package com.example.cunli.sqlite002;
import android.content.ContentValues;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.EditText;
import android.widget.LinearLayout;
import android.widget.RadioGroup;
import android.widget.TextView;
import android.widget.Toast;
import java.util.ArrayList;
import java.util.List;
public class MainActivity extends AppCompatActivity {
EditText nameEt,ageEt;
RadioGroup radioGroup;
SQLiteDatabase db;
boolean gender = true;
ContentValues contentValues;
private List<Long> ids = new ArrayList<>();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
contentValues = new ContentValues();
nameEt = (EditText)findViewById(R.id.name);
ageEt = (EditText)findViewById(R.id.age);
radioGroup = (RadioGroup)findViewById(R.id.radioGroup);
radioGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
@Override
public void onCheckedChanged(RadioGroup group, int checkedId) {
if (checkedId == R.id.male){
gender = true;
}else {
gender = false;
}
}
});
//以刻都写的方式打开或创建一个数据
db = openOrCreateDatabase("school",SQLiteDatabase.OPEN_READWRITE,null);
//建表的语句
String createSQL = "CREATE TABLE IF NOT EXISTS Students (_id INTEGER NOT NULL,student_name CHAR(20) NOT NULL,age INTEGER,gender BOOLEAN,PRIMARY KEY(_id))";
//执行建表SQL语句
db.execSQL(createSQL);
}
//点击按钮事件处理
public void saveStudent(View view){
//创建ContentValues
contentValues.put("student_name",nameEt.getText().toString());
contentValues.put("age",Integer.parseInt(ageEt.getText().toString()));
contentValues.put("gender",gender);
//执行插入语句
long id = db.insert("Students",null,contentValues);
ids.add(id);
//如果返回值为-1，则说明那个插入失败
if (id != -1){
Toast.makeText(this,"插入数据成功",Toast.LENGTH_SHORT).show();
}else {
Toast.makeText(this,"插入数据 失败",Toast.LENGTH_SHORT).show();
}
}
@Override
protected void onDestroy() {
super.onDestroy();
if (db!=null){
db.close();//关闭数据库
}
}
// 更新数据库
public void updateStudent(View view){
String updateData = ((EditText)findViewById(R.id.updateData)).getText().toString();
contentValues.put("student_name",updateData);
//更新数据
int num = db.update("Students",contentValues,"_id=?",new String[]{""+1});
Toast.makeText(MainActivity.this,"更新了"+num+"条数据。",Toast.LENGTH_SHORT).show();
}
// 查询数据
public void getData(View view){
LinearLayout linearLayout = (LinearLayout) findViewById(R.id.linerLayout);
linearLayout.removeAllViews();//显示当前数据前，清除之前的数据
Cursor cursor = db.query("Students",new String[]{"student_name","age","gender"},null,null,null,null,"age");
if (cursor.getCount() > 0){
//循环获取数据
while (!cursor.isLast()){//退出循环的条件：是否到cursor的末尾
cursor.moveToNext();//向前移动，注意刚开始的时候，指针是在第一行数据之前的
String name = cursor.getString(0);
int age = cursor.getInt(1);
int gender = cursor.getInt(2);
TextView textView = new TextView(MainActivity.this);
textView.setText(name+":"+age+":"+(gender==1?"男":"女"));
linearLayout.addView(textView);
}
}else {
Toast.makeText(MainActivity.this,"表中没有数据",Toast.LENGTH_SHORT).show();
}
}
// 删除全部数据
public void deleteData(View view){
String[] arr = new String[ids.size()];
for (int i = 0; i < ids.size(); i++) {
int delId = db.delete("Students","_id = ? ",new String[]{ids.get(i).toString()});
Log.e("log","----------------"+delId);
}
Toast.makeText(MainActivity.this,"全部数据已经删除",Toast.LENGTH_SHORT).show();
}
// 清空表中所有数据
public void clearData(View view){
int delId = db.delete("Students",null,null);
Log.e("log","----------------"+delId);
Toast.makeText(MainActivity.this,"表中全部数据已清空",Toast.LENGTH_SHORT).show();
}
}
