006_01SQLite_demo
时间：2021-07-01 10:21:17
帮助过：4人阅读
package com.example.sqlitedemo;
2
3 import android.app.Activity;
4 import android.database.Cursor;
5 import android.database.sqlite.SQLiteDatabase;
6 import android.os.Bundle;
7 import android.util.Log;
8 import android.view.Menu;
9 import android.view.MenuItem;
10 import android.view.View;
11
12 public class MainActivity
extends Activity {
13 SQLiteDatabase db =
null;
14 public static String TAG = "sqlitedemo"
;
15 @Override
16 protected void onCreate(Bundle savedInstanceState) {
17 super.onCreate(savedInstanceState);
18 setContentView(R.layout.activity_main);
19
20 db = SQLiteDatabase.openOrCreateDatabase(getFilesDir()+"/userinfo.db",
null);
21
22 createTable(db);
23 }
24 public void insert(View v){
25 insert(db);
26 }
27 public void delete(View v){
28 delete(db);
29 }
30 public void update(View v){
31 update(db);
32 }
33 public void query(View v){
34 query(db);
35 }
36
37 private void update(SQLiteDatabase db){
38 String update = "update user set password=? where id = ?"
;
39 Object[] args = {"99999999", 5
};
40 db.execSQL(update, args);
41 }
42
43 private void delete(SQLiteDatabase db){
44 String delete = "delete from user where id =?"
;
45 Object[] args = {5
};
46 db.execSQL(delete, args);
47 }
48
49 private void query(SQLiteDatabase db){
50 String query = "select * from user"
;
51 Cursor resultSet = db.rawQuery(query,
null);
52
53 int row =
resultSet.getCount();
54 Log.i(TAG, row+""
);
55
56 while(resultSet.moveToNext()){
57 int id = resultSet.getInt(0
);
58 String username = resultSet.getString(1
);
59 String password = resultSet.getString(2
);
60 Log.i(TAG, id + "," +username+ "," +
password);
61
62 }
63
64 }
65 private void insert(SQLiteDatabase db){
66 String insert = "insert into user values(?,?,?)"
;
67 Object[] args = {5, "user5", "55555555"
};
68 db.execSQL(insert, args);
69 }
70
71 private void createTable(SQLiteDatabase db){
72 String createtable = "create table user(id int, name varchar(20),password char(8))"
;
73 db.execSQL(createtable);
74 }
75
76
77 }
MainActivity.java
1 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
2 xmlns:tools="http://schemas.android.com/tools"
3 android:layout_width="match_parent"
4 android:layout_height="match_parent"
5 android:orientation="vertical"
6 android:paddingBottom="@dimen/activity_vertical_margin"
7 android:paddingLeft="@dimen/activity_horizontal_margin"
8 android:paddingRight="@dimen/activity_horizontal_margin"
9 android:paddingTop="@dimen/activity_vertical_margin"
10 tools:context="com.example.sqlitedemo.MainActivity" >
11
12 <TextView
13 android:layout_width="wrap_content"
14 android:layout_height="wrap_content"
15 android:text="@string/hello_world" />
16
17 <Button
18 android:layout_width="fill_parent"
19 android:layout_height="wrap_content"
20 android:onClick="insert"
21 android:text="insert" />
22
23 <Button
24 android:layout_width="fill_parent"
25 android:layout_height="wrap_content"
26 android:onClick="delete"
27 android:text="delete" />
28
29 <Button
30 android:layout_width="fill_parent"
31 android:layout_height="wrap_content"
32 android:onClick="update"
33 android:text="update" />
34
35 <Button
36 android:layout_width="fill_parent"
37 android:layout_height="wrap_content"
38 android:onClick="query"
39 android:text="query" />
40
41 </LinearLayout>
activity_main.xml
增删改查界面：
006_01SQLite_demo
标签：
