Android學習筆記之SQLite數據庫存儲

因為前面提到xml存儲更改文件很麻煩的緣故（ 見http://www.linuxidc.com/Linux/2012-01/50684.htm )，最終還是選擇了使用數據庫存儲

一試才覺十分的方便，速度也快

上源碼：

1. public class DBHelper extends SQLiteOpenHelper{
3. private final static String DATABASE_NAME="fanliao_db";
4. private final static int DATABASE_VERSION=1;
5. private final static String TABLE_NAME="fanliao_chat";
6. public final static String CHAT_ID="_id";
7. public final static String CHAT_Name="chatname";
8. public final static String CHAT_Info="chatinfo";
9. public final static String CHAT_Time="chattime";
12. public DBHelper(Context context)
13. {
14. super(context, DATABASE_NAME,null, DATABASE_VERSION);
15. }
19. @Override
20. public void onCreate(SQLiteDatabase db) {
21. //CREATE TABLE fanliao_chat( _id INTEGER PRIMARY KEY AUTOINCREMENT,
22. // chatname TEXT, chattime TEXT, chatinfo TEXT);
23. String sql="CREATE TABLE "+TABLE_NAME+"("+CHAT_ID+" INTEGER PRIMARY KEY AUTOINCREMENT,"
24. +CHAT_Name+" TEXT, "+CHAT_Time+" TEXT, "+CHAT_Info+" TEXT);";
25. db.execSQL(sql);
26. System.out.println(sql);
28. }
30. @Override
31. public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
32. String sql=" DROP TABLE IF EXISTS "+TABLE_NAME;
33. db.execSQL(sql);
34. onCreate(db);
35. System.out.println(sql);
36. }
38. public Cursor select()
39. {
40. SQLiteDatabase db=this.getReadableDatabase();
41. Cursor cursor=db.query(TABLE_NAME, null, null, null, null, null, " _id asc");
42. return cursor;
43. }
45. public long insert(String chatname, String chattime, String chatinfo)
46. {
47. SQLiteDatabase db=this.getWritableDatabase();
48. ContentValues cv=new ContentValues();
49. cv.put(CHAT_Name, chatname);
50. cv.put(CHAT_Time, chattime);
51. cv.put(CHAT_Info, chatinfo);
52. long row=db.insert(TABLE_NAME, null, cv);
53. return row;
54. }
56. public void delete(int id)
57. {
58. SQLiteDatabase db=this.getWritableDatabase();
59. String where=CHAT_ID+"=?";
60. String[] whereValue={Integer.toString(id)};
61. db.delete(TABLE_NAME, where, whereValue);
62. }
64. public void update(int id,String chatname,String chattime, String chatinfo)
65. {
66. SQLiteDatabase db=this.getWritableDatabase();
67. String where=CHAT_ID+"=?";
68. String[] whereValue={Integer.toString(id)};
69. ContentValues cv=new ContentValues();
70. cv.put(CHAT_Name, chatname);
71. cv.put(CHAT_Time, chattime);
72. cv.put(CHAT_Info, chatinfo);
73. db.update(TABLE_NAME, cv, where, whereValue);
74. }
76. public void delall(){
77. SQLiteDatabase db=this.getReadableDatabase();
78. String sql=" DROP TABLE IF EXISTS "+TABLE_NAME;
79. db.execSQL(sql);
80. onCreate(db);
81. }
84. }

形如“聊天記錄”這種雖沒有十分復雜的存儲結構，也是適宜存在表中，

而xml大概多是用以傳輸數據或存儲少量不常用改動的數據把~