Android(安卓)sqlite本地数据库

做任何开发都会用的数据库， Android 也一样，Android一般都要用的两个数据库本地数据库和远程数据库，本地数据库就是sqlite，远程数据库的话，我一般用的是 MySQL ，这次先了解下本地数据库sqlite，一般数据库类型为varchar(20) 如果你输入个大于20位的数据时，会报错，不能插入吧，但是sqlite里就不一样了，他就可以，这是sqlite的特色之一吧应该是。下来就看看sqlite的crud：

MainActivity

[java] view plain copy

packagecom.example.sqlite;
importandroid.os.Bundle;
importandroid.app.Activity;
importandroid.view.Menu;
importandroid.widget.TextView;
publicclassMainActivityextendsActivity{
@Override
publicvoidonCreate(BundlesavedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
TextViewt;
DBOpenHelterdbopenhelper=newDBOpenHelter(this);
}
@Override
publicbooleanonCreateOptionsMenu(Menumenu){
getMenuInflater().inflate(R.menu.activity_main,menu);
returntrue;
}
}

PersonService

[java] view plain copy

packagecom.example.sqlite;
importcom.example.bean.Person;
importandroid.content.Context;
importandroid.database.Cursor;
importandroid.database.sqlite.SQLiteDatabase;
publicclassPersonService{
privateDBOpenHelterdbOpenHelper;
publicPersonService(Contextcontext){
this.dbOpenHelper=newDBOpenHelter(context);
}
publicvoidsave(Personperson){
SQLiteDatabasedb=dbOpenHelper.getWritableDatabase();
StringBuildersql=newStringBuilder(128);//这个没用
sql.append("insert");//这个没用
db.execSQL("insertintoperson(name,phone)values(?,?)",newObject[]{person.getName(),person.getPhone()});
db.close();
}
publicPersonfind(Integerid){
Personperson=newPerson();
SQLiteDatabasedb=dbOpenHelper.getReadableDatabase();
Cursorcursor=db.rawQuery("select*fromtestpersionwehrename=?",newString[]{id.toString()});
while(cursor.moveToNext()){
intpersonid=cursor.getInt(cursor.getColumnIndex("id"));
}
returnperson;
}
}

DBOpenHelter

package com.example.sqlite;

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteDatabase.CursorFactory;
import android.database.sqlite.SQLiteOpenHelper;

public class DBOpenHelter extends SQLiteOpenHelper{

public DBOpenHelter(Context context) {
super(context, "itcast.db", null, 1);
}

@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL("CREATE TABLE testpersion(persionid integer primary key autoincrement,name varchar(20))");
}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// TODO Auto-generated method stub
db.execSQL("ALTER TABLE testpersion ADD phone VARCHAR(12) NULL");
}

}

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