Android資料庫增刪改查
阿新 • • 發佈：2020-11-22
1 <?xml version="1.0" encoding="UTF-8"?> 2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 3 android:layout_width="match_parent" 4 android:layout_height="match_parent" 5 android:background="@drawable/bg" 6 android:orientation="vertical" 7 android:padding="16dp" > 8 9 10 <LinearLayout 11 android:layout_width="match_parent" 12 android:layout_height="wrap_content" 13 android:layout_marginTop="130dp" > 14 15 <TextView 16 android:layout_width="wrap_content" 17 android:layout_height="wrap_content" 18 android:text="姓 名 ：" 19 android:textSize="18sp" /> 20 21 <EditText 22 android:id="@+id/et_name" 23 android:layout_width="match_parent" 24 android:layout_height="wrap_content" 25 android:hint="請輸入姓名" 26 android:textSize="16sp" /> 27 </LinearLayout> 28 29 30 <LinearLayout 31 android:layout_width="match_parent" 32 android:layout_height="wrap_content" 33 android:layout_marginBottom="10dp" > 34 35 <TextView 36 android:layout_width="wrap_content" 37 android:layout_height="wrap_content" 38 android:text="年 齡：" 39 android:textSize="18sp" /> 40 41 <EditText 42 android:id="@+id/et_age" 43 android:layout_width="match_parent" 44 android:layout_height="wrap_content" 45 android:hint="輸入年齡" 46 android:textSize="16sp" /> 47 </LinearLayout> 48 49 50 <LinearLayout 51 android:layout_width="match_parent" 52 android:layout_height="wrap_content" > 53 54 <Button 55 android:id="@+id/btn_add" 56 android:layout_width="0dp" 57 android:layout_height="wrap_content" 58 android:layout_marginRight="2dp" 59 android:layout_weight="1" 60 android:background="#B9B9FF" 61 android:onClick="add" 62 android:text="新增" 63 android:textSize="18sp" /> 64 65 <Button 66 android:id="@+id/btn_search" 67 android:layout_width="0dp" 68 android:layout_height="wrap_content" 69 android:layout_marginRight="2dp" 70 android:layout_weight="1" 71 android:background="#DCB5FF" 72 android:onClick="search" 73 android:text="查詢" 74 android:textSize="18sp" /> 75 76 <Button 77 android:id="@+id/btn_update" 78 android:layout_width="0dp" 79 android:layout_height="wrap_content" 80 android:layout_marginRight="2dp" 81 android:layout_weight="1" 82 android:background="#E6CAFF" 83 android:onClick="update" 84 android:text="修改" 85 android:textSize="18sp" /> 86 87 <Button 88 android:id="@+id/btn_delete" 89 android:layout_width="0dp" 90 android:layout_height="wrap_content" 91 android:layout_weight="1" 92 android:background="#ACD6FF" 93 android:onClick="delete" 94 android:text="刪除" 95 android:textSize="18sp" /> 96 </LinearLayout> 97 98 <TextView 99 android:id="@+id/tv_show" 100 android:layout_width="match_parent" 101 android:layout_height="wrap_content" 102 android:layout_marginTop="25dp" 103 android:textSize="20sp" /> 104 105 </LinearLayout>
1 package com.example.myapplication; 2 import android.os.Bundle; 3 import android.app.Activity; 4 import android.database.Cursor; 5 import android.database.sqlite.SQLiteDatabase; 6 import android.view.View; 7 import android.widget.EditText; 8 import android.widget.TextView; 9 import android.widget.Toast; 10 11 public class MainActivity extends Activity { 12 13 @Override 14 protected void onCreate(Bundle savedInstanceState) { 15 super.onCreate(savedInstanceState); 16 setContentView(R.layout.activity_main); 17 } 18 19 public void add(View v) { 20 StuOpenHelper helper = new StuOpenHelper(this); 21 SQLiteDatabase db = helper.getWritableDatabase(); 22 String name = ((EditText) findViewById(R.id.et_name)).getText() 23 .toString(); 24 int age = Integer.parseInt(((EditText) findViewById(R.id.et_age)) 25 .getText().toString()); 26 27 db.execSQL("insert into stuinfo (name,age) values(?,?)", new Object[]{ 28 name, age}); 29 Toast.makeText(this, "新增成功", Toast.LENGTH_SHORT).show(); 30 31 } 32 33 public void delete(View view) { 34 StuOpenHelper helper = new StuOpenHelper(this); 35 SQLiteDatabase db = helper.getWritableDatabase(); 36 db.execSQL("delete from stuinfo where _id=?", new Object[]{2}); 37 Toast.makeText(this, "刪除成功", Toast.LENGTH_SHORT).show(); 38 39 } 40 41 public void update(View view) { 42 StuOpenHelper helper = new StuOpenHelper(this); 43 SQLiteDatabase db = helper.getWritableDatabase(); 44 db.execSQL("update stuinfo set name=? where _id=?", new Object[]{ 45 "micky", 3}); 46 Toast.makeText(this, "修改成功", Toast.LENGTH_SHORT).show(); 47 48 } 49 50 public void search(View view) { 51 StuOpenHelper helper = new StuOpenHelper(this); 52 SQLiteDatabase db = helper.getWritableDatabase(); 53 String s = ""; 54 Cursor cursor = db.rawQuery("select * from stuinfo", null); 55 if (cursor.getCount() != 0) { 56 57 while (cursor.moveToNext()) { 58 s += cursor.getInt(0) + " " + cursor.getString(1) + " " 59 + cursor.getInt(2) + "\n"; 60 } 61 } 62 63 // Toast.makeText(this, s, 0).show(); 64 ((TextView) (findViewById(R.id.tv_show))).setText(s); 65 66 } 67 68 }
1 package com.example.myapplication; 2 3 import android.content.Context; 4 import android.database.sqlite.SQLiteDatabase; 5 import android.database.sqlite.SQLiteOpenHelper; 6 7 public class StuOpenHelper extends SQLiteOpenHelper { 8 public StuOpenHelper(Context context) { 9 super(context, "stu.db", null, 1); 10 // TODO Auto-generated constructor stub 11 } 12 13 @Override 14 public void onCreate(SQLiteDatabase db) { 15 // TODO Auto-generated method stub 16 db.execSQL("create table stuinfo(_id integer primary key autoincrement,name varchar(20),age integer)"); 17 18 } 19 20 @Override 21 public void onUpgrade(SQLiteDatabase arg0, int arg1, int arg2) { 22 // TODO Auto-generated method stub 23 24 } 25 26 }