Using TSQL, can I increment a CHAR(1) column by one and use it in a LEFT OUTER JOIN without a CASE statement?

Question

This question is similar to my last question. Except this time I\'m using letters rather than 6 digit integers. I want to find the out of sequence \"letters\".

Let\

Answer 1

You can convert the char(1) to its ascii number using

ASCII(Letter)

You can then increment this by one and return it to a letter using CHAR (if necessary), so your code would be this:

SELECT * from TABLE1 t1 
LEFT OUTER JOIN TABLE2 t2 
      ON ASCII(t1.INTCol) - 1 = ASCII(t2.INTCol) 
      AND t1.date = t2.date
WHERE t2.id IS NULL

Answer 2

You can use the ASCII() function to convert a character to its ASCII value:

ASCII(Letter)