Android笔记（四十三） Android中的数据存储——SQLite（五）delete

package cn.lixyz.sqlite;

import android.app.Activity;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteDatabase.CursorFactory;
import android.database.sqlite.SQLiteOpenHelper;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class MainActivity extends Activity {

private EditText name, age, paramter, originalAge, newAge, deleteAge;
private Button insertButton, selectButton, paramterSelect, updateButton, deleteButton;

private SQLiteDatabase database;
private MySQLiteOpenHelper msop;

public String inputSex;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

findView();

msop = new MySQLiteOpenHelper(this, "user.db", null, 1);
database = msop.getReadableDatabase();

}

private void findView() {
name = (EditText) findViewById(R.id.name);
age = (EditText) findViewById(R.id.age);
insertButton = (Button) findViewById(R.id.insertButton);
selectButton = (Button) findViewById(R.id.selectButton);
paramter = (EditText) findViewById(R.id.paramter);
paramterSelect = (Button) findViewById(R.id.paramterSelect);
originalAge = (EditText) findViewById(R.id.originalAge);
newAge = (EditText) findViewById(R.id.newAge);
updateButton = (Button) findViewById(R.id.updateButton);
deleteAge = (EditText) findViewById(R.id.deleteAge);
deleteButton = (Button) findViewById(R.id.deleteButton);
}

public void clickButton(View view) {
switch (view.getId()) {
case R.id.selectButton:
selectData();
break;

case R.id.insertButton:
insertData();
break;
case R.id.paramterSelect:
paramterSelect();
break;
case R.id.updateButton:
updateData();
break;
case R.id.deleteButton:
deleteData();
}
}

private void deleteData() {
String str = deleteAge.getText().toString();
String whereClause = "age = ?";
String[] whereArgs = new String[] { str };

int i = database.delete("user", whereClause, whereArgs);
if (i > 0) {
Toast.makeText(MainActivity.this, "删除成功", Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(MainActivity.this, "删除不成功", Toast.LENGTH_SHORT).show();
}

}

private void updateData() {
String oldAge = originalAge.getText().toString();
String updateAge = newAge.getText().toString();
ContentValues cv = new ContentValues();
cv.put("age", updateAge);
String whereColumn = "age=?";// 修改条件
String[] whereArgs = { oldAge };
int i = database.update("user", cv, whereColumn, whereArgs);
if (1 > 0) {
Toast.makeText(MainActivity.this, "更新成功", Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(MainActivity.this, "更新不成功", Toast.LENGTH_SHORT).show();
}
}

private void paramterSelect() {
String inputAge = paramter.getText().toString();
Cursor c = database.rawQuery("select * from user where age>?", new String[] { inputAge });
if (c.moveToFirst()) {
do {
int id = c.getInt(c.getColumnIndex("id"));
String name = c.getString(c.getColumnIndex("name"));
String age = c.getString(c.getColumnIndex("age"));
Log.d("TTTT", "id=" + id + ",name=" + name + ",age=" + age);
} while (c.moveToNext());
}
c.close();

}

private void insertData() {
String inputAge = age.getText().toString();
String inputName = name.getText().toString();
ContentValues cv = new ContentValues();
cv.put("name", inputName);
cv.put("age", inputAge);
database.insert("user", null, cv);
Toast.makeText(MainActivity.this, "插入成功", Toast.LENGTH_SHORT).show();
age.setText("");
name.setText("");

}

private void selectData() {
Cursor c = database.query("user", null, null, null, null, null, null);
if (c.moveToFirst()) {
do {
int id = c.getInt(c.getColumnIndex("id"));
String name = c.getString(c.getColumnIndex("name"));
String age = c.getString(c.getColumnIndex("age"));
Log.d("TTTT", "id=" + id + ",姓名=" + name + ",年龄=" + age);
} while (c.moveToNext());
}
c.close();

}

class MySQLiteOpenHelper extends SQLiteOpenHelper {

private static final String CREATE_USER = "create table user(id integer primary key autoincrement,name text,age text)";

private Context mContext;

public MySQLiteOpenHelper(Context context, String name, CursorFactory factory, int version) {
super(context, name, factory, version);
mContext = context;
}

@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL(CREATE_USER);
}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// TODO Auto-generated method stub

}

}
}

<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent" >

<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context=".MainActivity" >

<EditText
android:id="@+id/name"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="输入姓名" />

<EditText
android:id="@+id/age"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="输入年龄" />

<Button
android:id="@+id/insertButton"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:onClick="clickButton"
android:text="点击插入" />

<Button
android:id="@+id/selectButton"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:onClick="clickButton"
android:text="点击查询" />

<TextView
android:id="@+id/text"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="条件搜索" />

<EditText
android:id="@+id/paramter"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="您要搜多少岁以上的？" />

<Button
android:id="@+id/paramterSelect"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:onClick="clickButton"
android:text="点击搜索" />

<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="update" />

<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal" >

<EditText
android:id="@+id/originalAge"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:hint="要修改的年龄" />

<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="修改为" />

<EditText
android:id="@+id/newAge"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:hint="新年龄" />
</LinearLayout>

<Button
android:id="@+id/updateButton"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:onClick="clickButton"
android:text="UPDATE" />

<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="删除数据" />

<EditText
android:id="@+id/deleteAge"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="您要删除的年龄" />

<Button
android:id="@+id/deleteButton"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:onClick="clickButton"
android:text="点击删除" />
</LinearLayout>

</ScrollView>