Control Characters

[lesstjm]

I am testing a varchar2 that is about 1000 bytes long. I am trying to check for any control characters(characters that would not be able to be displayed on the screen). Any ideas?

[jmodic]

If by control character you mean characters with ASCII codes between 0 and 31 then the following query will find all records where col1 contains any of such characters:

SELECT * FROM my_tab
WHERE INSTR (TRANSLATE
(
col1,
CHR(1)||CHR(2)||...||CHR(30)||CHR(31),
CHR(0)||CHR(0)||...||CHR(0)||CHR(0)
)
CHR(0)) > 0);

This efectually translates all characters below ASCII code 32 to a character ASCII 0 by using TRANSLATE and then searches for any occurence of such character with ASCII code 0 by using INSTR.