I'm trying to migrate my sqlite database to postgresql.
I'm new to postgresql but stuck on this simple issue.
I fist used the pgloader tool to migrate to postgresql and have a working database. I see it created the table this way:
CREATE TABLE "AOrder"
(
"OrderNumber" bigserial NOT NULL,
"BuyerName" text,
etc
)
WITH (
OIDS=FALSE
);
ALTER TABLE "AOrder"
OWNER TO postgres;
Using pgadmin3 if I run the SQL query:
select
*
from AOrder
This returns the column names plus all the data as expected.
However, the following:
select
*
from "AOrder"
This returns just the column names and no data. Where's the data?
So it's not a problem with capitalization. Is there a setting in postgresql that is making this happen?
(This is ultimately the root problem for me since I am then using Sqlachemy which inserts the double quotes in queries. I could not figure out a way to change that behavior.)
Thanks!
Related
I'm coming from a background in SQL Server where I would create temp tables using the:
select id
into #test
from table A
I've just moved into a PostGresql environment and I was hoping I could do the same, but I'm getting a syntax error. I did a search and it seems like you have to do a Create Table statement.
Is it not possible to easily create temp tables in Postgres?
Postgres supports SELECT INTO, so this should work fine:
SELECT id
INTO TEMP TABLE test
FROM a
You can also use CREATE TABLE AS:
CREATE TEMP TABLE test AS
SELECT id FROM a
This version is generally preferred, as the CREATE statement provides additional options, and can also be used in PL/pgSQL functions (where the SELECT INTO syntax has been hijacked for variable assignment).
Postgresql lost the autoincrement feature after a restore. My database was created on Windows 10 (v 10.1) and I restored it to Postgresql on Ubuntu (v 9.6). Now that I posted the question I saw that the versions are different. I didn't use any obscure feature, only tables, functions, and columns with serials. Also, the restore process didn't complain about anything. I checked the dump options but I couldn't find anything that caused the problem.
With Pgadmin right-clicking the table > scripts > create a script on my original table gives this:
CREATE TABLE public.produto
(
produto_id integer NOT NULL DEFAULT nextval('produto_produto_id_seq'::regclass),
...
);
In my server, the restored database. It seems it lost the feature.
CREATE TABLE public.produto
(
produto_id integer NOT NULL,
...
);
You didn't check for errors during restore of the database; there should have been a few.
A dump of a table like yours will look like this in PostgreSQL v10 (this is 10.3 and it looks slightly different in 10.1, but that's irrelevant to this case):
CREATE TABLE public.produto (
produto_id integer NOT NULL
);
ALTER TABLE public.produto OWNER TO laurenz;
CREATE SEQUENCE public.produto_produto_id_seq
AS integer
START WITH 1
INCREMENT BY 1
NO MINVALUE
NO MAXVALUE
CACHE 1;
ALTER TABLE public.produto_produto_id_seq OWNER TO laurenz;
ALTER SEQUENCE public.produto_produto_id_seq
OWNED BY public.produto.produto_id;
ALTER TABLE ONLY public.produto
ALTER COLUMN produto_id
SET DEFAULT nextval('public.produto_produto_id_seq'::regclass);
Now the problem is that AS integer was introduced to CREATE SEQUENCE in PostgreSQL v10, so that statement will fail with a syntax error in 9.6.
What is the consequence?
The table is created like in the first statement.
The third statement creating the sequence fails.
All the following statements that require the sequence will also fail.
Note: It is not supported to downgrade PostgeSQL with dump and restore.
The solution is to manually edit the dump until it works, in particular you'll have to remove the AS integer or AS bigint clause in CREATE SEQUENCE.
I use knex to create a postgres table as following:
knex.schema.createTable('users', table => {
table.bigIncrements('user_id');
....
})
But after the table was created, the column user_id is a integer not the serial as expected.
The sql get by the pgAdmin is as following:
CREATE TABLE public.users
(
user_id bigint NOT NULL DEFAULT nextval('users_user_id_seq'::regclass),
....
)
And the consequence is that when I do insert statement, the user_id won't auto increment as expected.
Any gives?
====================
Currently I just changed to mysql connection, and the inserting works well. But if I changed the database back to postgresql, then inserting would fail due to the duplication of user_id. The code can be found here: https://github.com/buzz-buzz/buzz-service
serial and bigserial are not real types they are just shorthand for what pgAdmin is showing.
You will also find that a sequence has been created with the name users_user_id_seq when you look under sequences in pgAdmin.
I've got a table with 4 rows in it in a non-production database used for development. There are 2 varchar columns that I want to convert to bytea. I don't care about the contents so I could of course drop the columns and then add them back, but I became confused when I tried to just change the type:
alter table whatever
alter column col_1 set data type bytea using null,
alter column col_2 set data type bytea using null;
When I try that, the psql client just hangs. By that I mean that it just sits there giving no feedback until I eventually hit ^C and it aborts. I've tried that with a little test table and it works fine, but for some reason it doesn't work on the real table (which, really, is also just a "little test table").
The using clause doesn't seem to make a difference one way or the other; I can leave it out or give other values, and the command does the same thing.
I don't get an error, I just don't get anything. Is that what I should expect?
I'm on 9.1 on ubuntu 14.10 if it matters.
I don't care about the contents
In that case, this works on an empty table:
ALTER TABLE tablename
ALTER COLUMN colname TYPE bytea USING colname::bytea
;
Simple:
Get the active locks from pg_locks:
select t.relname,l.locktype,page,virtualtransaction,pid,mode,granted from pg_locks l, pg_stat_all_tables t where l.relation=t.relid order by relation asc;
Copy the pid(ex: 14210) from above result and substitute in the below command.
SELECT pg_terminate_backend('14210')
Here is some SQL for PostgreSQL (I know it's a silly query; I've boiled the original query down to the simplest broken code):
CREATE TABLE entity (
id SERIAL PRIMARY KEY
);
WITH new_entity
AS (INSERT INTO entity DEFAULT VALUES
RETURNING id
)
SELECT id FROM new_entity;
Here it is running on PostgreSQL 9.1:
psql:../sandbox/test.sql:3: NOTICE: CREATE TABLE will create implicit sequence "entity_id_seq" for serial column "entity.id"
psql:../sandbox/test.sql:3: NOTICE: CREATE TABLE / PRIMARY KEY will create implicit index "entity_pkey" for table "entity"
CREATE TABLE
id
----
1
(1 row)
Here it is not running on PostgreSQL 8.4:
psql:../sandbox/test.sql:3: NOTICE: CREATE TABLE will create implicit sequence "entity_id_seq" for serial column "entity.id"
psql:../sandbox/test.sql:3: NOTICE: CREATE TABLE / PRIMARY KEY will create implicit index "entity_pkey" for table "entity"
CREATE TABLE
psql:../sandbox/test.sql:9: ERROR: syntax error at or near "INSERT"
LINE 2: AS (INSERT INTO entity DEFAULT VALUES
Obviously, the table creation goes fine in both cases, but it wipes out on the second query in PostgreSQL 8.4. From this error message I am unable to gather exactly what the problem is. I don't know what it is that 9.1 has and 8.4 doesn't have that could result in this syntax error. It's hilariously hard to google it. I am approaching the level of desperation required to trawl through the pages of PostgreSQL release notes between 8.4 and 9.1 and finding out if anything related to WITH … AS or INSERT … RETURNING was changed or added, but before I go there I am hoping one of you has the experience and/or godly google-fu to help me out here.
Data-modifying statements in WITH were introduced in Postgres 9.1