tsRow


1   /*
2    *
3    * tsRow.java - Row object for tinySQL.
4    * 
5    * Copyright 1996, Brian C. Jepson
6    *                 (bjepson@ids.net)
7    * $Author: davis $
8    * $Date: 2004/12/18 21:25:20 $
9    * $Revision: 1.1 $
10   *
11   * This library is free software; you can redistribute it and/or
12   * modify it under the terms of the GNU Lesser General Public
13   * License as published by the Free Software Foundation; either
14   * version 2.1 of the License, or (at your option) any later version.
15   *
16   * This library is distributed in the hope that it will be useful,
17   * but WITHOUT ANY WARRANTY; without even the implied warranty of
18   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
19   * Lesser General Public License for more details.
20   *
21   * You should have received a copy of the GNU Lesser General Public
22   * License along with this library; if not, write to the Free Software
23   * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
24   *
25   */
26  
27  package com.sqlmagic.tinysql;
28  
29  import java.util.*;
30  import java.lang.*;
31  import java.io.*;
32  
33  /*
34   *
35   * tsRow - an extension to Hashtable to hold a given row.
36   *
37   */
38  class tsRow extends Hashtable implements Comparable   
39  {
40     Vector orderByColumns = (Vector)null;
41     boolean debug=false;
42    /**
43     *
44     * Given a column name, returns its value as a string.
45     *
46     * @param column the name of the column
47     *
48     */
49    public void setOrderBy(Vector inputColumns)
50    {
51       orderByColumns = inputColumns;
52    }
53    public String   columnAsString (String   column) {
54      return (String  ) get(column);
55    }
56  
57    /**
58     *
59     * Given a tsColumn object, returns its value as a String.
60     *
61     * @param column the tsColumn object
62     *
63     */
64     public String   columnAsString (tsColumn column)
65     {
66        String   outputString,valueString,functionName,argList,nextArg;
67        StringBuffer   functionBuffer;
68        FieldTokenizer ft1,ft2;
69  /*
70   *    Next try to retrieve as a group function, which will not have a
71   *    tablename prefix.
72   */
73        outputString = (String  )get(column.name);
74        if ( outputString != (String  )null ) return outputString;
75        ft1 = new FieldTokenizer(column.name,'(',false);
76        if ( ft1.countFields() == 2 )
77        {
78  /*
79   *       The column is a function.  If it is a group function, the value
80   *       will be stored in the record.  Otherwise, the function value
81   *       will be determined here by retrieving and processing all the
82   *       columns in the function arguments.
83   */
84           outputString = (String  )get(column.name);
85           if ( outputString != (String  )null ) return outputString;
86           functionName = ft1.getField(0);
87           argList = ft1.getField(1);
88           ft2 = new FieldTokenizer(argList,',',false);
89           functionBuffer = new StringBuffer  ();
90  /*
91   *       Function arguments must consist of table.column names or constants.
92   */
93           while ( ft2.hasMoreFields() )
94           {
95              nextArg = ft2.nextField();
96              valueString = (String  )get(nextArg);
97              if ( debug) System.out.println("Function " + functionName
98              + " argument " + nextArg + " has value " + valueString);
99  /*
100  *          If the valueString is null then it is a constant rather than
101  *          a database column.  Remove enclosing quotes.
102  */
103             if ( valueString == (String  )null ) 
104                valueString = UtilString.removeQuotes(nextArg);
105             else 
106                valueString = valueString.trim();
107             if ( functionName.equals("CONCAT") )
108                functionBuffer.append(valueString);
109          }
110          outputString = functionBuffer.toString();
111       } else if ( column.table == (String  )null )  {
112 /*
113  *       This is a constant.  Return the table name which will be equal to
114  *       the constant value.
115  */
116          outputString = UtilString.removeQuotes(column.name);
117       } else {
118 /*
119  *       Retrieve as a simple database column.
120  */ 
121          outputString = (String  )get(column.table + "." + column.name);
122       }
123       return outputString;
124    }
125    public int compareTo(Object   inputObj)
126    {
127       String   tableColumnName,thisString,inputString;
128       tsColumn columnObject;
129       tsRow inputRow;
130       int i,columnType;
131       double thisValue,inputValue;
132       if ( orderByColumns == (Vector)null ) return 0;
133       inputRow = (tsRow)inputObj;
134       for ( i = 0; i < orderByColumns.size(); i++ )
135       {
136          columnObject = (tsColumn)orderByColumns.elementAt(i);
137          tableColumnName = columnObject.name;
138          columnType = columnObject.type;
139          thisString = (String  )get(tableColumnName);
140          inputString = (String  )inputRow.get(tableColumnName);
141          if ( Utils.isCharColumn(columnType) | 
142               Utils.isDateColumn(columnType) )
143          {
144             if ( thisString == (String  )null | inputString == (String  )null )
145                continue;
146             if ( thisString.compareTo(inputString) != 0 )
147                return thisString.compareTo(inputString);
148          } else if ( Utils.isNumberColumn(columnType) ) {
149             thisValue = UtilString.doubleValue(thisString);
150             inputValue = UtilString.doubleValue(inputString);
151             if ( thisValue > inputValue ) return 1;
152             else if ( thisValue < inputValue ) return -1;
153          } else {
154             System.out.println("Cannot sort unknown type");
155          }
156       }
157       return 0;
158    }
159    public String   toString()
160    {
161       StringBuffer   outputBuffer = new StringBuffer  ();
162       String   columnName,columnValue;
163       Enumeration e;
164       for ( e = this.keys(); e.hasMoreElements(); )
165       {
166          columnName = (String  )e.nextElement();
167          columnValue = (String  )this.get(columnName);
168          outputBuffer.append(columnName + "=" + columnValue + " ");
169       }
170       return outputBuffer.toString();
171    }
172 }
173 
174
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