每日打卡

创建数据库

public class MySQLite extends SQLiteOpenHelper { public MySQLite(Context context, String name, SQLiteDatabase.CursorFactory factory, int version) { super(context, name, factory, version);} }

增加数据值

writaDb.execSQL(“insert into 表名 (字段名) values（值）”);\

删除数据

writaDb.execSQL(“delete from 表名 where id=条件值”);

修改数据

writaDb.execSQL(“update 表名 set(字段名) values（值）where id=1”

查找数据

Cursor cursor = writaDb.rawQuery("select t_id from teacher where t_id = “2”, null); while(cursor.moveToNext()){ String name=cursor.getString(cursor.getColumnIndex("Pwd"));}

继承SQLiteOpenHelper重写方法

public class MyDbHelper extends SQLiteOpenHelper { public MyDbHelper(@Nullable Context context) { super(context, "user.db", null, 1); } @Override public void onCreate(SQLiteDatabase db) { db.execSQL("CREATE TABLE userInfo(uid integer PRIMARY KEY autoincrement,uname varchar(8),age INT,sex int,birthday date);"); } @Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { } }