随手记(二)
MySQLiteHelper.java
public class MySQLiteHelper extends SQLiteOpenHelper {
//抽象类必须调用父类方法
public MySQLiteHelper(Context context, String name, CursorFactory factory, int version) {
//调用父类构造函数
super(context, getMyDatabaseName(name), factory, version);
}
private static String getMyDatabaseName(String name){
String databasename = name;
boolean isSdcardEnable = false;
String state = Environment.getExternalStorageState();
if(Environment.MEDIA_MOUNTED.equals(state)){//SDCard是否插入
isSdcardEnable = true;
}
String dbPath = null;
if(isSdcardEnable){
dbPath = Environment.getExternalStorageDirectory().getAbsolutePath() + "/Finance/database/";
}else{//未插入SDCard,建在内存中
}
File dbp = new File(dbPath);
if(!dbp.exists()){
dbp.mkdirs();
}
databasename = dbPath + databasename;
return databasename;
}
/**
* 当数据库首次创建时执行该方法,一般将创建表等初始化操作放在该方法中执行.
* 重写onCreate方法,调用execSQL方法创建表
*/
@Override
public void onCreate(SQLiteDatabase db) {
Log.i("SWORD", "create a Database");
//创建数据库sql语句
String sql = "create table finance(ID integer PRIMARY KEY AUTOINCREMENT,Type varchar(10),Time varchar(20),Fee double,Remarks varchar(20),Budget varchar(10))";
//执行创建数据库操作
db.execSQL(sql);
//创建表
sql = "create table plan(ID integer PRIMARY KEY AUTOINCREMENT,Morningplan varchar(100),Afternoonplan varchar(100),Nightplan varchar(100),Rank varchar(5), Conclusion varchar(100))";
//执行创建数据库操作
db.execSQL(sql);
}
@Override
//当打开数据库时传入的版本号与当前的版本号不同时会调用该方法
public void onUpgrade(SQLiteDatabase sqLiteDatabase, int i, int i1) {
}
}