从数据列中查看有多少个以 CC 开头的唯一值(=3)
AB0010
CC0009
AB0010
EF0011
CC1001
AB0090
CC1001
(empty field)
CC1001
CC2001
从...开始:
AB = 2
CC = 3
EF = 1
从数据列中查看有多少个以 CC 开头的唯一值(=3)
AB0010
CC0009
AB0010
EF0011
CC1001
AB0090
CC1001
(empty field)
CC1001
CC2001
从...开始:
AB = 2
CC = 3
EF = 1