Question

如何使这条线工作？

return ourDatabase.rawQuery("SELECT * FROM GL_" + tablename + " WHERE " + KEY_GROUP_T + " = " + grp + " ORDER BY " + KEY_NAME_T + " COLLATE NOCASE", null);

04-23 17：58：26.701：E / AndroidRuntime（9212）：引起： android.database.sqlite.SQLiteException：没有这样的列：Baked_Goods：，同时编译：SELECT * FROM GL_table4 WHERE grlist_group = Baked_Goods ORDER BY grlist_name COLLATE NOCASE

这一行正在运行，但我想用rawQuery做到这一点：

return ourDatabase.query("GL_" + tablename, columns, KEY_GROUP_T + "= ?" , new String[]{grp}, null, null, null);

Answer 1

要使其工作，您必须在字符串周围放置单引号。例如：

return ourDatabase.rawQuery("SELECT * FROM GL_" + tablename + " WHERE " + KEY_GROUP_T + " = '" + grp + "' ORDER BY " + KEY_NAME_T + " COLLATE NOCASE", null);

<强>加成

如果从用户的输入中获取grp，Waqas有一个好点，他正在阻止SQL insertion attack。如果你总是定义grp，那么这不是关键但是很好的做法。

Answer 2

改变这个：

return ourDatabase.rawQuery("SELECT * FROM GL_" + tablename + " WHERE " +
KEY_GROUP_T + " = " + grp + " ORDER BY " + KEY_NAME_T + " COLLATE NOCASE", null);

对此：

return ourDatabase.rawQuery("SELECT * FROM GL_" + tablename + " WHERE " +
KEY_GROUP_T + " = ? ORDER BY " + KEY_NAME_T + " COLLATE NOCASE", new String[]{grp});

Answer 3

虽然单引号方法是正确的，但您可以提高查询速度，并提供更好的可读性，如果您这样做，也不能忘记单引号：

String [] selectionArgs = {String.valueOf(grp)};
ourDatabase.rawQuery("SELECT * FROM GL_" + tablename + " WHERE " + KEY_GROUP_T + " = ?" + " ORDER BY " + KEY_NAME_T + " COLLATE NOCASE", selectionArgs);

Android sqlite where子句

3 个答案: