conditional statement in bash with mysql query - mysql

im trying to write a bash script that will do a mysql query and if the number of results is 1, do something. i cant get it to work though.
#!/bin/sh
file=`mysql -uroot -proot -e "select count(*) from MyTable.files where strFilename='file.txt'"`
if [[ $file == "count(*) 1" ]];
then
echo $file
else
echo $file
echo "no"
fi
i verified the query works. i keep getting this returned
count(*) 1
no
im not sure why but i think it might have something to do with the type of variable $file is. any ideas?


To prevent exposing your database credential in the script you can store them in the local .my.cnf file located in your home directory.
This technic will allow your script to work on any server without modification.
Path: /home/youruser/.my.cnf
Content:
[client]
user="root"
password="root"
host="localhost"
[mysql]
database="MyTable"
So, Renato code could be rewritten by following:
#!/bin/sh
file=`mysql -e "select count(*) as count from files where strFilename='file.txt'" | cut -d \t -f 2`
if [ $file == "1" ];
then
echo $file
else
echo $file
echo "no"
fi


I rewrote your script, it works now:
#!/bin/sh
file=`mysql -uroot -proot -e "select count(*) as count from MyTable.files where strFilename='file.txt'" | cut -d \t -f 2`
if [ $file == "1" ];
then
echo $file
else
echo $file
echo "no"
fi
I'm giving a better name to the count field, using 'cut' to split the mysql output into two fields and putting the content of the second field into $file. Then you can test $file for "1". Hope it helps you..


I'm guessing that isn't actually count(*) 1 but instead count(*)\n1 or something. echo $file will convert all the characters in IFS to a space, but == will distinguish between those whitespace characters. If this is the case, echo "$file" will give you a different result. (Notice the quotes.)

Related

How do not remove leading zero from variable in a Bash MySQL query?

I am trying to query against the database to validate if a registry exists. I created I bash script to make that:
read -p "`echo $'\n '`-------------`echo $'\n '` Insert a CPF: `echo $'\n '`-------------`echo $'\n '`" CPF
USER_IN_OPTOUT=$(mysql -u $BMB_MYSQL_USER -h $BMB_MYSQL_HOST -NB -se "SELECT cpf FROM optout WHERE cpf = $CPF;")
if [[ ${USER_IN_OPTOUT} == *"${CPF:0}"* ]]; then
echo "----------------------------------------"
echo "User already exists."
echo "----------------------------------------"
else
echo "---------------------------------------"
echo "User does not exists."
echo "---------------------------------------"
exit 1
fi
The variable CPF ($CPF) is equal to 00324323721. As this registry exists it returns the cpf, as expected. However, this query is removing leading zeros returning 324323721. I expect that the returns be exactly 00324323721. How can I do that?

Mysql error handling in queries bash script

I need to catch any invalid credentials while connecting to MariaDB, and overwrite the stderr stream explaining the error.
I have tried to use the following since it seemed to be the easiest and shortest code, but the database throws it's own error instead of displaying mine so I do not think the condition is even working.
right after the mysql command
if [ "$?" -eq 0 ]; then
echo "There is something wrong with the arguments provided">&2
exit 2
else
: #some code
fi
TABLES=$(mysql --skip-column-name -u $USER -pPASSWORD $DB -e "SHOW TABLES;" | grep -v '+' | cut -d' ' -f2)
if [ "$?" -eq- 0 ]; then
echo "There is something wrong with the arguments provided">&2
exit 2
else
: #some code
fi
I was expecting to see my stderr message appearing instead it is showing the mariadb error message on the screen.

The exit status of a pipeline is the status of the last command in the pipeline. So in your case, it's the status of cut, not mysql.
You can use the PIPESTATUS array to get the exit status of other commands in the pipeline. However, this is tricky when the pipeline is in a command substitution, because you need PIPESTATUS from the subshell. See Pipe status after command substitution
If you don't want to see the database error message, you need to redirect stderr.
You need to check if the status is not 0. In the shell, 0 means success.
TABLES=$(mysql --skip-column-name -u $USER -pPASSWORD $DB -e "SHOW TABLES;" 2>/dev/null | grep -v '+' | cut -d' ' -f2; echo ": ${PIPESTATUS[0]}")
status=${TABLES##*: }
if [ $status -ne 0 ]
then
echo "There is something wrong with the arguments provided">&2
exit 2
else
# Remove the appended status
TABLES=${TABLES%:*}
TABLES=${TABLES%$'\n'}
fi

Newbie: unix bash, nested if statement, results from a loop results from sql

Newbie here, please pardon any confusing wording that I use.
A common task I have is to take a list of names and do a MySQL query to look the names up in a table and see if they are "live" on our site.
Doing this one at a time, my SQL query works fine. I then wanted to do the query using a loop from a file listing multiple names. This works fine, too.
I added this query loop to my bash profile so that I can quickly do the task by typing this:
$ ValidOnSite fileName
This works fine, and I even added an usage statement for my process to remind myself of the syntax. Below is what I have that works fine:
validOnSite() {
if [[ "$1" == "" ]] || [[ "$1" == "-h" ]] || [[ "$1" == "--help" ]]; then
echo "Usage:"
echo " $ validOnSite [filename]"
echo " Where validOnSite uses specified file as variables in sql query:"
echo " SELECT name, active FROM dbDb WHERE name=lines in file"
else
cat $1 | while read line ; do hgsql -h genome-centdb hgcentral -Ne "select name, active from dbDb where name='$line'" ; done
fi
Using a file "list.txt" which contains:
nameA
nameB
I would then type:
validOnSite list.txt
and both entries in list.txt meet my query criteria and are found in sql. My results will be:
nameA 1
nameB 1
Note the "1" after each result. I assume this is some sort of "yes" status.
Now, I add a third name to my list.txt, one that I know is not a match in sql. Now list.txt contains:
nameA
nameB
foo
When I again run this command for my list with 3 rows:
validOnSite list.txt
My results are the same as when I used the 1st version of file.txt, and I cannot see which lines failed, I still only see which lines were a success:
nameA 1
nameB 1
I have been trying all kinds of things to add a nested if statement, something that says, "If $line is a match, echo "pass", else echo "fail."
I do not want to see a "1" in my results. Using file.txt with 2 matches and 1 non-match, I would like my results to be:
nameA pass
nameB pass
foo fail
Or even better, color code a pass with green and a fail with red.
As I said, newbie here... :)
Any pointers in the right direction would help. Here is my latest sad attempt, but I realize I may be going in a wrong direction entirely:
validOnSite() {
if [[ "$1" == "" ]] || [[ "$1" == "-h" ]] || [[ "$1" == "--help" ]]; then
echo "Usage:"
echo " $ validOnSite [filename]"
echo " Where validOnSite uses specified file as variables in sql query:"
echo " SELECT name, active FROM dbDb WHERE name=lines in file"
else
cat $1 | while read line ; do hgsql -h genome-centdb hgcentral -Ne "select name, active from dbDb where name='$line'" > /dev/null ; done
if ( "status") then
echo $line "failed"
echo $line "failed" >> outfile
else
echo $line "ok"
echo $line "ok" >>outfile
clear
cat outfile
fi
fi
If something looks crazy in my last attempt, it's because it is - I am just googling around and trying as many things as I can while trying to learn. Any help appreciated, I feel stuck after working on this for a long time, but I am excited to move forward and find a solution! I think there is something I'm missing about understanding stdout, and also confusion about nested if's.
Note: I do not need an outfile, but it's ok if one is needed to accomplish the goal. stdout result alone would suffice, and is preferred.
Note: hgssql is just the name of our MySQL server. The MySQL part works fine, I am looking for a better way to deal with my bash output, and I think there is something about stderr that I'm missing. I'm looking for a fairly simple answer as I'm a newbie!

I guess, by hgsql you mean some Mercurial extension that allows to perform MySQL queries. I don't know how hgsql works, but I know that MySQL returns only the matching rows. But in terms of shell scripting, the result is a string that may contain extra information even if the number of matched rows is zero. For example, some MySQL client may return the header or a string like "No rows found", although it is unlikely.
I'll show how it is done with the official mysql client. I'm sure you will manage to adapt hgsql with the help of its documentation to the following example.
if [ -t 1 ]; then
red_color=$(tput setaf 1)
green_color=$(tput setaf 2)
reset_color=$(tput sgr0)
else
red_color=
green_color=
reset_color=
fi
colorize_flag() {
local color
if [ "$1" = 'fail' ]; then
color="$red_color"
else
color="$green_color"
fi
printf '%s' "${color}${1}${reset_color}"
}
sql_fmt='SELECT IF(active, "pass", "fail") AS flag FROM dbDb WHERE name = "%s"'
while IFS= read -r line; do
sql=$(printf "$sql_fmt" "$line")
flag=$(mysql --skip-column-names dbname -e "$sql")
[ -z "$flag" ] && flag='fail'
printf '%-20s%s\n' "$line" "$(colorize_flag "$flag")"
done < file
The first block detects if the script is running in interactive mode by checking if the file descriptor 1 (standard output) is opened on a terminal (see help test). If it is opened in a terminal, the script considers that the script is running interactively, i.e. the standard output is connected to the user's terminal directly, but not via pipe, for example. For interactive mode, it assigns variables to the terminal color codes with the help of tput command.
colorize_flag function accepts a string ($1) and outputs the string with the color codes applied according to its value.
The last block reads file line by line. For each line builds an SQL query string (sql) and invokes mysql command with the column names stripped off the output. The output of the mysql command is assigned to flag by means of command substitution. If "$flag" is empty, it is assigned to 'fail'. The $line and the colorized flag are printed to standard output.
You can test the non-interactive mode by chaining the output via pipe, e.g.:
./script | tee -a
I must warn you that it is generally bad idea to pass the shell variables into SQL queries unless the values are properly escaped. And the popular shells do not provide any tools to escape MySQL strings. So consider running the queries in Perl, PHP, or any programming language that is capable of building and running the queries safely.
Also note that in terms of performance it is better to run a single query and then parse the result set in a loop instead of running multiple queries in a loop, with the exception of prepared statements.

I found a way to get to my solution by piecing together the few basic things that I know. Not elegant, but it works well enough for now. I created a file "[filename]Results" with the output:
nameA 1
nameB 1
I then cut out the "1"s and made a new file. I then did a comparison with "[fileName]results" to list.txt in order to see what lines exist in file.txt but do not exist in results.
Note: I have the following in my .zshrc file.
validOnSite() {
if [[ "$1" == "" ]] || [[ "$1" == "-h" ]] || [[ "$1" == "--help" ]]; then
echo "Usage:"
echo " $ validOnSite [filename]"
echo " Where validOnSite uses specified file as variables in sql query:"
echo " SELECT name, active FROM dbDb WHERE name=lines in file"
else
cat $1 | while read line ; do hgsql -h genome-centdb hgcentral -Ne "select name from dbDb where name='$line' and active='1'" >> $1"Pass"; done
autoload -U colors
colors
echo $fg_bold[magenta]Assemblies active on site${reset_color}
echo
cat $1"Pass"
echo
echo $fg_bold[red]Not active or not found on site${reset_color}
comm -23 $1 $1"Pass" 2> /dev/null
echo
echo
mv $1"Pass" ~cath/myFiles/validOnSiteResults
echo "Results file containing only active assemblies resides in ~cath/myFiles/validOnSiteResults"
fi
}
list.txt:
nameA
nameB
foo
My input:
validOnSite list.txt
My output:
Assemblies active on site (<--this font is magenta)
nameA
nameB
Not active or not found on site (<--this font is red)
foo
Results file containing only active assemblies resides in ~me/myFiles/validOnRRresults

Passing multiple parameters from shell script to mysql query

I have to write a unix shell script which will take the parameters for MySQL and export the result into csv file.
I have written to some extent but am unable to pass the multiple parameters from shell script to sql.
Can anyone help me out in this? Thanks!!

assuming you call the script like this
$ ./script param1 param2 param3
in the script
echo $0 #will echo 'script' (the name of the script)
echo $1 #will echo 'param1'
echo $2 #will echo 'param2'
echo $3 #will echo 'param3'
echo $# #will echo '3' the number of params passed to script
echo $# #will echo 'param1 param2 param3' (all the parameters passed)
host="127.0.0.1"
user="root"
password="pass"
result=`mysql -h $host --user=$user --password=$password --skip-column-names -e "select $param1 from $param2 where $param3 = 3"`
echo $result

mysql -e "set #param1:=4897, #param2:=2; source the_script.sql;"
And the script:
SELECT #param1, #param2;
P.S. BTW, I recommend to pass connection parameters using --defaults-extra-file option.

MySQL error in Bash

i'm trying to load some tables to mysql into a bash script so i have the followin code
DOMY="$MYSQL --user=xxxxx --password=xxxxx --database=$DBNAME"
for filename in $(cat $HPATH/toload.tables)
do
$DOMY < $filename 2>/dev/null
if [ $? -ne 0 ]
then
echo "#003|Error loading $filename"
exit 1
fi
done
if i see $? (echo $?) it give me 0 (zero) but the exit 1 is executed.
What i'm doin wrong?

You can't see what's wrong because you have /dev/null-ed standard error.
Also, you are using an unnecessarily complex and somewhat error-prone code pattern where you examine $? later. It would be better to just write something like:
for i in "$#"; do
if mysql -u root < $i; then
echo ok # do "ok" processing here
else
echo not so ok # error path
fi
done