SQLite小例子

这是我在网站看到过一个网友做的sqlite一个小程序，觉得写的不错，以供提示参考，所以把转载下来了。其实就是一个小收藏夹。

代码如下：

ActivityMain_1.java

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01.public class ActivityMain_1 extends Activity {
02. //声明EditText实例
03. private EditText et1,et2,et3;
04. //声明Button实例
05. private Button button;
06.
07. @Override
08. protected void onCreate(Bundle savedInstanceState) {
09. // TODO Auto-generated method stub
10. super.onCreate(savedInstanceState);
11. setContentView(R.layout.main_1);
12.
13. //根据ID获得实例对象
14. et1 = (EditText) findViewById(R.id.EditText01);
15. et2 = (EditText) findViewById(R.id.EditText02);
16. et3 = (EditText) findViewById(R.id.EditText03);
17. button = (Button) findViewById(R.id.button);
18.
19. //事件
20. button.setOnClickListener(new View.OnClickListener() {
21.
22. @Override
23. public void onClick(View v) {
24. String name=et1.getText().toString();
25. String url =et2.getText().toString();
26. String desc = et3.getText().toString();
27.
28. ContentValues values = new ContentValues();
29.
30. values.put("name",name);
31. values.put("url",url);
32. values.put("desc",desc);
33.
34. //实例化数据库帮助类
35. DBHelper helper = new DBHelper(getApplicationContext());
36. //打开数据库
37. helper.open();
38.
39. //插入数据
40. helper.insert(values);
41. //实例化Intent
42. Intent intent = new Intent(ActivityMain_1.this,QueryActivity.class);
43. startActivity(intent);
44. helper.close();
45. }
46. });
47.
48. }
49.
50.
51.}

QueryActivity.java

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01.public class QueryActivity extends ListActivity {
02.
03. private ListView listView;
04. private Cursor c;
05.
06. @Override
07. protected void onCreate(Bundle savedInstanceState) {
08. // TODO Auto-generated method stub
09. super.onCreate(savedInstanceState);
10. //setContentView(R.layout.row);
11.
12. //实例化数据库帮助类
13. final DBHelper help = new DBHelper(this);
14. help.open();
15. c= help.query();
16. query();
17. //提示对话框
18. final AlertDialog.Builder builder = new AlertDialog.Builder(this);
19. listView.setOnItemClickListener(new OnItemClickListener() {
20. @Override
21. public void onItemClick(AdapterView<?> parent,View view,
22. int position,long id) {
23. final long temp = id;
24. builder.setMessage("真的要删除该条记录吗？").setPositiveButton("是",new DialogInterface.OnClickListener() {
25.
26. @Override
27. public void onClick(DialogInterface dialog,int which) {
28. System.out.println("yes");
29. help.del((int)temp);
30. //重新查询
31. //query();
32. Cursor c = help.query();
33. //列表项数组
34. String[] from ={"_id","name","url","desc"};
35. //列表项ID
36. int[] to ={R.id.text0,R.id.text1,R.id.text2,R.id.text3};
37. //适配器
38. SimpleCursorAdapter adapter = new SimpleCursorAdapter(getApplicationContext(),R.layout.row,c,from,to);
39. ListView listView = getListView();
40. listView.setAdapter(adapter);
41.
42.
43. }
44. }).setNegativeButton("否",new DialogInterface.OnClickListener() {
45.
46. @Override
47. public void onClick(DialogInterface dialog,int which) {
48. // TODO Auto-generated method stub
49.
50. }
51. });
52. builder.create();
53. builder.show();
54. }
55. });
56.
57. }
58. @Override
59. protected void onStop() {
60. // TODO Auto-generated method stub
61. super.onStop();
62.
63. }
64. public void query(){
65. //列表项数组
66. String[] from ={"_id","desc"};
67. //列表项ID
68. int[] to ={R.id.text0,R.id.text3};
69.
70. //适配器
71. SimpleCursorAdapter adapter = new SimpleCursorAdapter(this,to);
72. //adapter.notifyDataSetChanged();
73. //列表视图
74. listView = getListView();
75. //为列表视图添加适配器
76. listView.setAdapter(adapter);
77.
78. }
79.
80.
81.}

DBHelper.java

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01.public class DBHelper extends sqliteOpenHelper {
02.
03. private static final String DB_NAME="coll.db";
04. //表名
05. private static final String TBL_NAME="logtable";
06. //创建sql语句
07. private static final String CREATE_TBL = "create table logtable " +
08. "(_id integer primary key autoincrement,name text,url text,desc text)";
09. //sqliteDatabase实例
10. private sqliteDatabase db;
11.
12. public DBHelper(Context context) {
13. super(context,DB_NAME,null,2);
14.
15. }
16. @Override
17. public void onCreate(sqliteDatabase db) {
18.
19. db.execsql(CREATE_TBL);
20. }
21.
22. //打开数据库
23. public void open(){
24. db = getWritableDatabase();
25. }
26.
27. @Override
28. public void onUpgrade(sqliteDatabase db,int oldVersion,int newVersion) {
29. // TODO Auto-generated method stub
30. }
31.
32. //插入方法
33. public void insert(ContentValues values){
34.
35. db.insert(TBL_NAME,values);
36. }
37.
38. //查询方法
39. public Cursor query(){
40. Cursor c = db.query(TBL_NAME,null);
41. return c;
42. }
43.
44. //删除方法
45. public void del(int id){
46. db.delete(TBL_NAME,"_id=?",new String[]{String.valueOf(id)});
47. }
48.
49. //关闭数据库
50. public void close(){
51. if (db != null){
52. db.close();
53. }
54. }
55.}

main_1.xml

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01.<?xml version="1.0" encoding="UTF-8"?>
02.<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
03. android:orientation="vertical"
04. android:layout_width="fill_parent"
05. android:layout_height="fill_parent"
06. >
07.
08. <TextView
09. android:id="@+id/TextView01"
10. android:layout_width="fill_parent"
11. android:layout_height="wrap_content"
12. android:text="网站名称"
13. />
14. <EditText
15. android:id="@+id/EditText01"
16. android:layout_width="fill_parent"
17. android:layout_height="wrap_content"
18.
19. />
20. <TextView
21. android:id="@+id/TextView02"
22. android:layout_width="fill_parent"
23. android:layout_height="wrap_content"
24. android:text="URL"
25. />
26. <EditText
27. android:id="@+id/EditText02"
28. android:layout_width="fill_parent"
29. android:layout_height="wrap_content"
30. />
31. <TextView
32. android:id="@+id/TextView03"
33. android:layout_width="fill_parent"
34. android:layout_height="wrap_content"
35. android:text="网站描述"
36. />
37. <EditText
38. android:id="@+id/EditText03"
39. android:layout_width="fill_parent"
40. android:layout_height="wrap_content"
41. android:height="100px"
42. />
43.
44. <Button
45. android:id="@+id/button"
46. android:layout_width="wrap_content"
47. android:layout_height="wrap_content"
48. android:text="添加"
49. />
50.</LinearLayout>

自定义布局：row.xml

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01.<?xml version="1.0" encoding="UTF-8"?>
02.<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
03. android:orientation="horizontal"
04. android:layout_width="fill_parent"
05. android:layout_height="fill_parent"
06. android:layout_gravity="center_vertical"
07. >
08.
09. <TextView
10. android:id="@+id/text0"
11. android:layout_width="wrap_content"
12. android:layout_height="wrap_content"
13. android:paddingRight="10px"
14. />
15. <TextView
16. android:id="@+id/text1"
17. android:layout_width="wrap_content"
18. android:layout_height="wrap_content"
19. android:paddingRight="10px"
20. />
21. <TextView
22. android:id="@+id/text2"
23. android:layout_width="wrap_content"
24. android:layout_height="wrap_content"
25. android:paddingRight="10px"
26. />
27. <TextView
28. android:id="@+id/text3"
29. android:layout_width="wrap_content"
30. android:layout_height="wrap_content"
31. android:paddingRight="10px"
32. />
33.
34.</LinearLayout>

结果如图所示：

SQLite小例子

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