<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical"> <Button android:id="@+id/create" android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="创建数据库" /> <Button android:id="@+id/insert" android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="插入数据库" /> <Button android:id="@+id/update" android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="更新数据库" /> <Button android:id="@+id/query" android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="查询数据库" /> <Button android:id="@+id/delete" android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="删除数据库" /> </LinearLayout>
package com.example.sqlite; import android.app.Activity; import android.content.ContentValues; import android.database.Cursor; import android.database.sqlite.SQLiteDatabase; import android.os.Bundle; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.Toast; public class MainActivity extends Activity implements OnClickListener{ private Button create; private Button insert; private Button query; private Button update; private Button delete; private MyDBhelper dbHelper; SQLiteDatabase db; Cursor cursor; public static int counter=0; public String name,sex; protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); initView(); } private void initView(){ create=(Button) findViewById(R.id.create); insert=(Button) findViewById(R.id.insert); query=(Button) findViewById(R.id.query); update=(Button) findViewById(R.id.update); delete=(Button) findViewById(R.id.delete); create.setOnClickListener(this); insert.setOnClickListener(this); query.setOnClickListener(this); update.setOnClickListener(this); delete.setOnClickListener(this); } private void createDB(){ dbHelper=new MyDBhelper(this); db=dbHelper.getWritableDatabase(); Toast.makeText(this, "创建成功!", Toast.LENGTH_SHORT).show(); } private void insertDB(){ counter++; name="用户"+counter; if(counter%2==0){ sex="male"; }else{ sex="female"; } dbHelper=new MyDBhelper(this); db=dbHelper.getWritableDatabase(); ContentValues cv=new ContentValues(); cv.put("name",name); cv.put("age",26); cv.put("sex",sex); db.insert(MyDBhelper.TABLE_NAME, null, cv); Toast.makeText(this, name+"添加成功!", Toast.LENGTH_SHORT).show(); db.close(); } private void queryDB(){ dbHelper=new MyDBhelper(this); SQLiteDatabase rdb=dbHelper.getReadableDatabase(); cursor=rdb.query(MyDBhelper.TABLE_NAME, null, null, null, null, null, null); StringBuffer sb=new StringBuffer(); while(cursor.moveToNext()){ String rs=cursor.getInt(cursor.getColumnIndex(MyDBhelper.ID))+","+cursor.getString(cursor.getColumnIndex(MyDBhelper.NAME))+","+cursor.getInt(cursor.getColumnIndex(MyDBhelper.AGE))+","+cursor.getString(cursor.getColumnIndex(MyDBhelper.SEX))+"\n"; sb.append(rs); } Toast.makeText(this, sb.toString(), Toast.LENGTH_LONG).show(); db.close(); } private void deleteDB(){ dbHelper=new MyDBhelper(this); db=dbHelper.getWritableDatabase(); String whereClause="_id>?"; String[] whereArgs={String.valueOf(1)}; db.delete(MyDBhelper.TABLE_NAME, whereClause, whereArgs); db.close(); Toast.makeText(this, "删除成功!", Toast.LENGTH_SHORT).show(); } private void updateDB(){ dbHelper=new MyDBhelper(this); db=dbHelper.getWritableDatabase(); ContentValues values=new ContentValues(); values.put("age", 21); String whereClause="name=?"; String[] whereArgs={String.valueOf("小强")}; db.update(MyDBhelper.TABLE_NAME, values, whereClause, whereArgs); db.close(); Toast.makeText(this, "更新成功!", Toast.LENGTH_SHORT).show(); } public void onClick(View v) { switch (v.getId()) { case R.id.create: createDB(); break; case R.id.insert: insertDB(); break; case R.id.query: queryDB(); break; case R.id.update: updateDB(); break; case R.id.delete: deleteDB(); break; } } }
package com.example.sqlite; import android.content.Context; import android.database.sqlite.SQLiteDatabase; import android.database.sqlite.SQLiteOpenHelper; public class MyDBhelper extends SQLiteOpenHelper{ public static final String ID="_id"; public static final String NAME="name"; public static final String AGE="age"; public static final String SEX="sex"; public static final String TABLE_NAME="person"; public MyDBhelper(Context context) { super(context,"persons", null,1); } public void onCreate(SQLiteDatabase db) { db.execSQL("CREATE TABLE "+TABLE_NAME+"("+ ID+" INTEGER PRIMARY KEY AUTOINCREMENT," +NAME+" TEXT NOT NULL," +AGE+" INTEGER," +SEX+" TEXT"+")"); System.out.println("database created!"); } public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { System.out.println("database update!"); } }