Replacing variable values in defined string through awk / xargs - unix

Question

We are dynamically generating a string in bash to insert data in oracle database. The string is like
> echo $str1
insert into tbl select '$jobid','$1','$2','$3','$sdate' from dual ;
Here the variables $1,$2 ... are dynamic and can go upto 10
Now we have data in a file with same number of ':' separated datacolumns as there are numeric variables ( $1,$2.. ) in above string.
Challenge here is to have $1 replaced with 1st column of data, $2 with 2nd column and so on. This needs to be done for all rows of dataset and a separate file needs to be generated with "insert" string as base and with replaced data from the file.
For e.g the sample data
cat test.dat
ONLINE:odr1_redo_06a.log:NO
ONLINE:odr1_redo_06b.log:NO
ONLINE:odr1_redo_05a.log:NO
and the string is
echo $str1
insert into tbl select '$jobid','$1','$2','$3','$sdate' from dual ;
Required output should be
insert into tbl select '$jobid','ONLINE','odr1_redo_06a.log','NO','$sdate' from dual ;
insert into tbl select '$jobid','ONLINE','odr1_redo_06b.log','NO','$sdate' from dual ;
insert into tbl select '$jobid','ONLINE','odr1_redo_05a.log','NO','$sdate' from dual ;
Tried using string as external variable in awk. No luck
cat test.dat | awk -F: -v var="$str1" '{print var}'
insert into tbl select '$jobid','$1','$2','$3','$sdate' from dual ;
insert into tbl select '$jobid','$1','$2','$3','$sdate' from dual ;
insert into tbl select '$jobid','$1','$2','$3','$sdate' from dual ;
or xargs
sed 's/:/ /g' test.dat | xargs -n3 bash -c "echo $str1"
insert into tbl select $jobid,$1,$2,$3,$sdate from dual
insert into tbl select $jobid,$1,$2,$3,$sdate from dual
insert into tbl select $jobid,$1,$2,$3,$sdate from dual
Writing a small loop and calling line by line bears overhead so don't prefer doing that. Any ideas how this can be done in optimal fashion ?

Answer 1

With Awk, for each record, replace every literal $n with the value of nth field in your template by means of gsub function and print the result.
awk -F: -v tmpl="$str1" '{
out = tmpl
for (i=1; i<=NF; i++)
gsub(("\\$" i), $i, out)
print out
}' file
Proof of concept:
$ str1="insert into tbl select '\$jobid','\$1','\$2','\$3','\$sdate' from dual ;"
$
$ awk -F: -v tmpl="$str1" '{
> out = tmpl
> for (i=1; i<=NF; i++)
> gsub(("\\$" i), $i, out)
> print out
> }' file
insert into tbl select '$jobid','ONLINE','odr1_redo_06a.log','NO','$sdate' from dual ;
insert into tbl select '$jobid','ONLINE','odr1_redo_06b.log','NO','$sdate' from dual ;
insert into tbl select '$jobid','ONLINE','odr1_redo_05a.log','NO','$sdate' from dual ;