Android SQLite的CRUD

activity12.java

1. package com.wansha;
3. import Android.app.Activity;
4. import android.content.ContentValues;
5. import android.database.Cursor;
6. import android.database.sqlite.SQLiteDatabase;
7. import android.database.sqlite.SQLiteOpenHelper;
8. import android.os.Bundle;
9. import android.view.View;
10. import android.view.View.OnClickListener;
11. import android.widget.Button;
13. import com.wansha.db.DatabaseHelper;
15. public class Activity12 extends Activity {
16. private Button createDatabase;
17. private Button updateDatabase;
18. private Button insert;
19. private Button update;
20. private Button read;
21. private Button delete;
22. /** Called when the activity is first created. */
23. @Override
24. public void onCreate(Bundle savedInstanceState) {
25. super.onCreate(savedInstanceState);
26. setContentView(R.layout.main);
27. this.createDatabase = (Button)this.findViewById(R.id.createDatabase);
28. this.createDatabase.setOnClickListener(new CreateDatabaseListener());
30. this.updateDatabase = (Button)this.findViewById(R.id.updateDatabase);
31. this.updateDatabase.setOnClickListener(new UpdateDatabaseListener());
33. this.insert = (Button)this.findViewById(R.id.insert);
34. this.insert.setOnClickListener(new InsertListener());
36. this.update = (Button)this.findViewById(R.id.update);
37. this.update.setOnClickListener(new UpdateListener());
39. this.read = (Button)this.findViewById(R.id.read);
40. this.read.setOnClickListener(new ReadListener());
42. this.delete = (Button)this.findViewById(R.id.delete);
43. this.delete.setOnClickListener(new DeleteListener());
45. }
46. class CreateDatabaseListener implements OnClickListener{
47. @Override
48. public void onClick(View v) {
49. SQLiteOpenHelper sqlite = new DatabaseHelper(Activity12.this,"sharp");
50. sqlite.getReadableDatabase();
51. }
52. }
53. class UpdateDatabaseListener implements OnClickListener{
54. @Override
55. public void onClick(View v) {
56. System.out.println("UpdateDatabaseListener is invoked !!!");
57. SQLiteOpenHelper sqlite = new DatabaseHelper(Activity12.this,"sharp",2);
58. sqlite.getReadableDatabase();
59. }
60. }
61. class InsertListener implements OnClickListener{
62. @Override
63. public void onClick(View v) {
64. SQLiteOpenHelper sqlite = new DatabaseHelper(Activity12.this,"sharp");
65. SQLiteDatabase database = sqlite.getWritableDatabase();
66. ContentValues values = new ContentValues();
67. values.put("username", "xiaopeng");
68. database.insert("sharp", null, values);
69. }
70. }
71. class UpdateListener implements OnClickListener{
72. @Override
73. public void onClick(View v) {
74. SQLiteOpenHelper sqlite = new DatabaseHelper(Activity12.this,"sharp");
75. SQLiteDatabase database = sqlite.getWritableDatabase();
76. ContentValues values = new ContentValues();
77. values.put("username", "pengpeng");
78. database.update("sharp", values, "id=?", new String[]{"2"});
79. }
80. }
81. class ReadListener implements OnClickListener{
82. @Override
83. public void onClick(View v) {
84. SQLiteOpenHelper sqlite = new DatabaseHelper(Activity12.this,"sharp");
85. SQLiteDatabase database = sqlite.getWritableDatabase();
86. Cursor cursor = database.query("sharp", new String[]{"id","username"}, null, null, null, null, null);
87. while(cursor.moveToNext()){
88. String username = cursor.getString(cursor.getColumnIndex("username"));
89. System.out.println("username---->" + username);
90. }
91. }
92. }
93. class DeleteListener implements OnClickListener{
94. @Override
95. public void onClick(View v) {
96. SQLiteOpenHelper sqlite = new DatabaseHelper(Activity12.this,"sharp");
97. SQLiteDatabase database = sqlite.getWritableDatabase();
98. database.delete("sharp", "id=?", new String[]{"1"});
99. }
100. }
101. }

1. <?xml version="1.0" encoding="utf-8"?>
2. <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
3. android:layout_width="fill_parent"
4. android:layout_height="fill_parent"
5. android:orientation="vertical" >
7. <Button android:id="@+id/createDatabase"
8. android:layout_width="fill_parent"
9. android:layout_height="wrap_content"
10. android:text="創建數據庫"
11. />
12. <Button android:id="@+id/updateDatabase"
13. android:layout_width="fill_parent"
14. android:layout_height="wrap_content"
15. android:text="更新數據庫"
16. />
17. <Button android:id="@+id/insert"
18. android:layout_width="fill_parent"
19. android:layout_height="wrap_content"
20. android:text="插入數據"
21. />
22. <Button android:id="@+id/update"
23. android:layout_width="fill_parent"
24. android:layout_height="wrap_content"
25. android:text="更新數據"
26. />
27. <Button android:id="@+id/read"
28. android:layout_width="fill_parent"
29. android:layout_height="wrap_content"
30. android:text="讀取數據"
31. />
32. <Button android:id="@+id/delete"
33. android:layout_width="fill_parent"
34. android:layout_height="wrap_content"
35. android:text="刪除數據"
36. />
37. </LinearLayout>

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

創建自增長ID

DatebaseHelper.java

1. package com.wansha.db;
3. import android.content.Context;
4. import android.database.sqlite.SQLiteDatabase;
5. import android.database.sqlite.SQLiteDatabase.CursorFactory;
6. import android.database.sqlite.SQLiteOpenHelper;
8. public class DatabaseHelper extends SQLiteOpenHelper{
9. private static final int VERSION = 1;
10. public DatabaseHelper(Context context, String name, CursorFactory factory,
11. int version) {
12. super(context, name, factory, version);
13. }
14. public DatabaseHelper(Context context, String name,int version) {
15. this(context, name, null, version);
16. }
17. public DatabaseHelper(Context context, String name) {
18. this(context, name, VERSION);
19. }
20. @Override
21. public void onCreate(SQLiteDatabase db) {
22. System.out.println("create table is invoked !!!");
23. db.execSQL("create table sharp(id integer primary key autoincrement, username varchar(255))");
24. }
25. @Override
26. public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
27. System.out.println("update table is invoked !!!");
28. }
30. }