Android Sqlite SQLiteOpenHelper建立数据库

最新推荐文章于 2023-04-11 19:19:41 发布

haozidao

最新推荐文章于 2023-04-11 19:19:41 发布

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CC 4.0 BY-SA版权

本文链接：https://blog.youkuaiyun.com/haozidao/article/details/51324439

本文介绍了一个用于Android应用的SQLite数据库助手类实现，包括创建数据库、表结构定义、数据增删改查等基本功能。

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

import java.util.ArrayList;
import java.util.HashMap;

/**
 * Created by Administrator on 2016/4/20.
 */
public class DBHelper extends SQLiteOpenHelper{
 final static  int version = 1;
    Cursor cursor;
    SQLiteDatabase db;
    public DBHelper(Context context) {
        super(context, "App.db", null, version);
    }
    @Override
    public void onCreate(SQLiteDatabase db) {

//建表
        String CREATE_TABLE_GT = "create table if not exists temp (id INTEGER PRIMARY KEY AUTOINCREMENT,key varchar)";
        //购物车
         String DB_GOUWUCHE="create table if not exists gouwuche ( id INTEGER PRIMARY KEY AUTOINCREMENT,shopid text," +
                 "attoneid text,atttwoid text,merchantid text,name text," +
                "price text,img text,count text,shuxin1,shuxin2)";
        db.execSQL(CREATE_TABLE_GT);
        db.execSQL(DB_GOUWUCHE);


    }

//添加
    public void add(){
        db = this.getWritableDatabase();
        db.execSQL("insert into temp (key) values('aa')");
        cursor =  db.rawQuery("select * from temp",new String[]{});
        if (cursor.moveToNext()){
            String key= cursor.getString(cursor.getColumnIndex("key"));
            int id = cursor.getInt(cursor.getColumnIndex("id"));
        }
    }
    //查询
    public void query(String sql){
        db = getReadableDatabase();
        cursor= db.rawQuery(sql,new String[]{});
        //
        cursor.close();
    }
    //增加，删除修改
    public boolean idu(String sql){
        boolean result = true;
        try {
            db.execSQL(sql);
        }catch (SQLException e){
            result = false;
        }
        return result;

    }
    public void close(){
        if (cursor!=null){
            cursor.close();
        }
        if (db!=null&&db.isOpen()){
            db.close();
        }

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

    }
    public ArrayList<String> getAll() {
        db = this.getReadableDatabase();
        String sql = "select * from temp";
        cursor = db.rawQuery(sql,new String[]{});
        ArrayList<String> list = new  ArrayList<String>();
        while (cursor.moveToNext()) {


            String key= cursor.getString(cursor.getColumnIndex("key"));
            int id = cursor.getInt(cursor.getColumnIndex("id"));
            list.add(key);

        }
        return list;
    }
    public ArrayList<Integer> getId() {
        db = this.getReadableDatabase();
        String sql = "select * from temp";
        cursor = db.rawQuery(sql,new String[]{});
        ArrayList<Integer> list = new  ArrayList<Integer>();
        while (cursor.moveToNext()) {


            String key= cursor.getString(cursor.getColumnIndex("key"));
            int id = cursor.getInt(cursor.getColumnIndex("id"));
            list.add(id);

        }
        return list;
    }

    /**
     * 向表格temp中添加数据
     *
     * @param act
     */
    public void insertAction(String act) throws Exception {
        db = this.getWritableDatabase();
        if (act != null) {
            if(act.length()<1){
                return;
            }

            String isql = "insert into temp(key) values(?)";
            db.execSQL(isql, new Object[] {act});

        } else {

        }
    }
//购物车添加数据
    public void addShoping(HashMap<String,String> map){

        db = this.getWritableDatabase();
        if (map != null) {
            if(map.size()<1){
                return;
            }

            cursor= db.query("gouwuche", new String[] { "shopid", "attoneid",
                    "atttwoid", "merchantid" }, "shopid"+"=? and "+"attoneid"+"=? and "+"atttwoid"+"=? and "+"merchantid"+"=?", new String[]{map.get("shopid"),map.get("attoneid"),map.get("atttwoid"),map.get("merchantid")}, null,null,null,null);
        boolean boo=true;
               while (cursor.moveToNext()) {
                   ContentValues values = new ContentValues();
                   values.put("count",map.get("count"));//key为字段名，value为值
                   db.update("gouwuche", values, "shopid=?", new String[]{map.get("shopid")});
                   boo=false;
               }
           if(boo){
               String isql = "insert into gouwuche (shopid,attoneid,atttwoid,merchantid,name,price,img,count,shuxin1,shuxin2) values(?,?,?,?,?,?,?,?,?,?)";
               db.execSQL(isql, new Object[] {map.get("shopid"),map.get("attoneid"),map.get("atttwoid"),map.get("merchantid"),map.get("name")
                       ,map.get("price"),map.get("img"),map.get("count"),map.get("shuxin1"),map.get("shuxin2")});

           }



        } else {

        }
    }
    //根据商品id删除购物车中的数据
    public boolean deleteShoping(String id,String attoneid,String atttwoid) throws Exception {
        db = this.getWritableDatabase();


        // 系统指令不能删除
        String dsql = "delete from gouwuche where shopid ="+id+" and attoneid ="+attoneid+" and atttwoid ="+atttwoid;
        db.execSQL(dsql);

        return true;

    }
    //修改购物车商品
    public int upDataShong(HashMap<String,String> map){
        db = this.getWritableDatabase();
        ContentValues values = new ContentValues();

        values.put("shopid", map.get("shopid"));
        values.put("attoneid", map.get("attoneid"));
        values.put("atttwoid", map.get("atttwoid"));
        values.put("merchantid", map.get("merchantid"));
        values.put("name", map.get("name"));
        values.put("price", map.get("price"));
        values.put("img", map.get("img"));
        values.put("count", map.get("count"));
        values.put("shuxin1", map.get("shuxin1"));
        values.put("shuxin2", map.get("shuxin2"));
        String shopid=map.get("shopid");
        return db.update("gouwuche", values,"shopid="+ shopid, null);
    }
//查询购物车所有物品
    public ArrayList<HashMap<String,String>> getAllShoping() {
        db = this.getReadableDatabase();
        String sql = "select * from gouwuche";
        cursor = db.rawQuery(sql,new String[]{});
        ArrayList<HashMap<String,String>> list = new  ArrayList<HashMap<String,String>>();
        while (cursor.moveToNext()) {

            HashMap<String,String> map=new HashMap<>();


            String shopid= cursor.getString(cursor.getColumnIndex("shopid"));
            String attoneid= cursor.getString(cursor.getColumnIndex("attoneid"));
            String atttwoid= cursor.getString(cursor.getColumnIndex("atttwoid"));
            String merchantid= cursor.getString(cursor.getColumnIndex("merchantid"));
            String name= cursor.getString(cursor.getColumnIndex("name"));
            String price= cursor.getString(cursor.getColumnIndex("price"));
            String img= cursor.getString(cursor.getColumnIndex("img"));
            String count= cursor.getString(cursor.getColumnIndex("count"));
            String shuxin1= cursor.getString(cursor.getColumnIndex("shuxin1"));
            String shuxin2= cursor.getString(cursor.getColumnIndex("shuxin2"));
            map.put("shopid",shopid);
            map.put("attoneid",attoneid);
            map.put("atttwoid",atttwoid);
            map.put("merchantid",merchantid);
            map.put("name",name);
            map.put("price",price);
            map.put("img",img);
            map.put("count",count);
            map.put("shuxin1",shuxin1);
            map.put("shuxin2",shuxin2);

            list.add(map);

        }
        return list;
    }


    /**
     * 删除指令
     */
    public boolean deleteAction(int id) throws Exception {
        db = this.getWritableDatabase();


            // 系统指令不能删除
            String dsql = "delete from temp where id ="+id;
            db.execSQL(dsql);

            return true;

    }
    public boolean deleteAll() throws Exception {
        db = this.getWritableDatabase();


        // 系统指令不能删除
        String dsql = "delete from temp where 1 = 1";
        db.execSQL(dsql);

        return true;

    }

}