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1
56 package org.objectstyle.cayenne.dba.mysql;
57
58 import java.sql.Connection  ;
59 import java.sql.ResultSet ;
60 import java.sql.SQLException ;
61 import java.sql.Statement ;
62 import java.util.Collections ;
63
64 import org.objectstyle.cayenne.access.DataNode;
65 import org.objectstyle.cayenne.access.QueryLogger;
66 import org.objectstyle.cayenne.dba.JdbcPkGenerator;
67 import org.objectstyle.cayenne.map.DbEntity;
68
69
72 public class MySQLPkGenerator extends JdbcPkGenerator {
73
77 protected int pkFromDatabase(DataNode node, DbEntity ent)
78 throws Exception {
79
80
84 SQLException exception = null;
86 int pk = -1;
87
88 Connection con = node.getDataSource().getConnection();
89 try {
90 Statement st = con.createStatement();
91
92 try {
93 pk = getPrimaryKey(st, ent.getName());
94 } catch (SQLException pkEx) {
95 exception = processSQLException(pkEx, exception);
96 } finally {
97 try {
100 String unlockString = "UNLOCK TABLES";
101 QueryLogger.logQuery(QueryLogger.DEFAULT_LOG_LEVEL, unlockString, Collections.EMPTY_LIST);
102 st.execute(unlockString);
103 } catch (SQLException unlockEx) {
104 exception = processSQLException(unlockEx, exception);
105 } finally {
106 try {
108 st.close();
109 } catch (SQLException stClosingEx) {
110 }
112 }
113 }
114 } catch (SQLException otherEx) {
115 exception = processSQLException(otherEx, exception);
116 } finally {
117 try {
118 con.close();
119 } catch (SQLException closingEx) {
120 }
122 }
123
124 if (exception != null) {
126 throw exception;
127 }
128
129 return pk;
130 }
131
132
136 protected SQLException processSQLException(SQLException exception, SQLException parent) {
137 if(parent == null) {
138 return exception;
139 }
140
141 parent.setNextException(exception);
142 return parent;
143 }
144
145 protected String pkTableCreateString() {
146 StringBuffer buf = new StringBuffer ();
147 buf
148 .append("CREATE TABLE AUTO_PK_SUPPORT (")
149 .append(" TABLE_NAME CHAR(100) NOT NULL,")
150 .append(" NEXT_ID INTEGER NOT NULL, UNIQUE (TABLE_NAME)")
151 .append(")");
152
153 return buf.toString();
154 }
155
156 protected int getPrimaryKey(Statement statement, String entityName)
157 throws SQLException {
158 String lockString = "LOCK TABLES AUTO_PK_SUPPORT WRITE";
160 QueryLogger.logQuery(QueryLogger.DEFAULT_LOG_LEVEL, lockString, Collections.EMPTY_LIST);
161 statement.execute(lockString);
162
163 int pk = -1;
165
166 String selectString = super.pkSelectString(entityName);
167 QueryLogger.logQuery(QueryLogger.DEFAULT_LOG_LEVEL, selectString, Collections.EMPTY_LIST);
168 ResultSet rs = statement.executeQuery(selectString);
169 try {
170 if(!rs.next()) {
171 throw new SQLException ("No rows for '" + entityName + "'");
172 }
173
174 pk = rs.getInt(1);
175
176 if(rs.next()) {
177 throw new SQLException ("More than one row for '" + entityName + "'");
178 }
179 } finally {
180 try {
181 rs.close();
182 } catch (Exception ex) {
183 }
185 }
186
187 String updateString = super.pkUpdateString(entityName) + " AND NEXT_ID = " + pk;
189 QueryLogger.logQuery(QueryLogger.DEFAULT_LOG_LEVEL, updateString, Collections.EMPTY_LIST);
190 int updated = statement.executeUpdate(updateString);
191 if(updated != 1) {
193 throw new SQLException ("Error updating PK count '" + entityName + "': " + updated);
194 }
195
196 return pk;
197 }
198 } |
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