HA1CUr4F

1package dbclasstest;
2
3// Import all of the Java SQL classes 
4import java.sql.Connection;
5import java.sql.DriverManager;
6import java.sql.DatabaseMetaData;
7import java.sql.SQLException;
8import java.sql.Statement; 
9import java.sql.ResultSet;
10
11/**
12 * Allows easy creation and modification of an SQLite databasn by offering
13 * simple command and methods that can be called.
14 *
15 * @author      Dan 
16 * @version     %I%, %G%
17 * @since       1.0
18 */
19public class db
20{
21    private Connection con; 
22    private Statement stmt; 
23    private String dburl;
24
25    /**
26     * Creates a .db database file with the name that is passed in 'dbname' 
27     * 
28     * @param dbname    The string name of the database file, e.g. MyDatabase(.db)
29     */
30    public db ( String dbname )
31    {
32        try {
33            Class.forName( "org.sqlite.JDBC" );
34            this.dburl = "jdbc:sqlite:" + dbname + ".db";
35            
36            this.con = DriverManager.getConnection( this.dburl );
37            this.stmt = this.con.createStatement();
38            this.notify( "Connection established." );
39        } catch ( SQLException err ) {
40            err.printStackTrace();
41        } catch ( ClassNotFoundException err ) {
42            err.printStackTrace();
43        }
44    }
45    
46    /**
47     * Outputs the current driver's metadata. 
48     */
49    public void getInfo () 
50    {
51        try {
52            DatabaseMetaData dm = (DatabaseMetaData) this.con.getMetaData();
53
54            System.out.println( "Driver name: " + dm.getDriverName() );
55            System.out.println( "Driver version: " + dm.getDriverVersion() );
56            System.out.println( "Product name: " + dm.getDatabaseProductName() );
57            System.out.println( "Product version: " + dm.getDatabaseProductVersion() );
58        } catch ( SQLException err ) {
59            err.printStackTrace();
60        }
61    }
62    
63    /**
64     * Creates a table in the currently opened database.
65     *
66     * @param table_name    Name of the table to be created. 
67     * @param columns       An array of columns to be added to the table, the columns should be in order.Data types
68     *                      must also be defined in the string, e.g. "Names VARCHAR(60)". 
69     */
70    public void createTable( String table_name, String[] columns )
71    {
72        String query = "CREATE TABLE IF NOT EXISTS " + table_name + " ("; 
73        
74        for ( int x = 0; x < columns.length; x++ )
75        {
76            if ( x+1 == columns.length ) 
77            {
78                query = query + columns[x] + ")";
79            }
80            else
81            {
82                query = query + columns[x] + ", ";
83            }
84        }
85        
86        try { this.stmt.executeUpdate( query ); } catch ( SQLException err ) { err.printStackTrace(); }
87    }
88    
89    public void insert ( String table, String[][] elements )
90    {
91        
92    }
93    
94    public void update ( String query )     // TODO: allow custom update definitions 
95    {
96        try { this.stmt.executeUpdate( query ); } catch ( SQLException err ) { err.printStackTrace(); }
97    }
98    
99    public void query ( String query )      // TODO: allow custom query definitions 
100    {
101        try { 
102            ResultSet rs = this.stmt.executeQuery( query ); 
103            
104            while ( rs.next() )
105            {
106                System.out.print( rs.getInt( "ID" ) + "  " );
107                System.out.print( rs.getString( "FirstName" ) + "  " );
108                System.out.print( rs.getString( "LastName" ) + "\n" );
109            }
110        } catch ( SQLException err ) { err.printStackTrace(); }
111    }
112    
113    private boolean CheckPrimaryKeyIsValid ( String table, int key )
114    {
115        try {
116            ResultSet rs = this.stmt.executeQuery( "SELECT ID FROM " + table );
117            
118            while ( rs.next() ) 
119            { 
120                if ( rs.getInt( "ID" ) == key ) {  
121                    this.notify( "Key already exists in database." );
122                    return false;
123                } else return true; 
124            }
125        } catch ( SQLException err ) { err.printStackTrace(); }
126    }
127    
128    private void notify ( String message ) { System.out.println( "[SQLite]: " + message ); }
129}