Reuse same sql clause in script - sql

The case is that I have an SQL clause inside a unix script like:
sqlplus -s user/pass << END_SQL1 >> outfile.txt
set echo off feedback off heading off tab off;
select .....
from ....
where ...
and ...
and ... ;
END_SQL
If the outfile.txt is not empty, which means that I get a result from the above SQL, then I am running an update SQL that should change something at some DB elements.
Then I need to reuse the same SQL above to check if the DB elements that I wanted have changed indeed. So, is that possible to reuse this same SQL, but WITHOUT including this same SQL code again later at the script, instead to run it again and, moreover, even put the result at another output file, e.g. outfile2.txt ?

You can use RETURNING ... INTO ... clause inside the script
UPDATE myTable
SET col1 = <something1>
WHERE col2 = <something2>
RETURNING col3, col1 INTO v_col3, v_col1;
to return the results into the variables v_col3 and v_col1.

You could put your hairy SELECT query in a file, say select.sql. Then whenever you need to run the SQL, you could just do :
sqlplus -s user/pass #select.sql >> outfile.txt
You can adapt the output file as you wish :
sqlplus -s user/pass #select.sql >> outfile2.txt
NB : you said
If the outfile.txt is not empty, which means that I get a result from the above SQL
You probably want to use > when writing to outfile.txt : >> appends to the file, while > replaces it.

Related

Store my "Sybase" query result /output into a script variable

I need a variable to keep the results retrieved from a query (Sybase) that´s in a script.
I have built the following script, it works fine I get the desired result when I run it
Script: EXECUTE_DAILY:
isql -U database_dba -P password <<EOF!
select the_name from table_name where m_num="NUMB912" and date="17/01/2019"
go
quit
EOF!
echo "All Done"
Output:
"EXECUTE_DAILY" 97 lines, 293 characters
user#zp01$ ./EXECUTE_DAILY
the_name
-----------------------------------
NAME912
(1 row affected)
But now I would like to keep the output(the_name: NAME912) in a variable.
So far this is basically what I'm trying with no success.
variable=$(isql -U database_dba -P password -se "select the_name from table_name where m_num="NUMB912" and date="17/01/2019" ")
But, is not working. I can't save NAME912 in a variable.
You need to parse the output for the desired string/piece-of-data that you wish to store in your variable. I tend to make my life a bit easier by making sure I can easily/quickly search/parse out what I want.
Keeping a few issues in mind ...
I tend to use isql -s"|" -w10000 to ensure (most of the time) that a) the result set has all columns delimited with the pipe ('|') and b) a single row of data does not span multiple rows; the pipe delimiter makes it easier to parse out columns that may contain white space; obviously (?) use a different delimiter if a pipe may be part of your actual data
to make parsing of the isql output a bit easier I tend to add a unique, grep-able (literal) string to the rows that I'm looking to search/parse
some databases (eg, SQLAnywhere, Oracle) tend to mimic a literal value as the column header if said literal string has not been assigned an explicit alias/header; this means that if you do a simple search on your literal string then you'll get a match for the result set header as well as the actual data row
I tend to capture all isql output to a temporary file; this allows for easier follow-on processing, eg, error checking, data parsing, dumping contents to a logfile, etc
So, with the above in mind my code typically looks something like:
$ outfile=/tmp/.$$.isql.outfile
$ isql -s"|" -w10000 -U database_dba -P password <<-EOF > ${outfile} 2>&1
-- 'GREP'||'ME' ensures that 'GREPME' only shows up in the data row
select 'GREP'||'ME',the_name
from table_name
where m_num = "NUMB912"
and date = "17/01/2019"
go
EOF
$ cat ${outfile}
... snip ...
|'GREP'||'ME'|the_name | # notice the default column header = 'GREP'||'ME' which won't match my search for 'GREPME'
|------------|----------|
|GREPME |NAME912 | # this is the line I want to search/parse
... snip ...
$ read -r namevar < <(egrep GREPME ${outfile} | awk -F"|" '{print $3}')
$ echo ${namevar}
NAME912

Generate a Properties File using Shell Script and Results from a SQL Query

I am trying to create a properties file like this...
firstname=Jon
lastname=Snow
occupation=Nights_Watch
family=Stark
...from a query like this...
SELECT
a.fname as firstname,
a.lname as lastname,
b.occ as occupation...
FROM
names a,
occupation b,
family c...
WHERE...
How can I do this? As I am aware of only using spool to a CSV file which won't work here?
These property files will be picked up by shell scripts to run automated tasks. I am using Oracle DB
Perhaps something like this?
psql -c 'select id, name from test where id = 1' -x -t -A -F = dbname -U dbuser
Output would be like:
id=1
name=test1
(For the full list of options: man psql.)
Since you mentionned spool I will assume you are running on Oracle. This should produce a result in the desired format, that you can spool straight away.
SELECT
'firstname=' || firstname || CHR(10) ||
'lastname=' || lastname || CHR(10) -- and so on for all fields
FROM your_tables;
The same approach should be possible with all database engines, if you know the correct incantation for a litteral new line and the syntax for string concatenation.
It is possible to to this from your command line SQL client but as STTLCU notes it might be better to get the query to output in something "standard" (like CSV) and then transform the results with a shell script. Otherwise, because a lot of the features you would use are not part of any SQL standard, they would depend on the database server and client application. Think of this step as sort of the obverse of ETL where you clean up the data you "unload" so that it is useful for some other application.
For sure there's ways to build this into your query application: e.g. if you use something like perl DBI::Shell as your client (which allows you to connect to many different servers using the DBI module) you can jazz up your output in various ways. But here you'd probably be best off if could send the query output to a text file and run it through awk.
Having said that ... here's how the Postgresql client could do what you want. Notice how the commands to set up the formatting are not SQL but specific to the client.
~/% psql -h 192.168.2.69 -d cropdusting -u stubblejumper
psql (9.2.4, server 8.4.14)
WARNING: psql version 9.2, server version 8.4.
Some psql features might not work.
You are now connected to database "cropdusting" as user "stubblejumper".
cropdusting=# \pset border 0 \pset format unaligned \pset t \pset fieldsep =
Border style is 0.
Output format is unaligned.
Showing only tuples.
Field separator is "=".
cropdusting=# select year,wmean_yld from bckwht where year=1997 AND freq > 13 ;
1997=19.9761904762
1997=14.5533333333
1997=17.9942857143
cropdusting=#
With the psql client the \pset command sets options affecting the output of query results tables. You can probably figure out which option is doing what. If you want to do this using your SQL client tell us which one it is or read through the manual page for tips on how to format the output of your queries.
My answer is very similar to the two already posted for this question, but I try to explain the options, and try to provide a precise answer.
When using Postgres, you can use psql command-line utility to get the intended output
psql -F = -A -x -X <other options> -c 'select a.fname as firstname, a.lname as lastname from names as a ... ;'
The options are:
-F : Use '=' sign as the field separator, instead of the default pipe '|'
-A : Do not align the output; so there is no space between the column header, separator and the column value.
-x : Use expanded output, so column headers are on left (instead of top) and row values are on right.
-X : Do not read $HOME/.psqlrc, as it may contain commands/options that can affect your output.
-c : The SQL command to execute
<other options> : Any other options, such as connection details, database name, etc.
You have to choose if you want to maintain such a file from shell or from PL/SQL. Both solutions are possible and both are correct.
Because Oracle has to read and write from the file I would do it from database side.
You can write data to file using UTL_FILE package.
DECLARE
fileHandler UTL_FILE.FILE_TYPE;
BEGIN
fileHandler := UTL_FILE.FOPEN('test_dir', 'test_file.txt', 'W');
UTL_FILE.PUTF(fileHandler, 'firstname=Jon\n');
UTL_FILE.PUTF(fileHandler, 'lastname=Snow\n');
UTL_FILE.PUTF(fileHandler, 'occupation=Nights_Watch\n');
UTL_FILE.PUTF(fileHandler, 'family=Stark\n');
UTL_FILE.FCLOSE(fileHandler);
EXCEPTION
WHEN utl_file.invalid_path THEN
raise_application_error(-20000, 'ERROR: Invalid PATH FOR file.');
END;
Example's source: http://psoug.org/snippet/Oracle-PL-SQL-UTL_FILE-file-write-to-file-example_538.htm
At the same time you read from the file using Oracle external table.
CREATE TABLE parameters_table
(
parameters_coupled VARCHAR2(4000)
)
ORGANIZATION EXTERNAL
(
TYPE ORACLE_LOADER
DEFAULT DIRECTORY test_dir
ACCESS PARAMETERS
(
RECORDS DELIMITED BY NEWLINE
FIELDS
(
parameters_coupled VARCHAR2(4000)
)
)
LOCATION ('test_file.txt')
);
At this point you can write data to your table which has one column with coupled parameter and value, i.e.: 'firstname=Jon'
You can read it by Oracle
You can read it by any shell script because it is a plain text.
Then it is just a matter of a query, i.e.:
SELECT MAX(CASE WHEN INSTR(parameters_coupled, 'firstname=') = 1 THEN REPLACE(parameters_coupled, 'firstname=') ELSE NULL END) AS firstname
, MAX(CASE WHEN INSTR(parameters_coupled, 'lastname=') = 1 THEN REPLACE(parameters_coupled, 'lastname=') ELSE NULL END) AS lastname
, MAX(CASE WHEN INSTR(parameters_coupled, 'occupation=') = 1 THEN REPLACE(parameters_coupled, 'occupation=') ELSE NULL END) AS occupation
FROM parameters_table;

Looping SQL query in Bash script

i am new to bash scripting and i was wondering if anyone could help me with the following.
I am trying to retrieve the competition name from a Oracle database using competition_id using the following statement:
select name, competition_type from competitions where competition_id=' ';
However i want to use a seperate text file whcih has a list competition_ids i want to identify, i want my script to find the name and type of all my ids and output the results in a txt file. this is what i have so far:
#!/bin/bash
echo Start Executing SQL commands
cat comps_ids.txt | while read ID
var=$ID
do
sqlplus "details"
<< EOF
select name, competition_type
from competitions
where competition_id=$var;
exit;
EOF
I tried to add a done at the end but i get "unexpected line ending" error message. Can anyone solve this?
Many thanks in advance :)
I'm not sure what your command line should look like, but it's more like
sqlplus "details" <<EOF
select name, competition_type from competitions where competition_id=$val;
exit;
EOF
If your list of IDs isn't too big, it may be better idea to make a ,-separated list and single query.
#!/bin/bash
function get_comp () {
sqlplus -S user/pass#database << EOF
set pagesize 0
set feedback off
set head off
select name, competition_type
from competitions
where competition_id=$1;
EOF
}
for id in $* ; do
get_comp $id
done
Put it in a file (get_comps.sh), and then call it like this
$ ./get_comps.sh < comp_ids.txt > text_file_out.txt
-S makes sqlplus quieter
The other setting make it return just your data, not row headers or anything else.
Of course the database credentials will be stored in your history, and available to other users using 'ps' or 'top'.
This is also horribly inefficient because it connects to the database for each row in your original file. If you have a lot of rows, you might try using python or ruby as their database stuff is pretty easy to use.

Execute SQL from file in bash

I'm trying to load a sql from a file in bash and execute the loaded sql. The sql file needs to be versatile, meaning it cannot be altered in order to make things easy while being run in bash (escaping special characters like * )
So I have run into some problems:
If I read my sample.sql
SELECT * FROM SAMPLETABLE
to a variable with
ab=`cat sample.sql`
and execute it
db2 `echo $ab`
I receive an sql error because by doing a cat the * has been replaced by all the files in the directory of sample.sql.
Easy solution would be to replace "" with "\" . But I cannot do this, because the file needs to stay executable in programs like DB Visualizer etc.
Could someone give me hint in the right direction?
The DB2 command line processor has options that accept a filename as input, so you shouldn't need to load statements from a text file into a shell variable.
This command will execute all SQL statements in the file, with newline treated as the statement terminator:
db2 -f sample.sql
This command will execute all SQL statements in the file, with semicolon treated as the statement terminator:
db2 -t -f sample.sql
Other useful CLP flags are:
-x : Suppress the column headings
-v : Echo the statement text immediately before execution
-z : Tee a copy of all CLP output to the filename immediately following this flag
Redirect stdin from the file.
db2 < sample.sql
In case, you have a variable used in your script and wanted to get it replaced by the shell before executed in DB2 then use this approach:
Contents of File.sql:
cat <<xEOF
insert values(1,2) into ${MY_SCHEMA}.${MY_TABLE};
select * from ${MY_SCHEMA}.${MY_TABLE};
xEOF
In command prompt do:
export MY_SCHEMA='STAR'
export MY_TAVLE='DIMENSION'
Then you are all good to get it executed in DB2:
eval File.sq |db2 +p -t
The shell will replace the global variables and then DB2 will execute it.
Hope it helps.

Unix putting extra spaces/lines while passing values to sql statement

I have a unix script like this:
value1=`sqlplus -s ivr/ivr <<EOF
set heading off;
set feedback off;
set linesize 500;
set serveroutput on;
set wrap off;
SELECT FM.getSequence_n('$b_period', '$t_period', '$opr', '$fran', '$poi_s')
FROM DUAL;
exit;
EOF` ,
The parameters are taken as input from the user. when i run the script in debug mode using 'ksh -x filename.sh' i notice that when the unix script is passing values to the select statement it breaks it like this:
SELECT FM.getSequence_n('
2010/12/01 - 2010/12/31','
2010/12/01 - 2010/12/31','TTSLAP','UWAP','TTSL-LOC')
FROM DUAL
...which gives the wrong output. When i run the same sql statement with the passed values in sqlplus with all the values in a single line i get the correct output.
I need to know why unix is breaking the statement into multiple lines and how can this be removed. This has been giving me nightmares. Firstly i was thinking that values were not being passed correctly that's why output was wrong . But only this linefeed by unix while passing values is the cause of error. Please help.
It seems like your $b_period and $t_period variables contain newline characters. If they are input directly from users you really should do some input validation first before using them.
Try something like
filtered_b_period=`echo $b_period | sed 's/[^0-9\/]*//g'`
filtered_t_period=`echo $t_period | sed 's/[^0-9\/]*//g'`
Probably you should add further check as well, but at least you should be able to filter out unwanted characters this way.
The values of your variables include newlines. Do something like this to check:
echo "$b_period" | hexdump -C