ObjectOutput ;
45
46 import java.sql.SQLException ;
47
48 import com.quadcap.sql.io.Extern;
49
50 import com.quadcap.util.Debug;
51
52
57 public class DeleteConstraint extends LogStep implements Externalizable {
58 transient Table table;
59
60 Constraint constraint;
61 String tableName = null;
62 boolean global = false;
63
64 public DeleteConstraint() {}
65
66 public DeleteConstraint(Session session,
67 Table table, Constraint constraint) {
68 this(session, table, constraint, false);
69 }
70
71 public DeleteConstraint(Session session, Table table,
72 Constraint constraint, boolean global) {
73 super(session);
74 this.table = table;
75 this.constraint = constraint;
76 this.global = global;
77 this.tableName = table.getName();
78 }
79
80 Table getTable(Database db) throws IOException , SQLException {
81 if (table == null) {
82 table = (Table)db.getRelation(tableName);
83 if (table == null) {
84 throw new SQLException ("No table: " + tableName);
85 }
86 }
87 return table;
88 }
89
90 public void redo(Session session) throws IOException , SQLException {
91 Database db = session.getDatabase();
92 getTable(db);
93 table.deleteConstraint(constraint.getName());
94 if (constraint.table == null) {
95 constraint.setTable(table);
96 }
97 constraint.delete(session);
98 db.updateRelation(table);
99 if (global || constraint.isGlobal()) {
100 db.deleteIndex(constraint.getName());
101 }
102 }
103
104 public void undo(Session session) throws IOException , SQLException {
105 Database db = session.getDatabase();
106 getTable(db);
107 table.addConstraint(constraint);
108 constraint.undoDelete(session);
109 db.updateRelation(table);
110 if (global || constraint.isGlobal()) {
111 db.addIndex(constraint.getName(), table.getName());
112 }
113 }
114
115 public void prepare(Session session) throws IOException , SQLException {
116 }
117
118 public static void deleteForeign(Session session, Constraint constraint)
119 throws SQLException , IOException
120 {
121 Database db = session.getDatabase();
122 if (constraint instanceof ImportedKeyConstraint) {
123 ImportedKeyConstraint ic = (ImportedKeyConstraint)constraint;
124 Table f = ic.getFTable(db);
125 ExportedKeyConstraint ec = ic.findExportedKeyConstraint(db);
126 if (ec != null) {
127 session.doStep(new DeleteConstraint(session, f, ec));
128 }
129 } else if (constraint instanceof ExportedKeyConstraint) {
130 ExportedKeyConstraint ec = (ExportedKeyConstraint)constraint;
131 Table f = ec.getFTable(db);
132 ImportedKeyConstraint ic = ec.getImportedKeyConstraint(db);
133 if (ic != null) {
134 session.doStep(new DeleteConstraint(session, f, ic));
135 }
136 }
137
138 }
139
140 public void readExternal(ObjectInput in)
141 throws IOException , ClassNotFoundException
142 {
143 super.readExternal(in);
144 this.constraint = (Constraint)in.readObject();
145 this.tableName = (String )in.readObject();
146 this.global = in.read() == 1;
147 }
148
149 public void writeExternal(ObjectOutput out) throws IOException {
150 super.writeExternal(out);
151 out.writeObject(constraint);
152 out.writeObject(tableName);
153 out.write(global ? 1 : 0);
154 }
155
156 public String toString() {
158 StringBuffer sb = new StringBuffer (super.toString());
159 sb.append(" DeleteConstraint(");
160 sb.append(tableName);
161 sb.append(',');
162 sb.append(constraint.toString());
163 return sb.toString();
164 }
165
167 static Extern extern;
168 public void setExtern(Extern extern) { DeleteConstraint.extern = extern; }
169 public Extern getExtern() { return extern; }
170 }
171 |
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