While investigating a possible bug, I ran the following two queries using the SAP ADO Provider:
SELECT NAME1, LAND1, KUNNR from KNA1 where (NAME1 LIKE 'Dan%' AND LAND1 Like 'D%')
SELECT NAME1, LAND1, KUNNR from KNA1 where (NAME1 LIKE 'Dan%' AND LAND1 Like 'd%')
(NOTE - the casing of the last value was modified).
The results returned varied. Actually, the first query returned some rows, while the second didn't. Digging deeper, here's what I found - Character comparisons in SAP are case sensitive
On top of that, all columns in SAP tables cannot store mixed-case characters. Some can, while others can only store UPPERCASE characters.
Here's how you can figure out whether a column in a table can store only uppercase, or both upper and lower case characters ..