- package com.nyl.sql;
- import android.app.Activity;
- import android.content.ContentValues;
- import android.content.Context;
- import android.database.Cursor;
- import android.database.sqlite.SQLiteDatabase;
- import android.support.v7.app.AppCompatActivity;
- import android.os.Bundle;
- import android.view.View;
- import android.widget.Button;
- import android.widget.Toast;
- /**
- * 增删改查
- */
- public class NewDate extends Activity implements View.OnClickListener {
- private Button btnAdd;
- private Button btnDelete;
- private Button btnModify;
- private Button btnFind;
- DatabaseHelper databaseHelper = null;
- SQLiteDatabase db = null;
- Context context = null;
- //数据库字段
- public final static String TABLE_NAME = "test";
- public final static String ID = "id";
- public final static String NAME = "name";
- public final static String HP = "hp";
- public final static String MP = "mp";@Override protected void onCreate(Bundle savedInstanceState) {
- super.onCreate(savedInstanceState);
- setContentView(R.layout.new_date);
- context = this;
- //创建DatabaseHelper对象
- databaseHelper = DatabaseHelper.getInstance(context);
- //调用getReadableDatabase方法,如数据库不存在则创建,如果存在则打开
- db = databaseHelper.getReadableDatabase();
- initView(); //初始化布局控件
- //给数据库表写入一些信息
- for (int i = 0; i < 10; i++) {
- insert(NAME, "农美眉" + i);
- }
- }
- private void initView() {
- btnAdd = (Button) findViewById(R.id.btnAdd);
- btnDelete = (Button) findViewById(R.id.btnDelete);
- btnModify = (Button) findViewById(R.id.btnModify);
- btnFind = (Button) findViewById(R.id.btnFind);
- btnAdd.setOnClickListener(this);
- btnDelete.setOnClickListener(this);
- btnModify.setOnClickListener(this);
- btnFind.setOnClickListener(this);
- }@Override public void onClick(View view) {
- //添加
- if (view.getId() == R.id.btnAdd) {
- insert(NAME, "衣服");
- Toast.makeText(NewDate.this, "添加一条数据名称为衣服", Toast.LENGTH_SHORT).show();
- }
- //删除
- if (view.getId() == R.id.btnDelete) {
- delete(ID, "1");
- Toast.makeText(NewDate.this, "删除一条id=1的数据", Toast.LENGTH_SHORT).show();
- }
- //修改
- if (view.getId() == R.id.btnModify) {
- update(NAME, "连衣裙", "漂亮");
- Toast.makeText(NewDate.this, "更新名称连衣裙为漂亮", Toast.LENGTH_SHORT).show();
- }
- //查找
- if (view.getId() == R.id.btnFind) {
- Cursor cursor = find(ID, "3");
- String name = cursor.getString(cursor.getColumnIndex(NAME));
- Toast.makeText(NewDate.this, "查找ID为3数据的名称是" + name, Toast.LENGTH_SHORT).show();
- }
- }
- //插入一条数据
- public void insert(String name, String s) {
- ContentValues values = new ContentValues();
- values.put(name, s);
- db.insert(TABLE_NAME, null, values);
- }
- //删除一条数据
- public void delete(String id, String s) {
- db.delete(TABLE_NAME, id + "=?", new String[] {
- s
- });
- }
- //更新一条数据
- public void update(String key, String oldDate, String newDate) {
- ContentValues values = new ContentValues();
- values.put(key, newDate);
- db.update(TABLE_NAME, values, key + "=?", new String[] {
- oldDate
- });
- }
- //查找一条数据
- public Cursor find(String id, String s) {
- Cursor cursor = db.query(TABLE_NAME, null, id + "=?", new String[] {
- s
- },
- null, null, null);
- if (cursor != null) {
- cursor.moveToFirst();
- }
- return cursor;
- }
- }
来源: http://www.bubuko.com/infodetail-1986216.html