【Android】SQLite数据库实例，androidsqlite实例

【Android】SQLite数据库实例，androidsqlite实例

package com.sqlite.sqlite;

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


/**
 * Created by lingyue on 2017/2/9.
 * 希望能做成一个通用的数据库应用模板
 */

public class DatabaseHelper extends SQLiteOpenHelper {

//    数据库名称
    private static final String DB_NAME = "customer.db";
//    表名
    private static final String DB_TABLE = "customer";
//    声明SQLite对象
    private SQLiteDatabase db;
    private static final String DATABASE_CREATE = "create table customer(_id integer primary key autoincrement," +
            "name integer not null," +
            "password integer not null)";

    public DatabaseHelper(Context context){
        super(context,DB_NAME,null,2);
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        this.db = db;
        db.execSQL(DATABASE_CREATE);
    }

//    插入
    public void insert(ContentValues values){
        SQLiteDatabase db = getWritableDatabase();
        db.insert(DB_TABLE, null, values);
        db.close();
    }

//    查询
    public String cheak(String Spassword){
        SQLiteDatabase db = getWritableDatabase();

        Cursor cursor = db.rawQuery("select * from customer", null);

        while ((cursor.moveToNext()) && (!Spassword.equals(cursor.getString(1)))) {

            int _id = cursor.getInt(0); //获取第一列的值,第一列的索引从0开始

            String name = cursor.getString(1);//获取第二列的值

            String password = cursor.getString(2);//获取第三列的值

        }
        if (cursor.isAfterLast()){
            return "error";
        }
        else return cursor.getString(2);

//        cursor.close();
//        db.close();


    }
    public Cursor query(){
        SQLiteDatabase db = getWritableDatabase();
        Cursor cursor = db.query(DB_TABLE,null,null,null,null,null,null);
        return cursor;
    }

//    关闭数据库
    public void close(){
        if (db!=null)
            db.close();
    }
    @Override
    public void onUpgrade(SQLiteDatabase sqLiteDatabase, int i, int i1) {

    }
}