Shell Programming and Scripting

A for after
grep -A 3 print three lines

start=1;
grep -n ^$ file | sed s/:// | while read lineno
do
end=$lineno;
cat file | sed -n "$start,$end p" | grep -m 1 Enter
cat file | sed -n "$start,$end p" | grep -m 1 "SQL RUN"
cat file | sed -n "$start,$end p" | grep -m 1 '@'
start=$end
done

i think this may help you. this not efficient method.
the logic is
print lines between two blank lines and grep first occerence of "Enter" , grep first occerence of "SQL RUN" and grep first occerence of "@"

or try this
start=1;
grep -n ^$ file | sed s/:// | while read lineno
do
end=$lineno;
cat file | sed -n "$start,$end p" | egrep -m 3 'Enter|SQL RUN|@'
start=$end
done