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Problem while passing variable

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# 1  
Old 11-22-2010
Problem while passing variable
Within a shell im starting a terdata BTEQ session

Code:
#!/bin/ksh
set -x
 
TEMP_DATABASE=`head -6 /home/karthik/para.txt|tail -1`
TEMP_TABLE=`head -7 /home/karthik/para.txt|tail -1`
 
bteq<<EOF
.LOGON TEST/karthik,********;
.EXPORT FILE=test1.txt;
.set heading ''
.set titledashes off; 
.set width 1300;
SELECT COUNT(*) FROM ${TEMP_DATABASE}.${TEMP_TABLE};
.EXPORT RESET;
.QUIT;
.exit;
EOF

When I running this, its gives result as expected. That is my shell variable passing into BTEQ session.

I’m storing my actual into a file SQL.txt

My file contains following SQL

Code:
SELECT COUNT(*) FROM ${TEMP_DATABASE}.${TEMP_TABLE};

Again im rewriting my BTEQ script as follows


Code:
#!/bin/ksh
set -x
 
TEMP_DATABASE=`head -6 /home/karthik/para.txt|tail -1`
TEMP_TABLE=`head -7 /home/karthik/para.txt|tail -1`
 
bteq<<EOF
.LOGON TEST/karthik,********;
.EXPORT FILE=test1.txt;
.set heading ''
.set titledashes off; 
.set width 1300;
.run file /home/karthik/SQL.txt;
.EXPORT RESET;
.QUIT;
.exit;
EOF

Here my shell variable is not passing into my SQL stored in the file. Hence my script is not running

please help me out
Last edited by pludi; 11-22-2010 at 08:01 AM.. Reason: code tags, please...
# 2  
Old 11-22-2010
Shell parameter substitution does not take place in data files.
You will need to process the line in Shell if you want Shell to perform the substitution.
For example:

Code:
#!/bin/ksh
set -x
 
TEMP_DATABASE=`head -6 /home/karthik/para.txt|tail -1`
TEMP_TABLE=`head -7 /home/karthik/para.txt|tail -1`
echo "SELECT COUNT(*) FROM ${TEMP_DATABASE}.${TEMP_TABLE};" >/home/karthik/SQL.txt

There are other alternatives, such as:
1) Read the environment variables with the SQL progam. I don't know how to do this in your SQL but most database languages offer this.
2) Use sed or ed to change the SQL.txt file.
3) Use a SQL program to change the SQL.txt file.
# 3  
Old 11-22-2010
actually i dont want to use my SQL with in the shell....coz my SQL may contains more than 500 lines....so i want to store it in a file and need to run...moreover i dont want to edit the shell(editing SQL in shell) each time when Requirement changes....rather i can change the SQL stored in a file

FYI: im using teradata DB
# 4  
Old 11-22-2010
The reason is that the parsing process in the shell runs in steps: in one steps all the parameters are expanded, in one step all the files are being read, etc. This is why you can have a "here-document" containing variables (which will be expanded to there values), but not a file containing variables.

You have several options, but probably the easiest one to maintain is: you could parse (this is: replace the variables with their content) your file ( /home/karthik/SQL.txt, if I'm correct) yourself prior to reading it. If you have a file with variable definitions (i called it "some_declaration_file") of the form

Code:
var1=value1
var2=value2
var3=value3
...

You could do the following:

Code:
#!/bin/ksh
set -x

TEMP_DATABASE=`head -6 /home/karthik/para.txt|tail -1`
TEMP_TABLE=`head -7 /home/karthik/para.txt|tail -1`

cp /home/karthik/SQL.txt /tmp/parsefile
cat some_declaration_file |\
while read line ; do
     varname=${line%%=*}
     varcontent=${line##*=}

     sed 's/\${'"$varname"'}/'"$varcontent"'/g'  /tmp/parsefile > /tmp/parsefile.tmp
     mv /tmp/parsefile.tmp /tmp/parsefile
done

bteq<<EOF
.LOGON TEST/karthik,********;
.EXPORT FILE=test1.txt;
.set heading ''
.set titledashes off; 
.set width 1300;
.run file /tmp/parsefile;
.EXPORT RESET;
.QUIT;
.exit;
EOF

Actually the "sed"-statement changes "${variable}" to "content_of_variable" if in the declaration file there is a line

Code:
variable=content_of_variable

Instead of reading this declaration file completely line by line (as i have done with the while-loop) you could also limit your replacement to several lines of this declaration file.

I hope this helps.

bakunin
Last edited by bakunin; 11-22-2010 at 09:07 AM..
# 5  
Old 11-22-2010
Code:
 
#!/bin/ksh
set -x
TEMP_DATABASE=`head -6 /home/karthik/para.txt|tail -1`
TEMP_TABLE=`head -7 /home/karthik/para.txt|tail -1`
cp /home/karthik/SQL.txt /home/karthik/parsefile
cat some_declaration_file |\
while read line ; do
varname=${line%%=*}
varcontent=${line##*=}
sed 's/\${'"$varname"'}/'"$varcontent"'/g' /tmp/parsefile > /tmp/parsefile.tmp
mv /tmp/parsefile.tmp /tmp/parsefile
done
bteq<<EOF
.LOGON TEST/karthik,******;
.EXPORT FILE=test1.txt;
.set heading ''
.set titledashes off; 
.set width 1300;
.run file /tmp/parsefile;
.EXPORT RESET;
.QUIT;
.exit;
EOF

sorry for bugging you again

this is not working sir....

even i could not understand your points too as im very new to unix ..

please correct me ..

---------- Post updated at 09:05 AM ---------- Previous update was at 09:01 AM ----------

let me tell what i understood...

1. need to copy the content of SQL.txt into another file ...
2. there i need to replace the parameter content with original value
3. need to use it that for futher SQL processing

---------- Post updated at 12:11 PM ---------- Previous update was at 09:05 AM ----------

thanks sir ....its working fine ....i tried something with ur code(combination urs + my understanding) ..its working fine
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