Android SQLite demo 之增、删、改、查

最终效果动画

MainActivity

package com.example.shen.sqlitetest;

import android.app.Activity;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.view.View;
import android.view.WindowManager;
import android.widget.AdapterView;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;

import com.example.shen.sqlitetest.entity.User;

import java.util.ArrayList;


public class MainActivity extends Activity {
    private SQLiteDatabase db;
    private EditText etUserName,etPassword;
    private ArrayList<User> alUser;
    private ListView lvUser;
    private UserAdapter adapter;
    private TextView tvPosition;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        hideSoftKeyboard();
        initView();
        initData();
    }

    private void initView(){
        DatabaseHelper databaseHelper=new DatabaseHelper(MainActivity.this);
        db=null;
        db=databaseHelper.getReadableDatabase();

        etUserName=(EditText) findViewById(R.id.et_username);
        etPassword=(EditText) findViewById(R.id.et_password);
        lvUser=(ListView) findViewById(R.id.lv_user);


        alUser=new ArrayList<>();
        adapter=new UserAdapter(this,alUser);
        lvUser.setAdapter(adapter);
        lvUser.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                etUserName.setText(alUser.get(position).username);
                etUserName.setSelection(etUserName.length());
                etPassword.setText(alUser.get(position).password);
            }
        });

        //新增
        findViewById(R.id.bt_insert).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (etUserName.getText().toString().isEmpty() || etPassword.getText().toString().isEmpty()) {
                    Toast.makeText(MainActivity.this,getString(R.string.can_not_be_empty),Toast.LENGTH_SHORT).show();
                } else {
                    String sql = "insert into user(username,password) values ('" + etUserName.getText().toString().trim() + "','" + etPassword.getText().toString().trim() + "')";
                    db.execSQL(sql);
                    initData();
                }
            }
        });

        //删除
        findViewById(R.id.bt_delete).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
//                String sql="delete from user where username='"+etUserName.getText().toString().trim()+"'";
//                db.execSQL(sql);

                String whereClause="username=?";
                String[] whereArgs={etUserName.getText().toString().trim()};
                db.delete("user",whereClause,whereArgs);
                initData();
            }
        });

        //修改
        findViewById(R.id.bt_update).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String sql="update user set password='"+etPassword.getText().toString().trim()+"' where username='"+etUserName.getText().toString().trim()+"'";
                db.execSQL(sql);
                initData();
            }
        });

    }

    //查询
    private void initData(){
        alUser.clear();
        Cursor cursor = db.query("user",null,null,null,null,null,null);//查询并获得游标
        while ((cursor.moveToNext())){
            User user=new User();
            user.username=cursor.getString(cursor.getColumnIndex("username"));
            user.password=cursor.getString(cursor.getColumnIndex("password"));
            alUser.add(user);
        }
        adapter.notifyDataSetChanged();
        etUserName.setText("");
        etUserName.requestFocus();
        etPassword.setText("");
    }

    //隐藏软键盘
    public void hideSoftKeyboard(){
        getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_HIDDEN);
    }
}

package com.example.shen.sqlitetest;

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

/**
 * Created by SHEN on 2015/12/16.
 */
public class DatabaseHelper extends SQLiteOpenHelper {
    private static final String DB_NAME = "mydb.db"; //数据库名称
    private static final int version = 1; //数据库版本
    public DatabaseHelper(Context context) {
        super(context,DB_NAME,null,version);
    }
    @Override
    public void onCreate(SQLiteDatabase db) {
        String sql = "create table user(username varchar(20) not null , password varchar(60) not null );";
        db.execSQL(sql);
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {


    }
}

data/data/<package_name>/databases/

SQLite Developer查看

SQLite demo下载地址：http://download.csdn.net/download/shenyuanqing/9366970

SQLite Developer下载地址：http://download.csdn.net/download/shenyuanqing/9366246