数据库使用
数据库的创建使用数据库Activity的代码
数据库的创建
package com
.example
.myday1night
;
import org
.greenrobot
.greendao
.annotation
.Entity
;
import org
.greenrobot
.greendao
.annotation
.Id
;
import org
.greenrobot
.greendao
.annotation
.Property
;
import org
.greenrobot
.greendao
.annotation
.Generated
;
@Entity
public class MySQL {
@Id(autoincrement
= true)
private long id
;
@Property(nameInDb
= "name")
private String name
;
@Property(nameInDb
= "price")
private int price
;
@Property(nameInDb
= "count")
private int count
;
@Generated(hash
= 1320634197)
public MySQL(long id
, String name
, int price
, int count
) {
this.id
= id
;
this.name
= name
;
this.price
= price
;
this.count
= count
;
}
@Generated(hash
= 2111380415)
public MySQL() {
}
public long getId() {
return this.id
;
}
public void setId(long id
) {
this.id
= id
;
}
public String
getName() {
return this.name
;
}
public void setName(String name
) {
this.name
= name
;
}
public int getPrice() {
return this.price
;
}
public void setPrice(int price
) {
this.price
= price
;
}
public int getCount() {
return this.count
;
}
public void setCount(int count
) {
this.count
= count
;
}
}
使用数据库Activity的代码
package com
.example
.myday1night
;
import android
.os
.Bundle
;
import android
.view
.View
;
import android
.widget
.Button
;
import android
.widget
.EditText
;
import android
.widget
.Toast
;
import androidx
.appcompat
.app
.AppCompatActivity
;
import androidx
.recyclerview
.widget
.LinearLayoutManager
;
import androidx
.recyclerview
.widget
.RecyclerView
;
import java
.util
.List
;
public class MainActivity extends AppCompatActivity implements View.OnClickListener {
private EditText recy_name
;
private Button recy_insert
;
private RecyclerView recy
;
private Button recy_selete
;
private EditText recy_id
;
private Button quanxuan
;
DaoSession daoSession
;
MySQLDao mySQLDao
;
List
<MySQL> selete
;
@Override
protected void onCreate(Bundle savedInstanceState
) {
super.onCreate(savedInstanceState
);
setContentView(R
.layout
.activity_main
);
initView();
DaoMaster
.DevOpenHelper helper
= new DaoMaster.DevOpenHelper(this, "aaa.db");
DaoMaster daoMaster
= new DaoMaster(helper
.getWritableDb());
daoSession
= daoMaster
.newSession();
mySQLDao
= daoSession
.getMySQLDao();
}
private void initView() {
recy_name
= (EditText
) findViewById(R
.id
.recy_name
);
recy_insert
= (Button
) findViewById(R
.id
.recy_insert
);
recy
= (RecyclerView
) findViewById(R
.id
.recy
);
recy
.setLayoutManager(new LinearLayoutManager(MainActivity
.this));
recy_insert
.setOnClickListener(this);
recy_selete
= (Button
) findViewById(R
.id
.recy_selete
);
recy_selete
.setOnClickListener(this);
recy_id
= (EditText
) findViewById(R
.id
.recy_id
);
recy_id
.setOnClickListener(this);
quanxuan
= (Button
) findViewById(R
.id
.quanxuan
);
quanxuan
.setOnClickListener(this);
}
@Override
public void onClick(View v
) {
switch (v
.getId()) {
case R
.id
.recy_insert
:
MySQL mySQL
= new MySQL(Integer
.parseInt(recy_id
.getText().toString()), recy_name
.getText().toString(), 10000, 0);
insert(mySQL
);
break;
case R
.id
.recy_selete
:
selete
= selete("");
Toast
.makeText(this, "" + selete
.toString(), Toast
.LENGTH_SHORT
).show();
MyAdapter myAdapter
= new MyAdapter(selete
, MainActivity
.this);
recy
.setAdapter(myAdapter
);
break;
case R
.id
.quanxuan
:
break;
}
}
public void insert(MySQL mySQL
) {
mySQLDao
.insert(mySQL
);
}
public List
<MySQL> selete(String name
) {
List
<MySQL> list
= mySQLDao
.queryBuilder().build().list();
return list
;
}
}
