DeleteTranslator


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10   *    http://www.apache.org/licenses/LICENSE-2.0
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19  
20  package org.apache.cayenne.access.trans;
21  
22  import org.apache.cayenne.map.DbEntity;
23  import org.apache.cayenne.map.DbRelationship;
24  
25  /** Class implements default translation mechanism of org.apache.cayenne.query.DeleteQuery
26   *  objects to SQL DELETE statements.
27   *
28   *  @author Andrus Adamchik
29   */
30  public class DeleteTranslator extends QueryAssembler {
31  
32      public String   aliasForTable(DbEntity dbEnt) {
33          throw new RuntimeException  ("aliases not supported");
34      }
35  
36      public void dbRelationshipAdded(DbRelationship dbRel) {
37          throw new RuntimeException  ("db relationships not supported");
38      }
39  
40      /** Main method of DeleteTranslator class. Translates DeleteQuery
41       *  into a JDBC PreparedStatement
42       */
43      public String   createSqlString() throws Exception   {
44          StringBuffer   queryBuf = new StringBuffer  ("DELETE FROM ");
45  
46          // 1. append table name
47          DbEntity dbEnt = getRootDbEntity();
48          queryBuf.append(dbEnt.getFullyQualifiedName());
49  
50          // 2. build qualifier
51          String   qualifierStr =
52              adapter.getQualifierTranslator(this).doTranslation();
53          if (qualifierStr != null)
54              queryBuf.append(" WHERE ").append(qualifierStr);
55  
56          return queryBuf.toString();
57      }
58  }
59
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