/**
* @param tableName
* @param projectionIn 需要返回的字段，null返回所有字段
* @param selection where语句, 不包含where关键字，eg id=? and age=?
* @param selectionArgs 对应where语句?的值 new String[]{String.valueOf(id), String.valueOf(age)}
* @param groupBy
* @param having
* @param sortOrder 升序降序 id desc
* @param limit 返回结果的数目
* @return
*/
protected Cursor query(
String tableName,
String[] projectionIn,
String selection,
String[] selectionArgs,
String groupBy,
String having,
String sortOrder,
String limit) {
SQLiteQueryBuilder builder = new SQLiteQueryBuilder();
builder.setTables(tableName);
Cursor cursor =
builder.query(
mDbHelper.getReadableDatabase(),
projectionIn,
selection,
selectionArgs,
groupBy,
having,
sortOrder,
limit);
return cursor;
}
protected Cursor rawQuery(String sql, String[] args) {
Cursor cursor = mDbHelper.getReadableDatabase().rawQuery(sql, args);
if (cursor == null) {
return null;
} else if (!cursor.moveToFirst()) {
cursor.close();
return null;
}
return cursor;
}
protected Cursor query(
String tableName,
@Nullable String selection,
@Nullable String[] selectionArgs,
@Nullable String[] columns) {
SQLiteQueryBuilder builder = new SQLiteQueryBuilder();
builder.setTables(tableName);
Cursor cursor =
builder.query(
mDbHelper.getReadableDatabase(), columns, selection, selectionArgs, null, null, null);
return cursor;
}
protected long insert(String tableName, ContentValues cv) {
SQLiteDatabase db = mDbHelper.getReadableDatabase();
return db.insert(tableName, null, cv);
}
public int update(String table, ContentValues values, String whereClause, String[] whereArgs) {
SQLiteDatabase db = mDbHelper.getReadableDatabase();
return db.update(table, values, whereClause, whereArgs);
}
public int delete(String tableName, String whereClause, String[] whereArgs) {
SQLiteDatabase db = mDbHelper.getReadableDatabase();
int deleted = db.delete(tableName, whereClause, whereArgs);
return deleted;
}