I have the following query which generates a list of ALTER TABLE statements in the 'Data Output' field in pgAdmin4. I can copy & paste them back into the query pane and execute them there.
select 'ALTER TABLE ' || table_name || ' OWNER TO myuser;' from information_schema.tables where table_schema = 'public';
How can I execute the generated statements without having to copy & paste them?
You can use the function for that.
CREATE OR REPLACE FUNCTION change_permission_table()
RETURNS VOID AS $$
DECLARE
rec text;
BEGIN
FOR rec IN SELECT 'ALTER TABLE ' || table_name || ' OWNER TO maz;' FROM information_schema.tables WHERE table_schema = 'public'
LOOP
EXECUTE rec;
END LOOP;
END;
$$ LANGUAGE plpgsql;
-- Run the function to change the permission
SELECT change_permission_table()
Related
I'm new to plpgsql. I'm sure there is some really simple way to do this, but for some reason I'm having a lot of trouble trying to figure out how to do this.
I'm simply trying to loop through the list of existing tables and execute
CREATE TABLE z_existing_table_name AS SELECT * FROM existing_table_name WITH DATA
So far, I have this:
CREATE OR REPLACE FUNCTION create_backup_row()
RETURNS RECORD
AS $$
DECLARE
row RECORD;
BEGIN
FOR row IN SELECT * FROM information_schema.tables WHERE table_catalog = 'my_db' and table_schema = 'public'
LOOP
EXECUTE 'CREATE TABLE z_' || t.table_name || ' as ' || t.table_name
END LOOP;
END;
$$ LANGUAGE plpgsql;
It would be an added bonus if I can make this function re-runnable. Something like drop table if exist then create table ...
#Steven, use below procedure,
-- Function: create_backup_row()
-- DROP FUNCTION create_backup_row();
CREATE OR REPLACE FUNCTION create_backup_row()
RETURNS integer AS
$BODY$
DECLARE
v_table text;
BEGIN
FOR v_table IN
SELECT table_name
FROM information_schema.tables
WHERE table_catalog = 'my_db'
AND table_schema = 'public'
AND table_name not ilike '%z_%' -- to skip the table with z_ when we rerun it.
LOOP
EXECUTE ' DROP TABLE IF EXISTS z_' || v_table ;
EXECUTE 'CREATE TABLE z_' || v_table || ' as SELECT * FROM ' || v_table ;
END LOOP;
return 1;
END;
$BODY$
LANGUAGE plpgsql VOLATILE
COST 100;
ALTER FUNCTION create_backup_row()
OWNER TO postgres;
for some reason I just can not figure this out. I have a seperate schema in PostgreSQL for notification related tables for each user connected to the server. My plan is to have each user create a TEMP table to receive extra notification info from since Xojo doesn't support PostgreSQL payloads.
I feel like I'm starting to get close so I'll just post my code that is in my trigger function.
DECLARE
my_table RECORD;
BEGIN
FOR my_table IN
SELECT table_name
FROM information_schema.tables
WHERE table_schema = 'information_schema'
LOOP
INSERT INTO my_table.table_name (effected_row_id)
VALUES (NEW.effected_row_id);
END LOOP;
END;
Tell me if I'm wrong, but I believe my main problem is figuring out how to use the table name returned from the SELECT statement in the INSERT statement.
EDIT:
This is my current trigger function
-- Function: notification.my_insert_trigger_function()
-- DROP FUNCTION notification.my_insert_trigger_function();
CREATE OR REPLACE FUNCTION notification.my_insert_trigger_function()
RETURNS trigger AS
$BODY$DECLARE
my_table RECORD;
BEGIN
FOR my_table IN
SELECT table_name
FROM information_schema.tables
WHERE table_schema = 'notification' AND table_name <> 'notification_global' AND table_name <> 'switcher'
LOOP
EXECUTE(FORMAT($f$
INSERT INTO %s (effected_row_username)
VALUES (%s);
$f$, 'notification.' || my_table.table_name, NEW.effected_row_username));
END LOOP;
RETURN new;
END;$BODY$
LANGUAGE plpgsql VOLATILE
COST 100;
ALTER FUNCTION notification.my_insert_trigger_function()
OWNER TO serveradmin;
You need to use dynamic commands in your trigger function.
The funcion format() is often very helpful.
DECLARE
my_table RECORD;
BEGIN
FOR my_table IN
SELECT table_name
FROM information_schema.tables
WHERE table_schema = 'information_schema'
LOOP
EXECUTE(FORMAT($f$
INSERT INTO %s (effected_row_id)
VALUES (%s);
$f$, my_table.tablename, NEW.effected_row_id));
END LOOP;
END;
For some fancy database maintenance for my developer database I'd like to be able to use queries to generate commands to alter the database. The thing is: I'm a complete greenhorn to PostgreSQL. I've made my attempt but have failed colorfully.
So in the end, I would like to have a table with a single column and each row would be a command (or group of commands, depending on the case) that I would think would look something like this...
DO $$
DECLARE
command_entry RECORD;
BEGIN
FOR command_entry IN SELECT * FROM list_of_commands
LOOP
EXECUTE command_entry;
END LOOP;
END;
$$;
Where the table list_of_commands could be populated with something like the following (which in this example would remove all tables from the public schema)...
CREATE TEMP TABLE list_of_commands AS
SELECT 'drop table if exists "' || tablename || '" cascade;'
FROM pg_tables
WHERE schemaname = 'public';
However, with this I get the following error...
ERROR: syntax error at or near ""drop table if exists ""dummy_table"" cascade;""
LINE 1: ("drop table if exists ""dummy_table"" cascade;")
I assume this is a matter of escaping characters, but I'm not entirely sure how to fit that into either A) the population of the table or B) the execution of each row. Does anyone know what I could do to achieve the desired result?
The command_entry variable is of type record while the EXECUTE command expects a string. What is apparently happening is that PostgreSQL turns the record into a double-quoted string, but that messes up your command. Also, your temp table does not use a column name, making things a bit awkward to work with (the column name becomes ?column?), so change both as follows:
CREATE TEMP TABLE list_of_commands AS
SELECT 'drop table if exists public.' || quote_ident(tablename) || ' cascade' AS cmd
FROM pg_tables
WHERE schemaname = 'public';
DO $$
DECLARE
command_entry varchar;
BEGIN
FOR command_entry IN SELECT cmd FROM list_of_commands
LOOP
EXECUTE command_entry;
END LOOP;
END;
$$;
But seeing that you do all of this at session level (temp table, anonymous code block), why not write a stored procedure that performs all of this housekeeping when you are ready to do spring cleaning?
CREATE FUNCTION cleanup() RETURNS void AS $$
BEGIN
FOR tbl IN SELECT tablename FROM pg_tables WHERE schemaname = 'public'
LOOP
EXECUTE 'DROP TABLE IF EXISTS ' || quote_ident(tbl) || ' CASCADE';
END LOOP;
-- More housekeeping jobs
END;
$$ LANGUAGE plpgsql;
This saves a lot of typing: SELECT cleanup();. Any other housekeeping jobs you have you simply add to the stored procedure.
I had trouble with Patrick's answers, so here is an updated version for postgreSQL 10.
CREATE FUNCTION droptables(sn varchar) RETURNS void AS $$
DECLARE
tbl varchar;
BEGIN
FOR tbl IN SELECT tablename FROM pg_tables WHERE schemaname = sn
LOOP
EXECUTE 'DROP TABLE IF EXISTS ' || quote_ident(tbl) || ' CASCADE';
END LOOP;
END;
$$ LANGUAGE plpgsql;
And then "SELECT droptables('public');".
I have been using the following code for dropping all tables that share the same prefix (in this case delete all tables that their name starts with 'supenh_'):
DO
$do$
DECLARE
_tbl text;
BEGIN
FOR _tbl IN
SELECT quote_ident(table_schema) || '.'
|| quote_ident(table_name) -- escape identifier and schema-qualify!
FROM information_schema.tables
WHERE table_name LIKE 'supenh_' || '%' -- your table name prefix
AND table_schema NOT LIKE 'pg_%' -- exclude system schemas
LOOP
-- RAISE NOTICE '%',
EXECUTE
'DROP TABLE ' || _tbl;
END LOOP;
END
$do$;
Is there a way to amend this code / or to use a different script in order to delete from one specific table all the columns that start with the same prefix (for example, 'patient1_') ?
You could write it as PL/pgSQL function:
CREATE OR REPLACE FUNCTION drop_columns_with_prefix(tbl_name TEXT, column_prefix TEXT) RETURNS VOID AS
$BODY$
DECLARE
_column TEXT;
BEGIN
FOR _column IN
SELECT quote_ident(column_name)
FROM information_schema.columns
WHERE table_name = tbl_name
AND column_name LIKE column_prefix || '%'
AND table_schema NOT LIKE 'pg_%'
LOOP
-- RAISE NOTICE '%',
EXECUTE
'ALTER TABLE ' || tbl_name || ' DROP COLUMN ' || _column;
END LOOP;
END
$BODY$
LANGUAGE plpgsql VOLATILE;
Call it using:
SELECT drop_columns_with_prefix('tbl_name', 'prefix_');
Or if you don't want to use it as a function:
DO
$do$
DECLARE
_column TEXT;
BEGIN
FOR _column IN
SELECT quote_ident(column_name)
FROM information_schema.columns
WHERE table_name = 'tbl_name'
AND column_name LIKE 'prefix_%'
AND table_schema NOT LIKE 'pg_%'
LOOP
-- RAISE NOTICE '%',
EXECUTE
'ALTER TABLE tbl_name DROP COLUMN ' || _column;
END LOOP;
END
$do$
I have a PostgreSQL 9.1 database with 100 or so tables that were loaded into the 'public' schema. I would like to move those tables (but not all of the functions in 'public') to a 'data' schema.
I know that I can use the following to move 1 table at a time.
ALTER TABLE [tablename] SET SCHEMA [new_schema]
Is it possible to move all of the tables to the new schema in one operation? If so, what would be the most efficient way to accomplish this task?
DO will do the trick:
DO
$$
DECLARE
row record;
BEGIN
FOR row IN SELECT tablename FROM pg_tables WHERE schemaname = 'public' -- and other conditions, if needed
LOOP
EXECUTE format('ALTER TABLE public.%I SET SCHEMA [new_schema];', row.tablename);
END LOOP;
END;
$$;
-- ####### USING DBEAVER WHICH SUPPORT VARIABLES ########
-- ### ANSWER_1 -- USING DO ###--------
-- Step1: Set variables one by one
#set _SCHEMA = 'public'
#set _COLUMN = 'dml_status'
#set _DATA_TYPE = 'integer'
#set _DEFAULT = '1'
-- Step2: Call the below procedure
DO
$$
DECLARE
row record;
query varchar;
BEGIN
FOR ROW IN SELECT table_name FROM information_schema.tables WHERE table_schema = ${_SCHEMA}
LOOP
query :='ALTER TABLE public.' || quote_ident(row.table_name) ||' ADD COLUMN IF NOT EXISTS '||${_COLUMN} || ' ' || ${_DATA_TYPE} ||' not null default ' || ${_DEFAULT} || ';' ;
execute query;
END LOOP;
END;
$$;
-- ### ANSWER_2 -- STORE PROCEDURE FN ###--------
DROP FUNCTION addColumnToMultipleTables cascade;
create or replace function addColumnToMultipleTables()
returns void
LANGUAGE 'plpgsql'
as $$
DECLARE
row record;
query varchar;
BEGIN
FOR ROW IN SELECT table_name FROM information_schema.tables WHERE table_schema = ${_SCHEMA}
LOOP
query :='ALTER TABLE public.' || quote_ident(row.table_name) ||' ADD COLUMN IF NOT EXISTS '||${_COLUMN} || ' ' || ${_DATA_TYPE} ||' not null default ' || ${_DEFAULT} || ';' ;
raise info 'query : % ', query;
execute query;
END LOOP;
END;
$$;
select addColumnToMultipleTables();