I want to create a procedure which when I call creates a backup by creating an .sql file and saves it in my computer.
The procedure's name is trial_gen(). When I execute call trial_gen(), it should create a plain .sql file of the schema.
All solutions I found were only using the SQL shell
SQL code is a script, so I think it makes sense to run one from SQL shell. It would be a stored script (text) in a file anyway.
Related
I'm familiarizing myself with the standalone version of Datagrip and having a bit of trouble understanding the different approaches to composing SQL via console, external files, scratch files, etc.
I'm managing, referencing the documentation, and am happy to figure things out as such.
However, I'm trying to ingest CSV data into tables via batch files using the Postgres \copy command. Datagrip will execute this command without error but no data is being populated.
This is my syntax, composed and ran in the console view:
\copy tablename from 'C:\Users\username\data_file.txt' WITH DELIMITER E'\t' csv;
Note that the data is tab-separated and stored in a .txt file.
I'm able to use the import functions of Datagrip (via context menu) just fine but I'd like to understand how to issue commands to do similarly.
\copy is a command of the command-line PostgreSQL client psql.
I doubt that Datagrip invokes psql, so it won't be able to use \copy or any other “backslash command”.
You probably have to use Datagrip's import facilities. Or you start using psql.
Ok, but what about the SQL COPY command https://www.postgresql.org/docs/12/sql-copy.html ?
How can I run something like that with datagrip ?
BEGIN;
CREATE TEMPORARY TABLE temp_json(values text) ON COMMIT DROP;
COPY temp_json FROM 'MY_FILE.JSON';
SELECT values->>'aJsonField' as f
FROM (select values::json AS values FROM temp_json) AS a;
COMMIT;
I try to replace 'MY_FILE.JSON' with full path, parameter (?), I put it in sql directory etc.
The data grip answer is :
[2021-05-05 10:30:45] [58P01] ERROR: could not open file '...' for reading : No such file or directory
EDIT :
I know why. RTFM! -_-
COPY with a file name instructs the PostgreSQL server to directly read from or write to a file. The file must be accessible by the PostgreSQL user (the user ID the server runs as) and the name must be specified from the viewpoint of the server.
Sorry.....
I have multiple tables that are created in the same way (same columns, indexes, etc.)
I would like to have one sql file for creating them all without duplicating the create statements.
Is there a way to use some kind of placeholder in sql file which would be substituted when executing the sql file with a parameter?
For example I would like to have below sql statement:
drop table if exists schema.%PLACEHOLDER%;
create table schema.%PLACEHOLDER%(id text, data text);
And execute such script with:
psql -f mysqlfile.sql -magic_parameter my_desired_table_name
Is this possible when executing PostgreSQL sql files, or maybe other way to achieve the same (except using sed)?
Sincr you are using psql, you can use variables as follows:
drop table if exists schema.:placeholder;
The invocation is:
psql -f mysqlfile.sql -v placeholder=table_name
I have to run some DB2 SQL queries more frequently.It is taking lot of time to do that manually. For that, I am planning to create batch file to execute those DB2 SQL commands.
So,Please let me know whether it is possible to create windows batch file to run set of DB2 sql queries.
You can save a .sql file to your hard drive, and execute it using the DB2 command line using:
db2 -vtf C:\path\to\somefile.sql
-v echoes the command text back to the command line
-t sets the statement terminator to ;. If you want to use something else (creating stored procedures for example), you can use -td__ where __ represents up to two characters you can use as the terminator. Alternatively, you can use --#SET TERMINATOR __ inside your batch file
-f tells the command line to load the commands from the file.
See other command line options here.
I want to copy table from postgis database to the PC hard drive (format can be .txt .xls .csv or whatever).
How it can be done?
Use the SQL COPY command to write to the file system of the database server.
COPY tbl TO '/path/to/file/tbl.sql';
There are lots of options to adapt the output format.
Have a look at the \copy meta-command of psql if you need to copy from a remote server to the local disk.
Using COPY statement of PostgreSQL, we can load data from a text file into data base's table as below:
COPY CME_ERROR_CODES FROM E'C:\\Program Files\\ERROR_CODES\\errcodes.txt' DELIMITER AS '~'
The above statement is run from a machine which has postgresql client where as the server is in another windows machine. Running the above statement is complaining me that ERROR: could not open file "C:\Program Files\ERROR_CODES\errcodes.txt" for reading: No such file or directory.
After some research, i observed that COPY statement is looking for the loader file(errcodes.txt) in the postgresql server's machine at the same path (C:\Program Files\ERROR_CODES). To test this , i have create the same folder structure in the postgresql server's machine and kept the errcodes.txt file in there. Then the COPY statement worked well. It looks very tough constraint for me with COPY statement.
Is there any setting needed to avoid this? or it is the behavior of COPY statement? I didn't find any information on PostgreSQL documents.
here's the standard solution:
COPY foo (i, j, k) FROM stdin;
1<TAB>2<TAB>3
\.
The data must be properly escaped and tab-separated.
Actually, it is in the docs, even in grammar definition you have STDIN... See: http://www.postgresql.org/docs/9.1/static/sql-copy.html
If you're using some programming language with COPY support, you will have pg_putcopy or similar function. So you don't have to worry about escaping and concatenation.
Hints how to do this manually in Python -> Recreating Postgres COPY directly in Python?
The Perl way -> http://search.cpan.org/dist/DBD-Pg/Pg.pm#COPY_support
Hope this helps.
From the documentation
Quote:
COPY with a file name instructs the PostgreSQL server to directly read from or write to a file. The file must be accessible to the server and the name must be specified from the viewpoint of the server. When STDIN or STDOUT is specified, data is transmitted via the connection between the client and the server.
If you want to copy from a local machine file to a server use \copy command.