01: /*
02:
03: Derby - Class org.apache.derby.iapi.sql.execute.TupleFilter
04:
05: Licensed to the Apache Software Foundation (ASF) under one or more
06: contributor license agreements. See the NOTICE file distributed with
07: this work for additional information regarding copyright ownership.
08: The ASF licenses this file to you under the Apache License, Version 2.0
09: (the "License"); you may not use this file except in compliance with
10: the License. You may obtain a copy of the License at
11:
12: http://www.apache.org/licenses/LICENSE-2.0
13:
14: Unless required by applicable law or agreed to in writing, software
15: distributed under the License is distributed on an "AS IS" BASIS,
16: WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
17: See the License for the specific language governing permissions and
18: limitations under the License.
19:
20: */
21:
22: package org.apache.derby.iapi.sql.execute;
23:
24: import org.apache.derby.iapi.types.BooleanDataValue;
25:
26: import org.apache.derby.iapi.error.StandardException;
27:
28: /**
29: * A TupleFilter is used to qualify rows from a tuple stream.
30: *
31: * @author Rick
32: */
33: public interface TupleFilter {
34: /**
35: * Initialize a Filter with a vector of parameters.
36: *
37: * @param parameters An ExecRow of parameter values
38: *
39: * @exception StandardException Thrown on error
40: */
41: public void init(ExecRow parameters) throws StandardException;
42:
43: /**
44: * Pump a row through the Filter.
45: *
46: * @param currentRow Column values to plug into restriction
47: *
48: * @return True if the row qualifies. False otherwise.
49: *
50: * @exception StandardException Thrown on error
51: */
52: public BooleanDataValue execute(ExecRow currentRow)
53: throws StandardException;
54: }
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