MatchSimpleReferencingExecuter


1   package com.daffodilwoods.daffodildb.server.serversystem.dmlvalidation.constraintsystem;
2   
3   import com.daffodilwoods.daffodildb.server.datadictionarysystem.*;
4   import com.daffodilwoods.daffodildb.server.datasystem.utility.*;
5   import com.daffodilwoods.daffodildb.server.serversystem.*;
6   import com.daffodilwoods.daffodildb.server.sessionsystem.*;
7   import com.daffodilwoods.daffodildb.server.sql99.common.*;
8   import com.daffodilwoods.daffodildb.server.sql99.expression.booleanvalueexpression.*;
9   import com.daffodilwoods.daffodildb.utils.field.*;
10  import com.daffodilwoods.database.resource.*;
11  import com.daffodilwoods.database.utility.P;
12  import com.daffodilwoods.daffodildb.utils.comparator.SuperComparator;
13  
14  /**
15   * Objective of this class is to check rows in child table when constraint
16   * is specified with match option - SIMPLE
17   * In match SIMPLE - If any of the values of referencing table is NULL, then row matchs
18   * with corresponding record in referenced table.
19   */
20  
21  public class MatchSimpleReferencingExecuter extends ReferencingExecuter {
22  
23    booleanvalueexpression condition;
24  
25    /**
26     * Constructor - constructs an instance of foreign constraint exception
27     * with the given arguments.
28     * @param referencingcnst Value of the Referenced Constraint Descriptor
29     *  having the details of the referenced constraints
30     * @throws DException
31     */
32    public MatchSimpleReferencingExecuter( _ReferentialConstraint referencingcnst,SuperComparator[] superComp  ) throws DException{
33      super(superComp);
34      referencingConstraint = referencingcnst;
35      referencedColumns  = referencingcnst.getReferencedColumns() ;
36      referencingColumns = referencingcnst.getReferencingColumns() ;
37      condition = referencingcnst.getMatchingRowsBVE(true);
38      tableDetails = new TableDetails();
39      tableDetails.setTableName(new String  []{referencingConstraint.getReferencedTable().catalog,referencingConstraint.getReferencedTable().schema,referencingConstraint.getReferencedTable().name});
40    }
41  
42    /**
43     * This method fires the constraint with match option SIMPLE, when insert/update
44     * is performed on the table.This method returns if the child table has any of
45     * the referencing column values as NULL, else checks the record against parent table.
46     * throws an exception is mismatch is found.
47     * @param recordVersion instance of RecordVersion
48     * @param globalSess instance of _ServerSession
49     * @throws DException
50     */
51    public void checkReferencingConstraints( RecordVersion recordVersion , _ServerSession globalSess ) throws DException {
52      _Record record = recordVersion.getCurrentRecord();
53      if( iterator == null ) {
54         iterator = ((GlobalSession)globalSess).getIterator( referencingConstraint.getReferencedTable(), referencingConstraint.getReferencedColumns());
55      }
56      for (int i = 0; i < referencingColumns.length; i++) {
57         if(((FieldBase)record.getObject(referencingColumns[i])).getNull())
58             return;
59      }
60      checkReferentialConstraints(setParameterValues(record));
61    }
62  
63    public Object  [] setParameterValues( _Record record) throws DException {
64        Object  [] columnValues = new Object  [referencingColumns.length];
65        for( int i=0; i<referencingColumns.length ; i++ )
66            columnValues[ i ] = record.getObject( referencingColumns[i] );
67        return columnValues;
68    }
69  }
70
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