在sqlite中计算一个列中的多项？

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例如：

id columnA 1 black 2 red 3 red 4 绿色 5 red 6 black 7 白色

我想要计算黑色和红色项目的总数。结果应为5。 此代码工作正常，但如果我尝试添加红色则无效。 long count = DatabaseUtils.longForQuery（db， SELECT COUNT（*）FROM mytable WHERE columnA =' + black + '，null）;

对不起，我的英文不好，谢谢你的帮助... 我尝试了什么： long count = DatabaseUtils.longForQuery（db，SELECT COUNT（*）FROM mytable WHERE columnA =（'+black+'AND'+ red+），null）;

解决方案

SELECT somecolumn，someothercolumn，COUNT（*） FROM my_table GROUP BY somecolumn，someothercolumn SQLite：count函数 [ ^ ]

select type ，count（ type ）来自 表 组 按 型;

For example :

id columnA 1 black 2 red 3 red 4 green 5 red 6 black 7 white

I want to count total of "black" and "red" items. Result should be "5". This code work fine, but if I try to add "red" it's not working.

long count = DatabaseUtils.longForQuery(db, "SELECT COUNT(*) FROM mytable WHERE columnA = '" + "black" + "', null);

Sorry my bad English, thanks for helping... What I have tried: long count = DatabaseUtils.longForQuery(db, "SELECT COUNT(*) FROM mytable WHERE columnA = ('" + "black" + "' AND '" + "red" + "'"), null);

解决方案

SELECT somecolumn,someothercolumn, COUNT(*) FROM my_table GROUP BY somecolumn,someothercolumn SQLite: count Function[^]

select type, count(type) from table group by type;