Use shell to extract and update db2 data

The db2 tutorial I am watching is: use shell to extract and update db2 data. The shell process db2 database program written for work needs uses the shell to extract db2 data and process it.
#SQL Article Definition

SQL="SELECT AAA, BBB, CCC FROM MYTBL1"

#Execute SQL

SDATA=`db2 "$SQL"`

#Return value judgment

if [ $? -ne 0 ]

then

#Show error message returned by db2

echo "$SDATA"

exit 1

fi

# Process the obtained data.

echo "$SDATA" | sed -e '4,/^$/!d;/^$/d' |

while read AAA BBB CCC

do

echo "AAA IS $AAA, BBB IS $BBB, CCC IS $CCC"

done

#get the number of data files

echo "$SDATA" | sed -n -e '/^$/{1,3d;n;s/[^0-9]*\([0-9]*\)[^0-9]*/\1/;p;}' | read CNT

echo "The count of selected data is $CNT."

exit 0★Update db2's data and obtain update results

  SQL="UPDATE MYTBL1 SET AAA='2005',BBB='05',CCC='12'"

#Execute SQL

SDATA=`db2 -a "$SQL"`

#Get SQLCODE

echo "$SDATA" | sed -n -e 's/^.*sqlcode: \([-,0-9][0-9]*\).*/\1/p' | read SQLCODE

echo "Sqlcode is $SQLCODE."

#Get SQLSTATE

echo "$SDATA" | sed -n -e 's/^.*sqlstate: \([-,0-9][0-9]*\).*/\1/p' | read SQLSTATE

echo "Sqlstate is $SQLSTATE."

#Get the number of updates (i.e. the third value of sqlerrd)

echo "$SDATA" | sed -n -e '/sqlerrd/s/^.*(3) \([-,0-9][0-9]*\).*/\1/p' | read UPDCNT

echo "Updated data's count is $UPDCNT."

#Get the fifth value of sqlerrd

echo "$SDATA" | sed -n -e '/sqlerrd/{n;s/^.*(5) \([-,0-9][0-9]*\).*/\1/;p;}' | read SQLERRD5

echo "Sqlerrd(5) is $SQLERRD5."