SQLite数据库操作

在实际开发中经常会用到数据库的操作，这里简单总结下，也可以直接拿来用。

DatabaseHelper.java

 1 package com.serial.db;
 2 
 3 import android.content.ContentValues;
 4 import android.content.Context;
 5 import android.database.sqlite.SQLiteDatabase;
 6 import android.database.sqlite.SQLiteDatabase.CursorFactory;
 7 import android.database.sqlite.SQLiteOpenHelper;
 8 
 9 public class DatabaseHelper extends SQLiteOpenHelper {
10 
11     private static final String DB_NAME = "check_data.db"; //数据库名称
12     private static final int version = 1; //数据库版本
13     public static final String TABLE_NAME = "mydata"; 
14     
15     public DatabaseHelper(Context context) {
16         super(context, DB_NAME, null, version);
17         
18     }
19  
20     @Override
21     public void onCreate(SQLiteDatabase db) {
22         String sql = "create table "+TABLE_NAME+"(username varchar(20) not null , password varchar(60) not null );";          
23         db.execSQL(sql);
24     }
25  
26     @Override
27     public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
28        
29  
30     }
31     
32      
33 }

DBUtils.java

 1 package com.serial.db;
 2 
 3 import android.content.ContentValues;
 4 import android.content.Context;
 5 import android.database.Cursor;
 6 import android.database.sqlite.SQLiteDatabase;
 7 
 8 public class DBUtils {
 9 
10     SQLiteDatabase db = null;
11     DatabaseHelper database = null;
12     
13     public DBUtils(Context context){
14         
15         database = new DatabaseHelper(context);
16         db = database.getReadableDatabase();
17         
18     }
19     
20     //插入数据方式，两种
21     public void insertContent(ContentValues cv){
22         
23         db.insert(DatabaseHelper.TABLE_NAME,null,cv);//执行插入操作
24     }
25     
26     public void insertCommon(String strSql){
27         
28         db.execSQL(strSql);//执行SQL语句
29     }
30     
31     //删除数据方式，两种
32     public void deleteArgs(String whereClause, String[] whereArgs){
33         
34         db.delete(DatabaseHelper.TABLE_NAME,whereClause,whereArgs);//执行删除
35     }
36     
37     public void deleteSql(String delSql){
38         
39         db.execSQL(delSql);//执行删除操作
40     }
41     
42     //修改数据的方式， 两种
43     public void changeContent(ContentValues cv, String whereClause, String[] whereArgs ){
44         
45         db.update(DatabaseHelper.TABLE_NAME,cv,whereClause,whereArgs);//执行修改
46     }
47     
48     public void changeCommon(String updateSql){
49         
50         db.execSQL(updateSql);//执行修改
51     }
52     
53     //查询方式，两种
54     public String searchCursor(){
55         String username = "-1", password = "-1";
56         Cursor c = db.query(DatabaseHelper.TABLE_NAME,null,null,null,null,null,null);//查询并获得游标
57         if(c.moveToFirst()){//判断游标是否为空
58             for(int i=0;i<c.getCount();i++){
59                 c.move(i);//移动到指定记录
60                 username = c.getString(c.getColumnIndex("username"));
61                 password = c.getString(c.getColumnIndex("password"));
62             }
63         }
64         
65         return username + "," + password;
66     }
67     
68     public String searchRawQuery(){
69         
70         String username = "-1", password = "-1";
71         Cursor cursor = db.rawQuery("select * from "+DatabaseHelper.TABLE_NAME+" where username=?",new String[]{"Jack Johnson"});
72         if(cursor.moveToFirst()) {
73             username = cursor.getString(cursor.getColumnIndex("username"));
74             password = cursor.getString(cursor.getColumnIndex("password"));
75         }
76         
77         return username + "-" + password;
78     }
79 }

参考：http://www.cnblogs.com/Excellent/archive/2011/11/19/2254888.html