public class ContentPriver extends ContentProvider{private static final String AUTHORITY = "com.example.dell_pc.day10_19_contentprovider.student.db";private static final int USER_CODE = 6;//定义数据库对应的编码private static UriMatcher uriMatcher;{uriMatcher = new UriMatcher(uriMatcher.NO_MATCH);uriMatcher.addURI(AUTHORITY,"user",USER_CODE);}private SQLiteHopen myOpenHelper;SQLiteDatabase db;//在创建时被调用@Overridepublic boolean onCreate() {myOpenHelper = new SQLiteHopen(getContext());db = myOpenHelper.getWritableDatabase();return false;}@Nullable@Override//根据Uri查询出selction指定的条件所匹配的全部记录，并且可以指定查询哪些列以什么样的方式order（）排序public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder) {Cursor cursor = db.query("student",projection,selection,selectionArgs,null,null,sortOrder,null);return cursor;}@Nullable@Override//返回当前Uri的MiME类型，如果该URI对应的数据可能包括对跳记录//那么这个MIME类型字符串 就是以vnd.android.dir/开头// 如果该URI对应的数据只有一条记录该MIME类型字符串 就是以vnd.android.cursor.item开头public String getType(Uri uri) {return null;}//根据Uri插入Values对应的数据@Nullable@Override//uri:内容提供者的主机名public Uri insert(Uri uri, ContentValues values) {db.insert("student",null,values);return uri;}根据Uri删除selection指定的调价所匹配的全部记录@Overridepublic int delete(Uri uri, String selection, String[] selectionArgs) {int i = db.delete("student",selection,selectionArgs);return i;}@Override//根据Uri修改selection指定的条件所匹配的全部记录public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {int i = db.update("student",values,selection,selectionArgs);return i;}}
