SQLite的CRUD

1. packagecom.wansha;
3. importandroid.app.Activity;
4. importandroid.content.ContentValues;
5. importandroid.database.Cursor;
6. importandroid.database.sqlite.SQLiteDatabase;
7. importandroid.database.sqlite.SQLiteOpenHelper;
8. importandroid.os.Bundle;
9. importandroid.view.View;
10. importandroid.view.View.OnClickListener;
11. importandroid.widget.Button;
12. importcom.wansha.db.DatabaseHelper;
13. publicclassActivity12extendsActivity{
14. privateButtoncreateDatabase;
15. privateButtonupdateDatabase;
16. privateButtoninsert;
17. privateButtonupdate;
18. privateButtonread;
19. privateButtondelete;
20. /**Calledwhentheactivityisfirstcreated.*/
21. @Override
22. voidonCreate(BundlesavedInstanceState){
23. super.onCreate(savedInstanceState);
24. setContentView(R.layout.main);
25. this.createDatabase=(Button)this.findViewById(R.id.createDatabase);
26. this.createDatabase.setOnClickListener(newCreateDatabaseListener());
28. this.updateDatabase=(Button)this.findViewById(R.id.updateDatabase);
29. this.updateDatabase.setOnClickListener(newUpdateDatabaseListener());
30. this.insert=(Button)this.findViewById(R.id.insert);
31. this.insert.setOnClickListener(newInsertListener());
32. this.update=(Button)this.findViewById(R.id.update);
33. this.update.setOnClickListener(newUpdateListener());
34. this.read=(Button)this.findViewById(R.id.read);
35. this.read.setOnClickListener(newReadListener());
36. this.delete=(Button)this.findViewById(R.id.delete);
37. this.delete.setOnClickListener(newDeleteListener());
38. }
39. classCreateDatabaseListenerimplementsOnClickListener{
40. voidonClick(Viewv){
41. SQLiteOpenHelpersqlite=newDatabaseHelper(Activity12.this,"sharp");
42. sqlite.getReadableDatabase();
43. }
44. classUpdateDatabaseListenerimplementsOnClickListener{
45. @Override
46. voidonClick(Viewv){
47. System.out.println("UpdateDatabaseListenerisinvoked!!!");
48. "sharp",2);
49. classInsertListener SQLiteOpenHelpersqlite="sharp");
50. SQLiteDatabasedatabase=sqlite.getWritableDatabase();
51. ContentValuesvalues=newContentValues();
52. values.put("username","xiaopeng");
53. database.insert("sharp",null,values);
54. classUpdateListener"pengpeng");
55. database.update("sharp",values,"id=?",153); background-color:inherit; font-weight:bold">newString[]{"2"});
56. classReadListener Cursorcursor=database.query("sharp",153); background-color:inherit; font-weight:bold">newString[]{"id","username"},153); background-color:inherit; font-weight:bold">null);
57. while(cursor.moveToNext()){
58. Stringusername=cursor.getString(cursor.getColumnIndex("username"));
59. System.out.println("username---->"+username);
60. classDeleteListener database.delete("sharp",153); background-color:inherit; font-weight:bold">newString[]{"1"});
61. }

<?xmlversion="1.0"encoding="utf-8"?>
1. <LinearLayoutxmlns:android="http://schemas.android.com/apk/res/android"
2. android:layout_width="fill_parent"
3. android:layout_height="fill_parent"
4. android:orientation="vertical">
5. Buttonandroid:id="@+id/createDatabase"
6. android:layout_width="fill_parent"
7. android:layout_height="wrap_content"
8. android:text="创建数据库"
9. />
10. Buttonandroid:id="@+id/updateDatabase"
11. android:layout_height="wrap_content"
12. android:text="更新数据库"
13. />
14. Buttonandroid:id="@+id/insert"
15. android:text="插入数据"
16. Buttonandroid:id="@+id/update"
17. android:text="更新数据"
18. Buttonandroid:id="@+id/read"
19. android:text="读取数据"
20. Buttonandroid:id="@+id/delete"
21. android:text="删除数据"
22. </LinearLayout>

db.execSQL("create table sharp(id integer primary key autoincrement,username varchar(255))");

创建自增长ID

DatebaseHelper.java

packagecom.wansha.db;
1. importandroid.content.Context;
2. importandroid.database.sqlite.SQLiteDatabase.CursorFactory;
3. importandroid.database.sqlite.SQLiteOpenHelper;
4. classDatabaseHelperextendsSQLiteOpenHelper{
5. privatestaticfinalintVERSION=1;
6. publicDatabaseHelper(Contextcontext,Stringname,CursorFactoryfactory,
7. intversion){
8. super(context,name,factory,version);
9. intversion){
10. this(context,version);
12. voidonCreate(SQLiteDatabasedb){
13. System.out.println("createtableisinvoked!!!");
14. db.execSQL("createtablesharp(idintegerprimarykeyautoincrement,usernamevarchar(255))");
15. voidonUpgrade(SQLiteDatabasedb,153); background-color:inherit; font-weight:bold">intoldVersion,153); background-color:inherit; font-weight:bold">intnewVersion){
16. System.out.println("updatetableisinvoked!!!");
17. }

（编辑：李大同）

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