PostgreSQL: How to add a column in every table of a database? - sql

I have a database with 169 tables
I need this column in every table:
wid integer not null primary key
I tried this(Thanks https://stackoverflow.com/users/27535/gbn for the solution):
SELECT
'ALTER TABLE ' + T.name + ' ADD foo int NULL'
FROM
sys.tables AS T
WHERE
T.is_ms_shipped = 0
But it didn't work on PostgreSQL.
It only worked on tsql.
How to add this column in every table at once ?

do $$
declare
selectrow record;
begin
for selectrow in
select
'ALTER TABLE '|| T.mytable || ' ADD COLUMN foo integer NULL' as script
from
(
select tablename as mytable from pg_tables where schemaname ='public' --your schema name here
) t
loop
execute selectrow.script;
end loop;
end;
$$;
You can test whether all your tables altered with the new column using the following select
select
table_name,COLUMN_NAME
from
INFORMATION_SCHEMA.COLUMNS
where
COLUMN_NAME='foo' -- column name here

Try this (change 'public' to whatever schema you're doing this in)
DO $$
DECLARE
row record;
cmd text;
BEGIN
FOR row IN SELECT schemaname, tablename FROM pg_tables WHERE schemaname = 'public' LOOP
cmd := format('ALTER TABLE %I.%I ADD COLUMN foo SERIAL PRIMARY KEY ', row.schemaname, row.tablename);
RAISE NOTICE '%', cmd;
-- EXECUTE cmd;
END LOOP;
END
$$ LANGUAGE plpgsql;
If you run as is, it'll show you the commands. Uncomment the EXECUTE line to actually perform the alterations.
I'd run within a transaction so you can roll back if you're not happy with the results.
Note that the type is SERIAL - the column type will be integer, but also creates a sequence owned by the table and defaults the column value to the next value of that sequence.

We may need to check column is already exist or not.
Tested on PostgreSQL V10
do $$
declare selectrow record;
begin
for selectrow in
select 'ALTER TABLE '|| T.mytable || ' ADD COLUMN x_is_exported boolean DEFAULT FALSE' as script
from (select tablename as mytable from pg_tables where schemaname ='public') t
loop
begin
execute selectrow.script;
EXCEPTION WHEN duplicate_column THEN CONTINUE;
END;
end loop;
end;
$$;

Related

PL/pgSQL select statement inside trigger returns null using where NEW

i'm creating a trigger that triggers on INSERT on a table,
and i wish to log the structure of tables inserted so i wrote this Function
CREATE OR REPLACE FUNCTION update_table_log_received()
RETURNS TRIGGER AS $$
DECLARE
added_column TEXT;
target_table_name TEXT;
old_column text;
BEGIN
-- Check if a new column has been added
IF (TG_OP = 'INSERT') THEN
added_column := NEW."COLUMN_NAME";
target_table_name := NEW."TABLE_NAME";
END IF;
SELECT column_name into old_column
FROM information_schema."columns"
WHERE table_schema = 'items'
and table_name = LOWER(NEW."TABLE_NAME")
and column_name = LOWER(NEW."COLUMN_NAME");
if (coalesce(old_column,'')='' or old_column='' or old_column = added_column) THEN
-- If a new column has been added
IF (Lower(added_column) != 'sync') then
-- Add the new column to the target table
EXECUTE 'ALTER TABLE items.' || LOWER(target_table_name)|| ' ADD COLUMN ' || LOWER(added_column) || ' VARCHAR(50)';
END IF;
end if;
RETURN NEW;
END;
$$ LANGUAGE plpgsql;
executed by this TRIGGER :
CREATE TRIGGER update_table_log_received_trigger
AFTER INSERT
ON items."TABLE_LOG_RECEIVED"
FOR EACH ROW
EXECUTE FUNCTION update_table_log_received();
the returned exception is the following :
! ERROR: the column « x » of the relation « y » already exists
Where: instruction SQL « ALTER TABLE items. ADD COLUMN x VARCHAR(50) »
my problem now is that it isn't supposed to pass the If checks (i pasted the code after many alterations i have two if conditions that do the same thing just because),
i debugged and logged the statements to note that the select query inside my function returns null apparently.
i also tried to use "USING NEW" but i am no expert so i couldn't make it work
is it a problem with the declared variable not being populated from the "NEW" record or am i executing the select statement wrong ?
EDIT : tl;dr for my problem, I would like to update a table in Database2 whenever the same table (that had the same structre) is altered from Database1, be it added column or changed column, at this point iI'm stuck at the first problem to add the column.
I am logging my tables' structures as strings into a new table and syncing that with Database2 to then have the trigger alter the same altered table from Database1, hope this makes more sense now.
Database1 log_table that logs all my tables' structures:
Database2 log_table_received that is a copy of log_table that executes
the trigger whenever new values are inserted;
Try this syntax:
CREATE OR REPLACE FUNCTION update_table_log_received()
RETURNS TRIGGER AS $$
DECLARE
added_column TEXT;
target_table_name TEXT;
old_column text;
BEGIN
-- Check if a new column has been added
IF (TG_OP = 'INSERT') THEN
added_column := new."column_name";
target_table_name := new."table_name";
END IF;
if not exists(select 1 from information_schema."columns" where table_name = target_table_name and column_name = added_column)
then
EXECUTE 'ALTER TABLE items.' || LOWER(target_table_name)|| ' ADD COLUMN ' || LOWER(added_column) || ' VARCHAR(50)';
end if;
RETURN NEW;
END;
$$ LANGUAGE plpgsql;
I tried on my DB this is works. You can change some details yourself.
Fixed; Question should have been :
How to select tables & table columns inside function in postgresql.
References:
How to add column if not exists on PostgreSQL?
How to check if a table exists in a given schema
How to get a list column names and datatypes of a table in PostgreSQL?
Basically information_schema can only be accessed by owner meaning the user or (i) see the result when i query it but it returns FALSE when executed inside a script more details here :
https://stackoverflow.com/a/24089729/15170264
Full trigger after fix with CTE to query the pg_catalog also added ADD COLUMN IF NOT EXISTS in my Execute query just to be safe
CREATE OR REPLACE FUNCTION update_table_log_received()
RETURNS TRIGGER AS $$
DECLARE
added_column TEXT;
target_table_name TEXT;
old_column varchar;
old_table varchar;
BEGIN
-- Check if a new column has been added
IF (TG_OP = 'INSERT') THEN
added_column := NEW."COLUMN_NAME";
target_table_name := NEW."TABLE_NAME";
END IF;
/*
* --------------- --CTE to find Columns of table "Target_table_name" from pg_catalog
*/
WITH cte_tables AS (
SELECT
pg_attribute.attname AS column_name,
pg_catalog.format_type(pg_attribute.atttypid, pg_attribute.atttypmod) AS data_type
FROM
pg_catalog.pg_attribute
INNER JOIN
pg_catalog.pg_class ON pg_class.oid = pg_attribute.attrelid
INNER JOIN
pg_catalog.pg_namespace ON pg_namespace.oid = pg_class.relnamespace
WHERE
pg_attribute.attnum > 0
AND NOT pg_attribute.attisdropped
AND pg_namespace.nspname = 'items'
AND pg_class.relname = 'trace'
ORDER BY
attnum ASC
)
select column_name into old_column from cte_tables where
column_name=LOWER(added_column);
if (old_column is null ) then
-- Add the new column to the target table
old_column := added_column;
EXECUTE 'ALTER TABLE items.' || LOWER(target_table_name)|| ' ADD COLUMN IF NOT EXISTS ' || LOWER(added_column) || ' VARCHAR(50)';
else
old_column := added_column || 'already exists ! ';
END IF;
RETURN NEW;
END;
$$ LANGUAGE plpgsql;
create TRIGGER update_table_log_received_trigger
AFTER INSERT
ON items."TABLE_LOG_RECEIVED"
FOR EACH ROW
EXECUTE FUNCTION update_table_log_received();
Variable old_column stores the else condition message but i do not return it, would have if it was a simple function.

PostgreSQL PK sequence and Auto incrment problem after moving exisitng MS SQL DB to Postgres [duplicate]

I ran into the problem that my primary key sequence is not in sync with my table rows.
That is, when I insert a new row I get a duplicate key error because the sequence implied in the serial datatype returns a number that already exists.
It seems to be caused by import/restores not maintaining the sequence properly.
-- Login to psql and run the following
-- What is the result?
SELECT MAX(id) FROM your_table;
-- Then run...
-- This should be higher than the last result.
SELECT nextval('your_table_id_seq');
-- If it's not higher... run this set the sequence last to your highest id.
-- (wise to run a quick pg_dump first...)
BEGIN;
-- protect against concurrent inserts while you update the counter
LOCK TABLE your_table IN EXCLUSIVE MODE;
-- Update the sequence
SELECT setval('your_table_id_seq', COALESCE((SELECT MAX(id)+1 FROM your_table), 1), false);
COMMIT;
Source - Ruby Forum
pg_get_serial_sequence can be used to avoid any incorrect assumptions about the sequence name. This resets the sequence in one shot:
SELECT pg_catalog.setval(pg_get_serial_sequence('table_name', 'id'), (SELECT MAX(id) FROM table_name)+1);
Or more concisely:
SELECT pg_catalog.setval(pg_get_serial_sequence('table_name', 'id'), MAX(id)) FROM table_name;
However this form can't handle empty tables correctly, since max(id) is null, and neither can you setval 0 because it would be out of range of the sequence. One workaround for this is to resort to the ALTER SEQUENCE syntax i.e.
ALTER SEQUENCE table_name_id_seq RESTART WITH 1;
ALTER SEQUENCE table_name_id_seq RESTART; -- 8.4 or higher
But ALTER SEQUENCE is of limited use because the sequence name and restart value cannot be expressions.
It seems the best all-purpose solution is to call setval with false as the 3rd parameter, allowing us to specify the "next value to use":
SELECT setval(pg_get_serial_sequence('t1', 'id'), coalesce(max(id),0) + 1, false) FROM t1;
This ticks all my boxes:
avoids hard-coding the actual sequence name
handles empty tables correctly
handles tables with existing data, and does not leave a
hole in the sequence
Finally, note that pg_get_serial_sequence only works if the sequence is owned by the column. This will be the case if the incrementing column was defined as a serial type, however if the sequence was added manually it is necessary to ensure ALTER SEQUENCE .. OWNED BY is also performed.
i.e. if serial type was used for table creation, this should all work:
CREATE TABLE t1 (
id serial,
name varchar(20)
);
SELECT pg_get_serial_sequence('t1', 'id'); -- returns 't1_id_seq'
-- reset the sequence, regardless whether table has rows or not:
SELECT setval(pg_get_serial_sequence('t1', 'id'), coalesce(max(id),0) + 1, false) FROM t1;
But if sequences were added manually:
CREATE TABLE t2 (
id integer NOT NULL,
name varchar(20)
);
CREATE SEQUENCE t2_custom_id_seq
START WITH 1
INCREMENT BY 1
NO MINVALUE
NO MAXVALUE
CACHE 1;
ALTER TABLE t2 ALTER COLUMN id SET DEFAULT nextval('t2_custom_id_seq'::regclass);
ALTER SEQUENCE t2_custom_id_seq OWNED BY t2.id; -- required for pg_get_serial_sequence
SELECT pg_get_serial_sequence('t2', 'id'); -- returns 't2_custom_id_seq'
-- reset the sequence, regardless whether table has rows or not:
SELECT setval(pg_get_serial_sequence('t2', 'id'), coalesce(max(id),0) + 1, false) FROM t1;
The shortest and fastest way
SELECT setval('tbl_tbl_id_seq', max(tbl_id)) FROM tbl;
tbl_id being the serial or IDENTITY column of table tbl, drawing from the sequence tbl_tbl_id_seq (resulting default name). See:
Auto increment table column
If you don't know the name of the attached sequence (which doesn't have to be in default form), use pg_get_serial_sequence() (works for IDENTITY, too):
SELECT setval(pg_get_serial_sequence('tbl', 'tbl_id'), max(tbl_id)) FROM tbl;
There is no off-by-one error here. The manual:
The two-parameter form sets the sequence's last_value field to the
specified value and sets its is_called field to true, meaning that the
next nextval will advance the sequence before returning a value.
Bold emphasis mine.
If the table can be empty, and to actually start from 1 in this case:
SELECT setval(pg_get_serial_sequence('tbl', 'tbl_id')
, COALESCE(max(tbl_id) + 1, 1)
, false)
FROM tbl;
We can't just use the 2-parameter form and start with 0 because the lower bound of sequences is 1 by default (unless customized).
Safe under concurrent write load
To also defend against concurrent sequence activity or writes, lock the table in SHARE mode. It keeps concurrent transactions from writing a higher number (or anything at all).
To also take clients into account that may have fetched sequence numbers in advance without any locks on the main table, yet (can happen in certain setups), only increase the current value of the sequence, never decrease it. That may seem paranoid, but that's in accord with the nature of sequences and defending against concurrency issues.
BEGIN;
LOCK TABLE tbl IN SHARE MODE;
SELECT setval('tbl_tbl_id_seq', max(tbl_id))
FROM tbl
HAVING max(tbl_id) > (SELECT last_value FROM tbl_tbl_id_seq); -- prevent lower number
COMMIT;
SHARE mode is strong enough for the purpose. The manual:
This mode protects a table against concurrent data changes.
It conflicts with ROW EXCLUSIVE mode.
The commands UPDATE, DELETE, and INSERT acquire this lock mode on the target table.
This will reset all sequences from public making no assumptions about table or column names. Tested on version 8.4
CREATE OR REPLACE FUNCTION "reset_sequence" (tablename text, columnname text, sequence_name text)
RETURNS "pg_catalog"."void" AS
$body$
DECLARE
BEGIN
EXECUTE 'SELECT setval( ''' || sequence_name || ''', ' || '(SELECT MAX(' || columnname ||
') FROM ' || tablename || ')' || '+1)';
END;
$body$ LANGUAGE 'plpgsql';
SELECT table_name || '_' || column_name || '_seq',
reset_sequence(table_name, column_name, table_name || '_' || column_name || '_seq')
FROM information_schema.columns where column_default like 'nextval%';
ALTER SEQUENCE sequence_name RESTART WITH (SELECT max(id) FROM table_name);
Doesn't work.
Copied from #tardate answer:
SELECT setval(pg_get_serial_sequence('table_name', 'id'), MAX(id)) FROM table_name;
In the example below, the table name is users and the schema name is public (default schema), replace it according to your needs.
1. Check the max id:
SELECT MAX(id) FROM public.users;
2. Check the next value:
SELECT nextval('public."users_id_seq"');
3. If the next value is lower than the max id, reset it:
SELECT setval('public."users_id_seq"',
(SELECT MAX(id) FROM public.users)
);
Note:
nextval() will increment the sequence before returning the current value while currval() would just return the current value, as documented here.
This command for only change auto generated key sequence value in postgresql
ALTER SEQUENCE "your_sequence_name" RESTART WITH 0;
In place of zero you can put any number from which you want to restart sequence.
default sequence name will "TableName_FieldName_seq". For example, if your table name is "MyTable" and your field name is "MyID", then your sequence name will be "MyTable_MyID_seq".
This is answer is same as #murugesanponappan's answer, but there is a syntax error in his solution. you can not use sub query (select max()...) in alter command. So that either you have to use fixed numeric value or you need to use a variable in place of sub query.
Reset all sequences, no assumptions about names except that the primary key of each table is "id":
CREATE OR REPLACE FUNCTION "reset_sequence" (tablename text, columnname text)
RETURNS "pg_catalog"."void" AS
$body$
DECLARE
BEGIN
EXECUTE 'SELECT setval( pg_get_serial_sequence(''' || tablename || ''', ''' || columnname || '''),
(SELECT COALESCE(MAX(id)+1,1) FROM ' || tablename || '), false)';
END;
$body$ LANGUAGE 'plpgsql';
select table_name || '_' || column_name || '_seq', reset_sequence(table_name, column_name) from information_schema.columns where column_default like 'nextval%';
These functions are fraught with perils when sequence names, column names, table names or schema names have funny characters such as spaces, punctuation marks, and the like. I have written this:
CREATE OR REPLACE FUNCTION sequence_max_value(oid) RETURNS bigint
VOLATILE STRICT LANGUAGE plpgsql AS $$
DECLARE
tabrelid oid;
colname name;
r record;
newmax bigint;
BEGIN
FOR tabrelid, colname IN SELECT attrelid, attname
FROM pg_attribute
WHERE (attrelid, attnum) IN (
SELECT adrelid::regclass,adnum
FROM pg_attrdef
WHERE oid IN (SELECT objid
FROM pg_depend
WHERE refobjid = $1
AND classid = 'pg_attrdef'::regclass
)
) LOOP
FOR r IN EXECUTE 'SELECT max(' || quote_ident(colname) || ') FROM ' || tabrelid::regclass LOOP
IF newmax IS NULL OR r.max > newmax THEN
newmax := r.max;
END IF;
END LOOP;
END LOOP;
RETURN newmax;
END; $$ ;
You can call it for a single sequence by passing it the OID and it will return the highest number used by any table that has the sequence as default; or you can run it with a query like this, to reset all the sequences in your database:
select relname, setval(oid, sequence_max_value(oid))
from pg_class
where relkind = 'S';
Using a different qual you can reset only the sequence in a certain schema, and so on. For example, if you want to adjust sequences in the "public" schema:
select relname, setval(pg_class.oid, sequence_max_value(pg_class.oid))
from pg_class, pg_namespace
where pg_class.relnamespace = pg_namespace.oid and
nspname = 'public' and
relkind = 'S';
Note that due to how setval() works, you don't need to add 1 to the result.
As a closing note, I have to warn that some databases seem to have defaults linking to sequences in ways that do not let the system catalogs have full information of them. This happens when you see things like this in psql's \d:
alvherre=# \d baz
Tabla «public.baz»
Columna | Tipo | Modificadores
---------+---------+------------------------------------------------
a | integer | default nextval(('foo_a_seq'::text)::regclass)
Note that the nextval() call in that default clause has a ::text cast in addition to the ::regclass cast. I think this is due to databases being pg_dump'ed from old PostgreSQL versions. What will happen is that the function sequence_max_value() above will ignore such a table. To fix the problem, you can redefine the DEFAULT clause to refer to the sequence directly without the cast:
alvherre=# alter table baz alter a set default nextval('foo_a_seq');
ALTER TABLE
Then psql displays it properly:
alvherre=# \d baz
Tabla «public.baz»
Columna | Tipo | Modificadores
---------+---------+----------------------------------------
a | integer | default nextval('foo_a_seq'::regclass)
As soon as you've fixed that, the function works correctly for this table as well as all others that might use the same sequence.
I suggest this solution found on postgres wiki. It updates all sequences of your tables.
SELECT 'SELECT SETVAL(' ||
quote_literal(quote_ident(PGT.schemaname) || '.' || quote_ident(S.relname)) ||
', COALESCE(MAX(' ||quote_ident(C.attname)|| '), 1) ) FROM ' ||
quote_ident(PGT.schemaname)|| '.'||quote_ident(T.relname)|| ';'
FROM pg_class AS S,
pg_depend AS D,
pg_class AS T,
pg_attribute AS C,
pg_tables AS PGT
WHERE S.relkind = 'S'
AND S.oid = D.objid
AND D.refobjid = T.oid
AND D.refobjid = C.attrelid
AND D.refobjsubid = C.attnum
AND T.relname = PGT.tablename
ORDER BY S.relname;
How to use(from postgres wiki):
Save this to a file, say 'reset.sql'
Run the file and save its output in a way that doesn't include the usual headers, then run that output. Example:
Example:
psql -Atq -f reset.sql -o temp
psql -f temp
rm temp
Original article(also with fix for sequence ownership) here
Yet another plpgsql - resets only if max(att) > then lastval
do --check seq not in sync
$$
declare
_r record;
_i bigint;
_m bigint;
begin
for _r in (
SELECT relname,nspname,d.refobjid::regclass, a.attname, refobjid
FROM pg_depend d
JOIN pg_attribute a ON a.attrelid = d.refobjid AND a.attnum = d.refobjsubid
JOIN pg_class r on r.oid = objid
JOIN pg_namespace n on n.oid = relnamespace
WHERE d.refobjsubid > 0 and relkind = 'S'
) loop
execute format('select last_value from %I.%I',_r.nspname,_r.relname) into _i;
execute format('select max(%I) from %s',_r.attname,_r.refobjid) into _m;
if coalesce(_m,0) > _i then
raise info '%',concat('changed: ',_r.nspname,'.',_r.relname,' from:',_i,' to:',_m);
execute format('alter sequence %I.%I restart with %s',_r.nspname,_r.relname,_m+1);
end if;
end loop;
end;
$$
;
also commenting the line --execute format('alter sequence will give the list, not actually resetting the value
Reset all sequence from public
CREATE OR REPLACE FUNCTION "reset_sequence" (tablename text) RETURNS "pg_catalog"."void" AS
$body$
DECLARE
BEGIN
EXECUTE 'SELECT setval( '''
|| tablename
|| '_id_seq'', '
|| '(SELECT id + 1 FROM "'
|| tablename
|| '" ORDER BY id DESC LIMIT 1), false)';
END;
$body$ LANGUAGE 'plpgsql';
select sequence_name, reset_sequence(split_part(sequence_name, '_id_seq',1)) from information_schema.sequences
where sequence_schema='public';
This issue happens with me when using entity framework to create the database and then seed the database with initial data, this makes the sequence mismatch.
I Solved it by Creating a script to run after seeding the database:
DO
$do$
DECLARE tablename text;
BEGIN
-- change the where statments to include or exclude whatever tables you need
FOR tablename IN SELECT table_name FROM information_schema.tables WHERE table_schema='public' AND table_type='BASE TABLE' AND table_name != '__EFMigrationsHistory'
LOOP
EXECUTE format('SELECT setval(pg_get_serial_sequence(''"%s"'', ''Id''), (SELECT MAX("Id") + 1 from "%s"))', tablename, tablename);
END LOOP;
END
$do$
Some really hardcore answers here, I'm assuming it used to be really bad at around the time when this has been asked, since a lot of answers from here don't works for version 9.3. The documentation since version 8.0 provides an answer to this very question:
SELECT setval('serial', max(id)) FROM distributors;
Also, if you need to take care of case-sensitive sequence names, that's how you do it:
SELECT setval('"Serial"', max(id)) FROM distributors;
My version use the first one, with some error checking...
BEGIN;
CREATE OR REPLACE FUNCTION reset_sequence(_table_schema text, _tablename text, _columnname text, _sequence_name text)
RETURNS pg_catalog.void AS
$BODY$
DECLARE
BEGIN
PERFORM 1
FROM information_schema.sequences
WHERE
sequence_schema = _table_schema AND
sequence_name = _sequence_name;
IF FOUND THEN
EXECUTE 'SELECT setval( ''' || _table_schema || '.' || _sequence_name || ''', ' || '(SELECT MAX(' || _columnname || ') FROM ' || _table_schema || '.' || _tablename || ')' || '+1)';
ELSE
RAISE WARNING 'SEQUENCE NOT UPDATED ON %.%', _tablename, _columnname;
END IF;
END;
$BODY$
LANGUAGE 'plpgsql';
SELECT reset_sequence(table_schema, table_name, column_name, table_name || '_' || column_name || '_seq')
FROM information_schema.columns
WHERE column_default LIKE 'nextval%';
DROP FUNCTION reset_sequence(_table_schema text, _tablename text, _columnname text, _sequence_name text) ;
COMMIT;
Putting it all together
CREATE OR REPLACE FUNCTION "reset_sequence" (tablename text)
RETURNS "pg_catalog"."void" AS
$body$
DECLARE
BEGIN
EXECUTE 'SELECT setval( pg_get_serial_sequence(''' || tablename || ''', ''id''),
(SELECT COALESCE(MAX(id)+1,1) FROM ' || tablename || '), false)';
END;
$body$ LANGUAGE 'plpgsql';
will fix 'id' sequence of the given table (as usually necessary with django for instance).
Recheck all sequence in public schema function
CREATE OR REPLACE FUNCTION public.recheck_sequence (
)
RETURNS void AS
$body$
DECLARE
_table_name VARCHAR;
_column_name VARCHAR;
_sequence_name VARCHAR;
BEGIN
FOR _table_name IN SELECT tablename FROM pg_catalog.pg_tables WHERE schemaname = 'public' LOOP
FOR _column_name IN SELECT column_name FROM information_schema.columns WHERE table_name = _table_name LOOP
SELECT pg_get_serial_sequence(_table_name, _column_name) INTO _sequence_name;
IF _sequence_name IS NOT NULL THEN
EXECUTE 'SELECT setval('''||_sequence_name||''', COALESCE((SELECT MAX('||quote_ident(_column_name)||')+1 FROM '||quote_ident(_table_name)||'), 1), FALSE);';
END IF;
END LOOP;
END LOOP;
END;
$body$
LANGUAGE 'plpgsql'
VOLATILE
CALLED ON NULL INPUT
SECURITY INVOKER
COST 100;
before I had not tried yet the code : in the following I post
the version for the sql-code for both Klaus and user457226 solutions
which worked on my pc [Postgres 8.3], with just some little adjustements
for the Klaus one and of my version for the user457226 one.
Klaus solution :
drop function IF EXISTS rebuilt_sequences() RESTRICT;
CREATE OR REPLACE FUNCTION rebuilt_sequences() RETURNS integer as
$body$
DECLARE sequencedefs RECORD; c integer ;
BEGIN
FOR sequencedefs IN Select
constraint_column_usage.table_name as tablename,
constraint_column_usage.table_name as tablename,
constraint_column_usage.column_name as columnname,
replace(replace(columns.column_default,'''::regclass)',''),'nextval(''','') as sequencename
from information_schema.constraint_column_usage, information_schema.columns
where constraint_column_usage.table_schema ='public' AND
columns.table_schema = 'public' AND columns.table_name=constraint_column_usage.table_name
AND constraint_column_usage.column_name = columns.column_name
AND columns.column_default is not null
LOOP
EXECUTE 'select max('||sequencedefs.columnname||') from ' || sequencedefs.tablename INTO c;
IF c is null THEN c = 0; END IF;
IF c is not null THEN c = c+ 1; END IF;
EXECUTE 'alter sequence ' || sequencedefs.sequencename ||' restart with ' || c;
END LOOP;
RETURN 1; END;
$body$ LANGUAGE plpgsql;
select rebuilt_sequences();
user457226 solution :
--drop function IF EXISTS reset_sequence (text,text) RESTRICT;
CREATE OR REPLACE FUNCTION "reset_sequence" (tablename text,columnname text) RETURNS bigint --"pg_catalog"."void"
AS
$body$
DECLARE seqname character varying;
c integer;
BEGIN
select tablename || '_' || columnname || '_seq' into seqname;
EXECUTE 'SELECT max("' || columnname || '") FROM "' || tablename || '"' into c;
if c is null then c = 0; end if;
c = c+1; --because of substitution of setval with "alter sequence"
--EXECUTE 'SELECT setval( "' || seqname || '", ' || cast(c as character varying) || ', false)'; DOES NOT WORK!!!
EXECUTE 'alter sequence ' || seqname ||' restart with ' || cast(c as character varying);
RETURN nextval(seqname)-1;
END;
$body$ LANGUAGE 'plpgsql';
select sequence_name, PG_CLASS.relname, PG_ATTRIBUTE.attname,
reset_sequence(PG_CLASS.relname,PG_ATTRIBUTE.attname)
from PG_CLASS
join PG_ATTRIBUTE on PG_ATTRIBUTE.attrelid = PG_CLASS.oid
join information_schema.sequences
on information_schema.sequences.sequence_name = PG_CLASS.relname || '_' || PG_ATTRIBUTE.attname || '_seq'
where sequence_schema='public';
This answer is a copy from mauro.
drop function IF EXISTS rebuilt_sequences() RESTRICT;
CREATE OR REPLACE FUNCTION rebuilt_sequences() RETURNS integer as
$body$
DECLARE sequencedefs RECORD; c integer ;
BEGIN
FOR sequencedefs IN Select
DISTINCT(constraint_column_usage.table_name) as tablename,
constraint_column_usage.column_name as columnname,
replace(replace(columns.column_default,'''::regclass)',''),'nextval(''','') as sequencename
from information_schema.constraint_column_usage, information_schema.columns
where constraint_column_usage.table_schema ='public' AND
columns.table_schema = 'public' AND columns.table_name=constraint_column_usage.table_name
AND constraint_column_usage.column_name = columns.column_name
AND columns.column_default is not null
ORDER BY sequencename
LOOP
EXECUTE 'select max('||sequencedefs.columnname||') from ' || sequencedefs.tablename INTO c;
IF c is null THEN c = 0; END IF;
IF c is not null THEN c = c+ 1; END IF;
EXECUTE 'alter sequence ' || sequencedefs.sequencename ||' minvalue '||c ||' start ' || c ||' restart with ' || c;
END LOOP;
RETURN 1; END;
$body$ LANGUAGE plpgsql;
select rebuilt_sequences();
If you see this error when you are loading custom SQL data for initialization, another way to avoid this is:
Instead of writing:
INSERT INTO book (id, name, price) VALUES (1 , 'Alchemist' , 10),
Remove the id (primary key) from initial data
INSERT INTO book (name, price) VALUES ('Alchemist' , 10),
This keeps the Postgres sequence in sync !
To restart all sequence to 1 use:
-- Create Function
CREATE OR REPLACE FUNCTION "sy_restart_seq_to_1" (
relname TEXT
)
RETURNS "pg_catalog"."void" AS
$BODY$
DECLARE
BEGIN
EXECUTE 'ALTER SEQUENCE '||relname||' RESTART WITH 1;';
END;
$BODY$
LANGUAGE 'plpgsql';
-- Use Function
SELECT
relname
,sy_restart_seq_to_1(relname)
FROM pg_class
WHERE relkind = 'S';
The Klaus answer is the most useful, execpt for a little miss : you
have to add DISTINCT in select statement.
However, if you are sure that no table+column names can be equivalent
for two different tables, you can also use :
select sequence_name, --PG_CLASS.relname, PG_ATTRIBUTE.attname
reset_sequence(split_part(sequence_name, '_id_seq',1))
from PG_CLASS
join PG_ATTRIBUTE on PG_ATTRIBUTE.attrelid = PG_CLASS.oid
join information_schema.sequences
on information_schema.sequences.sequence_name = PG_CLASS.relname || '_' || PG_ATTRIBUTE.attname
where sequence_schema='public';
which is an extension of user457226 solution for the case when
some interested column name is not 'ID'.
I spent an hour trying to get djsnowsill's answer to work with a database using Mixed Case tables and columns, then finally stumbled upon the solution thanks to a comment from Manuel Darveau, but I thought I could make it a bit clearer for everyone:
CREATE OR REPLACE FUNCTION "reset_sequence" (tablename text, columnname text)
RETURNS "pg_catalog"."void" AS
$body$
DECLARE
BEGIN
EXECUTE format('SELECT setval(pg_get_serial_sequence(''%1$I'', %2$L),
(SELECT COALESCE(MAX(%2$I)+1,1) FROM %1$I), false)',tablename,columnname);
END;
$body$ LANGUAGE 'plpgsql';
SELECT format('%s_%s_seq',table_name,column_name), reset_sequence(table_name,column_name)
FROM information_schema.columns WHERE column_default like 'nextval%';
This has the benefit of:
not assuming ID column is spelled a particular way.
not assuming all tables have a sequence.
working for Mixed Case table/column names.
using format to be more concise.
To explain, the problem was that pg_get_serial_sequence takes strings to work out what you're referring to, so if you do:
"TableName" --it thinks it's a table or column
'TableName' --it thinks it's a string, but makes it lower case
'"TableName"' --it works!
This is achieved using ''%1$I'' in the format string, '' makes an apostrophe 1$ means first arg, and I means in quotes
select 'SELECT SETVAL(' || seq [ 1] || ', COALESCE(MAX('||column_name||')+1, 1) ) FROM '||table_name||';'
from (
SELECT table_name, column_name, column_default, regexp_match(column_default, '''.*''') as seq
from information_schema.columns
where column_default ilike 'nextval%'
) as sequense_query
Just run below command:
SELECT setval('my_table_seq', (SELECT max(id) FROM my_table));
Ugly hack to fix it using some shell magic, not a great solution but might inspire others with similar problems :)
pg_dump -s <DATABASE> | grep 'CREATE TABLE' | awk '{print "SELECT setval(#" $3 "_id_seq#, (SELECT MAX(id) FROM " $3 "));"}' | sed "s/#/'/g" | psql <DATABASE> -f -
A method to update all sequences in your schema that are used as an ID:
DO $$ DECLARE
r RECORD;
BEGIN
FOR r IN (SELECT tablename, pg_get_serial_sequence(tablename, 'id') as sequencename
FROM pg_catalog.pg_tables
WHERE schemaname='YOUR_SCHEMA'
AND tablename IN (SELECT table_name
FROM information_schema.columns
WHERE table_name=tablename and column_name='id')
order by tablename)
LOOP
EXECUTE
'SELECT setval(''' || r.sequencename || ''', COALESCE(MAX(id), 1), MAX(id) IS NOT null)
FROM ' || r.tablename || ';';
END LOOP;
END $$;
So I can tell there aren't enough opinions or reinvented wheels in this thread, so I decided to spice things up.
Below is a procedure that:
is focused (only affects) on sequences that are associated with tables
works for both SERIAL and GENERATED AS IDENTITY columns
works for good_column_names and "BAD_column_123" names
automatically assigns the respective sequences' defined start value if the table is empty
allows for a specific sequences to be affected only (in schema.table.column notation)
has a preview mode
CREATE OR REPLACE PROCEDURE pg_reset_all_table_sequences(
IN commit_mode BOOLEAN DEFAULT FALSE
, IN mask_in TEXT DEFAULT NULL
) AS
$$
DECLARE
sql_reset TEXT;
each_sec RECORD;
new_val TEXT;
BEGIN
sql_reset :=
$sql$
SELECT setval(pg_get_serial_sequence('%1$s.%2$s', '%3$s'), coalesce(max("%3$s"), %4$s), false) FROM %1$s.%2$s;
$sql$
;
FOR each_sec IN (
SELECT
quote_ident(table_schema) as table_schema
, quote_ident(table_name) as table_name
, column_name
, coalesce(identity_start::INT, seqstart) as min_val
FROM information_schema.columns
JOIN pg_sequence ON seqrelid = pg_get_serial_sequence(quote_ident(table_schema)||'.'||quote_ident(table_name) , column_name)::regclass
WHERE
(is_identity::boolean OR column_default LIKE 'nextval%') -- catches both SERIAL and IDENTITY sequences
-- mask on column address (schema.table.column) if supplied
AND coalesce( table_schema||'.'||table_name||'.'||column_name = mask_in, TRUE )
)
LOOP
IF commit_mode THEN
EXECUTE format(sql_reset, each_sec.table_schema, each_sec.table_name, each_sec.column_name, each_sec.min_val) INTO new_val;
RAISE INFO 'Resetting sequence for: %.% (%) to %'
, each_sec.table_schema
, each_sec.table_name
, each_sec.column_name
, new_val
;
ELSE
RAISE INFO 'Sequence found for resetting: %.% (%)'
, each_sec.table_schema
, each_sec.table_name
, each_sec.column_name
;
END IF
;
END LOOP;
END
$$
LANGUAGE plpgsql
;
to preview:
call pg_reset_all_table_sequences();
to commit:
call pg_reset_all_table_sequences(true);
to specify only your target table:
call pg_reset_all_table_sequences('schema.table.column');
Try reindex.
UPDATE: As pointed out in the comments, this was in reply to the original question.
There are a lot of good answers here. I had the same need after reloading my Django database.
But I needed:
All in one Function
Could fix one or more schemas at a time
Could fix all or just one table at a time
Also wanted a nice way to see exactly what had changed, or not changed
This seems very similar need to what the original ask was for.
Thanks to Baldiry and Mauro got me on the right track.
drop function IF EXISTS reset_sequences(text[], text) RESTRICT;
CREATE OR REPLACE FUNCTION reset_sequences(
in_schema_name_list text[] = '{"django", "dbaas", "metrics", "monitor", "runner", "db_counts"}',
in_table_name text = '%') RETURNS text[] as
$body$
DECLARE changed_seqs text[];
DECLARE sequence_defs RECORD; c integer ;
BEGIN
FOR sequence_defs IN
select
DISTINCT(ccu.table_name) as table_name,
ccu.column_name as column_name,
replace(replace(c.column_default,'''::regclass)',''),'nextval(''','') as sequence_name
from information_schema.constraint_column_usage ccu,
information_schema.columns c
where ccu.table_schema = ANY(in_schema_name_list)
and ccu.table_schema = c.table_schema
AND c.table_name = ccu.table_name
and c.table_name like in_table_name
AND ccu.column_name = c.column_name
AND c.column_default is not null
ORDER BY sequence_name
LOOP
EXECUTE 'select max(' || sequence_defs.column_name || ') from ' || sequence_defs.table_name INTO c;
IF c is null THEN c = 1; else c = c + 1; END IF;
EXECUTE 'alter sequence ' || sequence_defs.sequence_name || ' restart with ' || c;
changed_seqs = array_append(changed_seqs, 'alter sequence ' || sequence_defs.sequence_name || ' restart with ' || c);
END LOOP;
changed_seqs = array_append(changed_seqs, 'Done');
RETURN changed_seqs;
END
$body$ LANGUAGE plpgsql;
Then to Execute and See the changes run:
select *
from unnest(reset_sequences('{"django", "dbaas", "metrics", "monitor", "runner", "db_counts"}'));
Returns
activity_id_seq restart at 22
api_connection_info_id_seq restart at 4
api_user_id_seq restart at 1
application_contact_id_seq restart at 20

ORACLE SQL: Looping over table

I have a table that contains a list of table names.
I would like to search each of these tables one by one to see if they contain a particular element (the primary key, specified at the start of the script).
I would like to return a list of all of the tables that this element is present in (ideally distinct).
I'm fairly new to this PL/SQL "not just a query" stuff. so i apologise in advance for the attrocious attempt you are about to see, but hopefully it illustrates what i'm going for:
PROCEDURE CHECK_FOR_ELEMENTS
BEGIN
DECLARE
ELEMENT_KEY varchar(5):=X78ehryfk;
RNUM_MAX int :=167;
----create output table for script
create or replace table ALL_TABLES CONTAINING_&ELEMENT_KEY
(ELEMENT_KEY VARCHAR(255),
TABLE_NAME varchar(255))
/
commit;
---begin loop over rnum;
FOR rnum_counter in 1..&RNUM_MAX
LOOP
--define this statement as variable TABLE_NAME_VAR
select table_name from (select * from (select table_name, rownum as rnum
from all_tables
where owner = 'RMS'
and table_name like 'ABC%'
and table_name not like '%STG'
and table_name not like '%BKP'
and num_rows>0
order by num_rows desc)
where rnum = rnum_counter
)INTO TABLE_NAME_VAR
;
----run below to collect row, if it exists, from table being searched
SQL_STMT:='INSERT INTO ALL_TABLES CONTAINING_&ELEMENT_KEY
SELECT distinct key,'||TABLE_NAME_VAR||' as UMF from
'||TABLE_NAME_VAR||
' where key like 'ELEMENT_KEY-%'
execute immediate SQL_STMT;
commit;
---insert row into table created for output
END LOOP
---loop over all tables
END;
The main error message i get is that TABLE_NAME_VAR is not a valid table name within the dynamic SQL statement. I've googled a bit and i now understand you can't use variables to input table names in this way.
Any help is greatly appreciated!
Thankyou!
Here, I tried to clean it up for you. Let me know if you still get errors.
create or replace PROCEDURE CHECK_FOR_ELEMENTS is
ELEMENT_KEY varchar2(14):='X78ehryfk';
RNUM_MAX int :=167;
TABLE_NAME_VAR varchar2(30);
SQL_STMT varchar2(4000);
BEGIN
----create output table for script
begin
execute immediate 'drop table ALL_TABLES_WITH_' || element_key;
exception when others then null;
end;
execute immediate 'create table ALL_TABLES_WITH_' || element_key || '
(ELEMENT_KEY VARCHAR2(255), -- does this need to be 255 characters?
TABLE_NAME varchar2(30))';
--- implicit cursor loop
FOR rnum_row in (select table_name, rownum as rnum
from all_tables
where owner = 'RMS'
and table_name like 'ABC%'
and table_name not like '%STG'
and table_name not like '%BKP'
and num_rows>0
order by num_rows desc)
LOOP
if rnum_row.rnum > RNUM_MAX
then exit;
end if;
TABLE_NAME_VAR := rnum_row.table_name;
----run below to collect row, if it exists, from table being searched
SQL_STMT:='INSERT INTO ALL_TABLES_WITH_' || element_key || '
(ELEMENT_KEY, TABLE_NAME)
SELECT distinct key, :1 as UMF from
'||TABLE_NAME_VAR||
' where key like :2';
execute immediate SQL_STMT using TABLE_NAME_VAR, element_key || '-%';
---insert row into table created for output
END LOOP;
commit;
---loop over all tables
END CHECK_FOR_ELEMENTS;
/

Oracle procedure/function to create a trigger in table

I'm trying to create a procedure that given a table name, it will create a sequence and auto incrementing trigger, all using variables based on the table name.
Code :
CREATE OR REPLACE procedure CREATE_SEQUENTIAL_TR(table_name VARCHAR)
is -- Tried using declare but it wouldn't accept
coluna_cod varchar(100 char);
begin
--Finding the cod column name for this table first
--They start with "PK_CD"
select
COLUMN_NAME
into
coluna_cod
from
ALL_TAB_COLUMNS
where
TABLE_NAME=table_name
and COLUMN_NAME like "PK_CD%";
--Creating the sequence obj
drop sequence "cod" || table_name;
create sequence "cod" || table_name;
--Now creating the trigger
create or replace trigger "cod" || table_name || "tr"
before
UPDATE or INSERT on table_name
for each row
declare
cod number := coluna_cod;
tr_name varchar(100 char) := "cod" || table_name
begin
if UPDATING then
if :new.cod != :old.cod then
:new.cod := :old.cod;
end if;
else -- inserting
:new.cod := tr_name.nextval();
end if;
end;
end;
The complexity of this ended up quite out of the scope of my knowledge.
At the moment it is giving an error on drop sequence "cod" || table_name (Unexpected DROP symbol found) but I'm sure I have made other errors.
Can someone help me figure this logic out?
You can't put DDL statements (like drop or create or alter) directly inside a PL/SQL block. If you want to do DDL inside PL/SQL, you can do an execute immediate:
declare
begin
drop sequence X; -- error
execute immediate 'drop sequence X'; -- works fine
end;
/

Alter each column named 'xxx'

I'm trying to create a PostgreSQL stored procedure that must set default value 'now()' to each columns named 'CreationDate' in every tables.
CREATE OR REPLACE FUNCTION set_creation_date() RETURNS
void AS $$
DECLARE
t pg_tables%ROWTYPE;
BEGIN
FOR t IN SELECT "tablename" FROM pg_tables WHERE "schemaname" = 'public' LOOP
IF EXISTS (select * from information_schema.columns where table_name = t."tablename"
and column_name = 'CreationDate') THEN
EXECUTE FORMAT('ALTER TABLE %I ALTER COLUMN "CreationDate" SET DEFAULT now()', t."tablename");
END IF;
END LOOP;
END;
$$ LANGUAGE plpgsql;
But no columns are affected. What's wrong?
It looks like it's trying to alter t."tablename" every time. Try the following instead:
EXECUTE FORMAT('ALTER TABLE %I ALTER COLUMN "CreationDate" SET DEFAULT now()', t."tablename");
I don't have a PostgreSQL server available to test, so please let me know if the syntax isn't quite right.
I finally resolved. The error was in pg_tables%ROWTYPE: using debugger i realized that the field 'tablename' doesn't exist, so i declared 't' as text.
I created a function with parameters, where you have to pass schema name and column name. I ll post it here for anyone who ll need it
DROP FUNCTION IF EXISTS set_creation_date(character varying, character varying);
CREATE OR REPLACE FUNCTION set_creation_date(_schema_name character varying, _column_date character varying)
RETURNS void AS
$BODY$
DECLARE
t TEXT;
BEGIN
FOR t IN SELECT "tablename" FROM pg_tables WHERE "schemaname" = _schema_name LOOP
IF EXISTS (select * from information_schema.columns where table_name = t and column_name = _column_date) THEN
EXECUTE FORMAT('ALTER TABLE %I ALTER COLUMN %I SET DEFAULT now()', t, _column_date);
END IF;
END LOOP;
END;
$BODY$
LANGUAGE plpgsql;