一個小問題：在查詢中如何判斷一字段前13位中是否包含某一字符？

Question

select instr('ASJFKAL---AJS','K') from dual;

Answer 1

select col_name like '%substr(col_name,1,13)%' from dual;

Answer 2

SQL> select decode(instr(substr('ASJFKAL---AJSKLDFUAIOSDF',1,13),'K'),0,'none','has') from dual;DECODE(INSTR(SUBSTR('ASJFKAL--
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hasSQL> select decode(instr(substr('ASJFKAL---AJSKLDFUAIOSDF',1,13),'D'),0,'none','has') from dual;DECODE(INSTR(SUBSTR('ASJFKAL--
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none

Answer 3

SELECT COLUMN_NAME
FROM TABLE_NAME
WHERE SUBSTR(COLUMN_NAME,1,13) LIKE '%K%'