Returns the substring of
count occurrences of the delimiter
expr: A STRING or BINARY expression.
delim: An expression matching the type of
exprspecifying the delimiter.
count: An INTEGER expression to count the delimiters.
The result matches the type of
count is positive, everything to the left of the final delimiter (counting from the left) is returned.
count is negative, everything to the right of the final delimiter (counting from the right) is returned.