I have a nice bash script that uses az cli to generate an Azure SQL Server (az sql server create) and SQL database (az sql db create).
I'd like to populate the database with tables and columns I have defined in a series of .sql files stored in Github.
Example file:
Filename: TST_HDR.sql
File contents:
-- Create a new table called 'TEST_HDR' in schema 'dbo'
-- Drop the table if it already exists
IF OBJECT_ID('dbo.TEST_HDR', 'U') IS NOT NULL
DROP TABLE dbo.TEST_HDR
GO
-- Create the table in the specified schema
CREATE TABLE dbo.TEST_HDR
(
tstID INT IDENTITY(1,1) NOT NULL PRIMARY KEY,
tstGUID [NVARCHAR](50),
tstComments [NVARCHAR](2000),
tstHdrCreated DATETIME2,
tstHdrCreatedBy [NVARCHAR](255),
tstHdrLastUpdated DATETIME2,
tstHdrLastUpdatedBy [NVARCHAR](255),
tstHdrDeleted [NVARCHAR](3),
tstHdrDeletedBy [NVARCHAR](255),
tstHdrVersionNum INT
);
GO
Which bash (or other scripting) commands do I use to get these files from Github and execute them against the SQL database?
Assuming you have sqlcmd installed:
tmp=$(mktemp) && \
curl -sL https://raw.githubusercontent.com/path/to/your/TST_HDR.sql > ${tmp} && \
sqlcmd -S <servername>.database.windows.net -d <database> -U <user> -P <password> -i ${tmp}
mkdir (create directory)
cd (to the directory created, for the Github repository)
git clone (The address to the repository where your sql file is located)
Make sure the ports are accessible on the pc you are connecting from and on the server you are connecting to.
sqlcmd -d (database) -i (filepath to the sql file, in the git repository) -P (password) -S (servername).database.windows.net -U (user)
Related
I am running a bash script to extract data from a table via presto...
./presto --server myprestoserver:8889 --catalog mycatalog --schema myschema --execute "select * from TABLEResultsAuditLog;" > /mydirectory/audit.dat
This command will successfully and extract the table results and send them to the audit.dat file. What I am looking for is to replace the
--execute "select * from TABLEResultsAuditLog;"
section and have a file located in /mydirectory/audit.sql which would then contain the sql statement which I need executed. I have tried using
./presto --server myprestoserver:8889 --catalog mycatalog --schema myschema < /mydirectory/audit.sql > /mydirectory/audit.dat
where the audit.sql contains the select statement only, but this only populates the audit.dat file with the query statement and not the results. I'm not familiar with bash scripting, so its probably an easy fix for someone!!
Presto CLI has --file option for this purpose:
presto-cli --server ... --file input.sql > output-file
I am trying to create a PostgreSQL database accounts_db in CI (GitLab CI, if it's relevant), but only if that database does not exist yet. Since native Postgres doesn't support that, I currently solve it by running a SELECT on pg_database using psql, and only when that does not return results, I use psql again to run a CREATE DATABASE:
psql -tc "SELECT 1 FROM pg_database WHERE datname = 'accounts_db';" | grep -q 1 || psql -c "CREATE DATABASE accounts_db;"
This works most of the time: accounts_db already exists, so grep exits successfully and the CREATE DATABASE is not executed.
Most of the time is not all the time, though. For some reason, it sometimes ends up in the second part of the ||, only to error out because the database already exists:
$ psql -tc "SELECT 1 FROM pg_database WHERE datname = 'accounts_db';" | grep -q 1 || psql -c "CREATE DATABASE accounts_db;"
ERROR: database "accounts_db" already exists
How is this possible?
BTW: You don't need grep; you can use psql's exit code,just attempt connecting to the new database:
(there are more reasons for psql to exit with non zero exit value; but in that case the second psql will also fail)
#!/bin/sh
THE_NAME="omg_wtf"
psql -U postgres ${THE_NAME} -tc "select 'yes';" || psql -U postgres postgres -tc "CREATE DATABASE ${THE_NAME} ;"
#Eof
But even simpler: just attempt to create the database, and bail out of the script if that fails:
#!/bin/sh
THE_NAME="omg_wtf"
psql -U postgres postgres -tc "CREATE DATABASE ${THE_NAME} ;"|| exit 1
# you wont get here if the above exited
echo "Created ${THE_NAME}"
#Eof
Any chance you've obfuscated the real db name, and the real one sometimes contains mixed case?
Because
SELECT 1 FROM pg_database WHERE datname = 'MyDB'
will match a database named MyDB but not one named mydb. However, if you create the database, you'll get a case-folded name; e.g.
CREATE DATABASE MyDB;
creates a db named mydb. So in this case, your test for existence would report that there's no db named MyDB then you'd go to create it, try to create mydb and fail if it already existed.
The fix is to use identifier quoting:
CREATE DATABASE "MyDB";
to preserve case there. Or alternately, case-fold your query of pg_database to lower case:
SELECT 1 FROM pg_database WHERE datname = lower('MyDB')
... assuming you know you'll only ever attempt to then create it in lower-case.
(It gets even more exciting if the user decides to supply identifier-quoted input to your script...)
I'm looking for a way to restore my DB from a prior backup. However, the backup should not simply overwrite all existing records but instead add only the difference between current DB and the backup file. If no "non existent" records are stored in the backup, nothing should happen. The backups were made with mysqldump. Any clues?
Thanks in advance
Here is a less manual answer:
mysqldump -t --insert-ignore --skip-opt -u USER -pPASSWORD -h 127.0.0.1 database > database.sql
That export command with the -t --insert-ignore --skip-opt options will give you a sql dump file with no DROP TABLE or CREATE TABLE commands and every INSERT is now an INSERT IGNORE.
BONUS:
This will dump a single table in the same way:
mysqldump -t --insert-ignore --skip-opt -u USER -pPASSWORD -h 127.0.0.1 database table_name > table_name.sql
I needed this today and could not help but to share it!
Remove the DROP TABLE and CREATE TABLE statements from the dump file. Change the INSERT statements to INSERT IGNORE. Then load the backup file and it should not update any duplicate rows.
I am trying to automate a set of procedures that create TEMPLATE databases.
I have a set of files (file1, file2, ... fileN), each of which contains a set of pgsql commands required for creating a TEMPLATE database.
The contents of the file (createdbtemplate1.sql) looks roughly like this:
CREATE DATABASE mytemplate1 WITH ENCODING 'UTF8';
\c mytemplate1
CREATE TABLE first_table (
--- fields here ..
);
-- Add C language extension + functions
\i db_funcs.sql
I want to be able to write a shell script that will execute the commands in the file, so that I can write a script like this:
# run commands to create TEMPLATE db mytemplate1
# ./groksqlcommands.sh createdbtemplate1.sql
for dbname in foo foofoo foobar barbar
do
# Need to simply create a database based on an existing template in this script
psql CREATE DATABASE $dbname TEMPLATE mytemplate1
done
Any suggestions on how to do this? (As you may have guessed, I'm a shell scripting newbie.)
Edit
To clarify the question further, I want to know:
How to write groksqlcommands.sh (a bash script that will run a set of pgsql cmds from file)
How to create a database based on an existing template at the command line
First off, do not mix psql meta-commands and SQL commands. These are separate sets of commands. There are tricks to combine those (using the psql meta-commands \o and \\ and piping strings to psql in the shell), but that gets confusing quickly.
Make your files contain only SQL commands.
Do not include the CREATE DATABASE statement in the SQL files. Create the db separately, you have multiple files you want to execute in the same template db.
Assuming you are operating as OS user postgres and use the DB role postgres as (default) Postgres superuser, all databases are in the same DB cluster on the default port 5432 and the role postgres has password-less access due to an IDENT setting in pg_hba.conf - a default setup.
psql postgres -c "CREATE DATABASE mytemplate1 WITH ENCODING 'UTF8'
TEMPLATE template0"
I based the new template database on the default system template database template0. Basics in the manual here.
Your questions
How to (...) run a set of pgsql cmds from file
Try:
psql mytemplate1 -f file
Example script file for batch of files in a directory:
#! /bin/sh
for file in /path/to/files/*; do
psql mytemplate1 -f "$file"
done
The command option -f makes psql execute SQL commands in a file.
How to create a database based on an existing template at the command line
psql -c 'CREATE DATABASE my_db TEMPLATE mytemplate1'
The command option -c makes psql execute a single SQL command string. Can be multiple commands, terminated by ; - will be executed in one transaction and only the result of the last command returned.
Read about psql command options in the manual.
If you don't provide a database to connect to, psql will connect to the default maintenance database named "postgres". In the second answer it is irrelevant which database we connect to.
you can echo your commands to the psql input:
for dbname in foo foofoo foobar barbar
do
echo """
CREATE DATABASE $dbname TEMPLATE mytemplate1
""" | psql
done
If you're willing to go the extra mile, you'll probably have more success with sqlalchemy. It'll allow you to build scripts with python instead of bash, which is easier and has better control.
As requested in the comments: https://github.com/srathbun/sqlCmd
Store your sql scripts under a root dir
Use dev,tst,prd parametrized dbs
Use find to run all your pgsql scripts as shown here
Exit on errors
Or just git clone the whole tool from here
For that use case where you have to do it....
Here is a script I've used for importing JSON into PostgreSQL (WSL Ubuntu), which basically requires that you mix psql meta commands and SQL in the same command line. Note use of the somewhat obscure script command, which allocates a pseudo-tty:
$ more update.sh
#!/bin/bash
wget <filename>.json
echo '\set content `cat $(ls -t <redacted>.json.* | head -1)` \\ delete from <rable>; insert into <table> values(:'"'content'); refresh materialized view <view>; " | PGPASSWORD=<passwd> psql -h <host> -U <user> -d <database>
$
How to create a backup of an POSTGRES DB using bash?
pg_dump -U some_user_name -f dump.file -Fc database_name
That's all.
If you need to authenticate with password - use pgpass file.
Use pg_dump.
Ideally you should add an scheduled job to crontab to be executed daily. The following will create a gzipped sql file with timestamp. SQL dumps otherwise could be very big.
pg_dump database_name | gzip -c > ~/backup/postgres/database_name-`/bin/date +%Y%m%d-%H%M`.sql.gz