SAP BODS SCRIPT - COUNT of Records from 2 HANA Tables and Calculate Difference

I am trying to calculate difference between the count of records using the below script and receiving warning during validation. But No issue with output

$source_count = sql('DATASTORE','select count(*) from Source Table');<br>$filter1_count = sql('DATASTORE','select count(*) from Target Table' || 'where colmn1 in (\'0,00\',\'0\') ');<br>$diff_count = $source_count - $filter1_count ;<br>print( '# ESTIMATED TOTAL RECORDS AFTER CLEANING :' ||$diff_count);

BODS Warning

[Script:Script_Count] Warning: Expression <($$source_count - $filter1_count)> of type <REAL> will be converted to type <VARCHAR>. (BODI-1110432)

Tried adding cast($diff_count,'varchar(10)'); before printing the value. but no use of it. need suggestions to avoid warning.

Note: All are global variables - declared as VARCHAR - 10