package?helloworld.dongnaoedu.com.imoocsqlitedemo; import?android.database.Cursor; import?android.database.sqlite.SQLiteDatabase; import?android.database.sqlite.SQLiteOpenHelper; import?android.os.Environment; import?android.support.annotation.IdRes; 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.ListView; import?android.widget.RadioGroup; import?android.widget.SimpleCursorAdapter; import?android.widget.Toast; public?class?MainActivity?extends?AppCompatActivity?{ ????private?EditText?nameEdt,ageEdt,idEdt; ????private?RadioGroup?genderGp; ????private?String?genderStr?=?"男"; ????private?SQLiteDatabase?db; ????private?ListView?stuList; ????@Override ????protected?void?onCreate(Bundle?savedInstanceState)?{ ????????super.onCreate(savedInstanceState); ????????setContentView(R.layout.activity_main); ????????//添加操作 ????????//參數(shù)：環(huán)境上下文;數(shù)據(jù)庫名稱(如果只有一個數(shù)據(jù)庫名稱，那么這個數(shù)據(jù)庫的位置會是在私有目錄data中); ????????//?游標(biāo)工廠，通過什么游標(biāo)去操作數(shù)據(jù)，傳null給我一個默認選擇；版本號 ????????//如果帶SD卡路徑，那么數(shù)據(jù)庫位置則在指定的路徑下 ????????//~ ????????String?path?=?Environment.getExternalStorageDirectory()?+?"/stu.db"; ????????SQLiteOpenHelper?helper?=?new?SQLiteOpenHelper(this,path,null,1)?{ ????????????@Override ????????????public?void?onCreate(SQLiteDatabase?db)?{ ????????????????//創(chuàng)建 ????????????????Toast.makeText(MainActivity.this,"數(shù)據(jù)庫創(chuàng)建",Toast.LENGTH_SHORT).show(); ????????????????//如果數(shù)據(jù)庫不存在，則會調(diào)用onCreate方法，那么我們可以將表的創(chuàng)建工作放在這里完成 ????????????????String?sql?=?"create?table?info_db?(_id?integer?primary?key?autoincrement,"?+ ????????????????????????"name?varchar(20),"?+ ????????????????????????"age?integer,"?+ ????????????????????????"gender?varhcar(4))"; ????????????????db.execSQL(sql); ????????????} ????????????@Override ????????????public?void?onUpgrade(SQLiteDatabase?db,?int?oldVersion,?int?newVersion)?{ ????????????????//升級 ????????????????Toast.makeText(MainActivity.this,"數(shù)據(jù)庫升級",Toast.LENGTH_SHORT).show(); ????????????} ????????}; ????????//1、數(shù)據(jù)庫存在則直接打開數(shù)據(jù)庫；（所謂的打開指的是獲得數(shù)據(jù)庫對象） ????????//2、數(shù)據(jù)庫不存在則創(chuàng)建再打開， ????????//3、數(shù)據(jù)庫存在但版本號升高，則調(diào)用升級方法。 ????????db?=?helper.getReadableDatabase();//用于獲取數(shù)據(jù)庫對象 ????????nameEdt?=?(EditText)?findViewById(R.id.name_edt); ????????ageEdt?=?(EditText)?findViewById(R.id.age_edt); ????????idEdt?=?(EditText)?findViewById(R.id.id_edt); ????????genderGp?=?(RadioGroup)?findViewById(R.id.gender_gp); ????????genderGp.setOnCheckedChangeListener(new?RadioGroup.OnCheckedChangeListener()?{ ????????????@Override ????????????public?void?onCheckedChanged(RadioGroup?group,?@IdRes?int?checkedId)?{ ????????????????if(checkedId?==?R.id.male)?{genderStr?=?"男";} ????????????????else{?genderStr?=?"女";} ????????????} ????????}); ????????stuList?=?(ListView)?findViewById(R.id.stu_list); ????} ????public?void?operate(View?v){ ????????String?nameStr?=?nameEdt.getText().toString(); ????????String?ageStr?=?ageEdt.getText().toString(); ????????String?idStr?=?idEdt.getText().toString(); ????????switch?(v.getId()){ ????????????case?R.id.insert_btn: ????????????????//db.rawQuery();??查詢?select?*?from?表名 ????????????????//db.execSQL();???添加，刪除，修改，查找 ????????????????//String?sql?=?"insert?into?info_db(name,age,gender)?values('張',12,'男')"; ????????????????String?sql?=?"insert?into?info_db?(name,age,gender)?values(?,?,?)"; ????????????????db.execSQL(sql,new?String[]{nameStr,ageStr,genderStr}); ????????????????break; ????????????case?R.id.select_btn: //????????????????db.rawQuery(sql) ????????????????//select?*?from?表名?where?_id?=?? ????????????????String?sql2?=?"select?*?from?info_db"; ????????????????if(!idStr.equals("")){ ????????????????????sql2?+=?"?where?_id="?+?idStr; ????????????????} ????????????????//查詢結(jié)果 ????????????????Cursor?c?=?db.rawQuery(sql2,null); ????????????????//SimpleCursorAdapter ????????????????//SimpleAdapter?a?=?new?SimpleAdapter ????????????????//參數(shù)3：數(shù)據(jù)源;4、表頭，即鍵值對；5、要填充的位置;6、通知將變化的數(shù)據(jù)反映到頁面上 ????????????????//數(shù)據(jù)源要有下劃線 ????????????????SimpleCursorAdapter?adapter?=?new?SimpleCursorAdapter(this,R.layout.item, ????????????????????????c,new?String[]{"_id","name","age","gender"}, ????????????????????????new?int[]{R.id.id_item,R.id.name_item,R.id.age_item,R.id.gender_item}); ????????????????stuList.setAdapter(adapter); ????????????????break; ????????????case?R.id.delete_btn: ????????????????Log.d("MainActivity",?"刪除?"); ????????????????String?sql3?=?"delete?from?info_tb?where?_id="+idStr+""; ????????????????db.execSQL(sql3); ????????????????break; ????????????case?R.id.update_btn: ????????????????Log.d("MainActivity",?"更新?"); ????????????????String?sql4?=?"update?info_tb?set?name=?,age=?,gender=??where?_id=?"; ????????????????db.execSQL(sql4,new?String[]{nameStr,ageStr,genderStr,idStr}); ????????????????break; ????????} ????} }