比较q kdb中表的两个字符串列的值

Question

我们有一张桌子：

q)t:([] a:("abc";"def";"ghi";"lmn"); b:("abc";"xyz";"ghi";"def"); c:1 2 3 4)
q)t
a     b     c
-------------
"abc" "abc" 1
"def" "xyz" 2
"ghi" "ghi" 3
"lmn" "def" 4

预期输出：将a列和b列按行匹配，并相应地更新mu列

a     b     c mu
---------------------
"abc" "abc" 1 match
"def" "xyz" 2 unmatch
"ghi" "ghi" 3 match
"lmn" "def" 4 unmatch

当我在查询下面运行时，输出失败

q)select a,b,c, mu:?[any a like/: b; `match; `unmatch] from t
a     b     c mu
---------------------
"abc" "abc" 1 match
"def" "xyz" 2 match // Issue here, since match a value of column a in all value of b
"ghi" "ghi" 3 match
"lmn" "def" 4 unmatch

Answer 1

如果您希望进行逐行匹配，则可以使用match运算符（〜）和each-both运算符（'）。

 q) update  mu:?[a~'b;`match;`unmatch] from t