Teradata中的子字符串功能

Question

我需要从字符串'000-111-222-333'中单独提取'000-111'，即Teradata中第二个'-'之前的字符串部分，而无需对位置进行硬编码，因为字符串中的字符数可能会有所不同。预先

Answer 1

Depending on your TD release (or installed UDFs):

SUBSTRING(x FROM 1 FOR INSTR(x,'-',1,2) - 1)

This should work in any TD release:

SUBSTRING(x FROM 1 FOR POSITION('-' IN x) + POSITION('-' IN SUBSTRING(x FROM POSITION('-' IN x) + 1)) - 1)