返回冒号左侧的字符

Question

是否可以返回冒号（:)左侧的所有字符？

当前返回：

 J441:CHRONICOBSTRUCTIVEPULMONARYDISEASEW
O80:ENCOUNTERFORFULL-TERMUNCOMPLICATEDDE
I7389:OTHERSPECIFIEDPERIPHERALVASCULARDI

我想返回J441，O80和I7389。

谢谢。

Answer 1

SELECT NVL(SUBSTR('J441:CHRONICOBSTRUCTIVEPULMONARYDISEASEW', 0, INSTR('J441:CHRONICOBSTRUCTIVEPULMONARYDISEASEW', ':')-1), 'J441:CHRONICOBSTRUCTIVEPULMONARYDISEASEW') AS output
  FROM DUAL

返回J441

with t1 as
(
select 'J441:CHRONICOBSTRUCTIVEPULMONARYDISEASEW' as col from dual
union all
select 'O80:ENCOUNTERFORFULL-TERMUNCOMPLICATEDDE' from dual
union all
select 'I7389:OTHERSPECIFIEDPERIPHERALVASCULARDI' from dual

)  SELECT NVL(SUBSTR(col, 0, INSTR(col, ':')-1), col) AS output
  FROM t1