I have two tables master / detail their DDL are:
Table1:
tbl1_id integer,
tbl1_sm_id integer,
tbl1_name varchar(30)
table2:
tbl2_id integer,
tbl1_id integer,
tbl2_name varchar(30)
table2.tbl1_id is the foreign key between the two tables, tbl1_id and tbl2_id are generated automatically from triggers.
I need to copy all records from these two tables where tbl1_sm_id = 2 into new value where tbl1_sm_id = 3.
I tried this SQL inside stored procedure:
For
select tbl1_id from table1
where tbl1_sm_id = 2
into :v_tbl1_id
do begin
insert into table1 (tbl1_sm_id, tbl1_name)
select 3, tbl1_name returning tbl1_id into :v_tbl1_id;
insert into table2 (tbl1_id, tbl2_name)
select :v_tbl1_id, tbl2_name
from table2 where tbl1_id = :v_tbl1_id;
end
Is this correct? Is there another way to copy the two tables?
Related
I have a situation with two tables where one has a foreign key pointing to the other table (simplified) schema:
CREATE TABLE table1 (
name VARCHAR(64) NOT NULL,
PRIMARY KEY(name)
);
CREATE TABLE table2 (
id SERIAL PRIMARY KEY,
table1_name VARCHAR(64) NOT NULL REFERENCES table1(name)
);
Now I regret using the name column as primary key in table1 - and would like to add integer serial key instead. Since I already have data in the database I guess I need to do this carefully. My current plan is as follows:
Drop the foreign key constraint: table2(name) with ALTER TABLE table2 DROP CONSTRAINT table2_table1_name_fkey;
Drop the primary key constraint on table1(name) with ALTER TABLE table1 DROP CONSTRAINT name_pkey;.
Add a unique constraint on table1(name) with ALTER TABLE table1 ADD UNIQUE(name);
Add a automatic primary key to table1 with ALTER TABLE table1 ADD COLUMN ID SERIAL PRIMARY KEY;.
Add a new column table1_id to table2 with ALTER TABLE table2 ADD COLUMN table1_id INT;
Update all rows in table2 - so that the new column (which will be promoted to a foreign key) gets the correct value - as inferred by the previous (still present) foreign key table1_name.
I have completed steps up to an including step 5, but the UPDATE (with JOIN?) required to complete 6 is beyond my SQL paygrade. My current (google based ...) attempt looks like:
UPDATE
table2
SET
table2.table1_id = t1.id
FROM
table1 t1
LEFT JOIN table2 t2
ON t2.table1_name = t1.name;
You do not need JOIN in UPDATE.
UPDATE
table2 t2
SET
table1_id = t1.id
FROM
table1 t1
WHERE
t2.table1_name = t1.name;
I have two tables with same structure. I have to find the mismatch columns in both the tables based on id and year combination. Below is the table structure:
id and year is primary key in both the tables.
============================================================
Create table and insert script for table1:
create table table1 (id int, year int, name varchar(50), stat varchar(50), PRIMARY KEY (id,year));
insert into table1 values (1,2021,'Aman','L');
insert into table1 values (2,2021,'Ankit','H');
insert into table1 values (3,2021,'Rahul','G');
insert into table1 values (4,2021,'Gagan','L');
============================================================
Create table and insert script for table2:
create table table2 (id int, year int, name varchar(50), stat varchar(50), PRIMARY KEY (id,year));
insert into table2 values (1,2020,'Aman','H');
insert into table2 values (2,2020,'Anuj','M');
insert into table2 values (3,2020,'Rahul','G')
insert into table2 values (4,2020,'Abhi','L')
============================================================
Expected Output:
for example, id = 1 and year = 2021 from 1st table when compared with id = 1 and year = 2020 (table1 year -1) from table2 should return that stat is different.
id = 2 and year = 2021 from table1 when compared with id = 2 and year = 2020 from table2 should return that name and stat is different.
I need to compare the year-1 from table2 with year column of table1.
Can anyone help me with sql or DB2 query or procedure, how can I do that.
Sounds like you need a simple join
select *
from table1 t1
join table2 t2
on t1.id = t2.id
and t1.year = t2.year + 1
where t1.stat <> t2.stat
or t1.name <> t2.name --if you want this?
I have a table with records which can reference another row in the same table so there is a parent-child relationship between rows in the same table.
What I am trying to achieve is to create the same data for another user so that they can see and manage their own version of this structure through the web ui where these rows are displayed as a tree.
Problem is when I bulk insert this data by only changing user_id, I lose the relation between rows because the parent_id values will be invalid for these new records and they should be updated as well with the newly generated ids.
Here is what I tried: (did not work)
Iterate over main_table
copy-paste the static values after each
do another insert on a temp table for holding old and new ids
update old parent_ids with new ids after loop ends
My attempt at doing such thing(last step is not included here)
create or replace function test_x()
returns void as
$BODY$
declare
r RECORD;
userId int8;
rowPK int8;
begin
userId := (select 1)
create table if not exists id_map (old_id int8, new_id int8);
create table if not exists temp_table as select * from main_table;
for r in select * from temp_table
loop
rowPK := insert into main_table(id, user_id, code, description, parent_id)
values(nextval('hibernate_sequence'), userId, r.code, r.description, r.parent_id) returning id;
insert into id_map (old_id, new_id) values (r.id, rowPK);
end loop;
end
$BODY$
language plpgsql;
My PostgreSQL version is 9.6.14.
DDL below for testing.
create table main_table(
id bigserial not null,
user_id int8 not null,
code varchar(3) not null,
description varchar(100) not null,
parent_id int8 null,
constraint mycompkey unique (user_id, code, parent_id),
constraint mypk primary key (id),
constraint myfk foreign key (parent_id) references main_table(id)
);
insert into main_table (id, user_id, code, description, parent_id)
values(0, 0, '01', 'Root row', null);
insert into main_table (id, user_id, code, description, parent_id)
values(1, 0, '001', 'Child row 1', 0);
insert into main_table (id, user_id, code, description, parent_id)
values(2, 0, '002', 'Child row 2', 0);
insert into main_table (id, user_id, code, description, parent_id)
values(3, 0, '002', 'Grand child row 1', 2);
How to write a procedure to accomplish this?
Thanks in advance.
It appears your task is coping all data for a given user to another while maintaining the hierarchical relationship within the new rows. The following accomplishes that.
It begins creating a new copy of the existing rows with the new user_id, including the old row parent_id. That will be user in the next (update) step.
The CTE logically begins with the new rows which have parent_id and joins to the old parent row. From here it joins to the old parent row to the new parent row using the code and description. At that point we have the new id along with the new parent is. At that point just update with those values. Actually for the update the CTE need only select those two columns, but I've left the intermediate columns so you trace through if you wish.
create or replace function copy_user_data_to_user(
source_user_id bigint
, target_user_id bigint
)
returns void
language plpgsql
as $$
begin
insert into main_table ( user_id,code, description, parent_id )
select target_user_id, code, description, parent_id
from main_table
where user_id = source_user_id ;
with n_list as
(select mt.id, mt.code, mt.description, mt.parent_id
, mtp.id p_id,mtp.code p_code,mtp.description p_des
, mtc.id c_id, mtc.code c_code, mtc.description c_description
from main_table mt
join main_table mtp on mtp.id = mt.parent_id
join main_table mtc on ( mtc.user_id = target_user_id
and mtc.code = mtp.code
and mtc.description = mtp.description
)
where mt.parent_id is not null
and mt.user_id = target_user_id
)
update main_table mt
set parent_id = n_list.c_id
from n_list
where mt.id = n_list.id;
return;
end ;
$$;
-- test
select * from copy_user_data_to_user(0,1);
select * from main_table;
CREATE TABLE 'table name you want to create' SELECT * FROM myset
but new table and myset column name should be equal and you can also
use inplace of * to column name but column name exist in new table
othwerwise getting errors
I'm trying to use the performance of COPY FROM command in PostgreSQL to get all data of 1 table of a CSV file (CSV -> table1) and I need to insert other data, but, in a new table. I will need of a primary key of first table to put as a foreign key in second table.
Example:
I need to insert 1,000,000 of names in table1 and 500,000 of names in table2, but, all names in table2 reference to 1 tuple in table1.
CREATE TABLE table1 (
table1Id bigserial NOT NULL,
Name varchar(100) NULL,
CONSTRAINT table1Id PRIMARY KEY (table1Id)
);
CREATE TABLE table2 (
table2Id bigserial NOT NULL,
Other_name varchar(100) NOT NULL
table1_table1Id int8 NOT NULL,
CONSTRAINT table2_pk PRIMARY KEY (table2Id)
);
Command COPY does not allow table manipulations while copying data (such as look up to other table for fetching proper foreign keys to insert). To insert into table2 ids for corresponding rows from table1 you need to drop NOT NULL constraint for that field, COPY data and then UPDATE that fields separately.
Assuming table1 and table2 tables can be joined by table1.Name = table2.Other_name, the code is:
Before COPY:
ALTER TABLE table2 ALTER COLUMN table1_table1Id DROP NOT NULL;
After COPY:
UPDATE table2 SET table2.table1_table1Id = table1.table1Id
FROM table1
WHERE table1.Name = table2.Other_name;
ALTER TABLE table2 ALTER COLUMN table1_table1Id SET NOT NULL;
I am trying to consult a database using pgAdmin3 and I need to join to tables. I am using the following code:
SELECT table1.species, table1.trait, table1.value, table1.units, table2.id, table2.family, table2.latitude, table2.longitude, table2.species as speciescheck
FROM table1 INNER JOIN table2
ON table1.species = table2.species
But I keep running this error:
an out of memory error
So I've tried to insert my result in a new table, as follow:
CREATE TABLE new_table AS
SELECT table1.species, table1.trait, table1.value, table1.units, table2.id, table2.family, table2.latitude, table2.longitude, table2.species as speciescheck
FROM table1 INNER JOIN table2
ON table1.species = table2.species
And still got an error:
ERROR: could not extend file "base/17675/43101.15": No space left on device
SQL state: 53100
Hint: Check free disk space.
I am very very new at this (is the first time I have to deal with PostgreSQL) and I guess I can do something to optimize this query and avoid this type of error. I have no privileges in the database. Can anyone help??
Thanks in advance!
Updated:
Table 1 description
-- Table: table1
-- DROP TABLE table1;
CREATE TABLE table1
(
species character varying(100),
trait character varying(50),
value double precision,
units character varying(50)
)
WITH (
OIDS=FALSE
);
ALTER TABLE table1
OWNER TO postgres;
GRANT ALL ON TABLE table1 TO postgres;
GRANT SELECT ON TABLE table1 TO banco;
-- Index: speciestable1_idx
-- DROP INDEX speciestable1_idx;
CREATE INDEX speciestable1_idx
ON table1
USING btree
(species COLLATE pg_catalog."default");
-- Index: traittype_idx
-- DROP INDEX traittype_idx;
CREATE INDEX traittype_idx
ON table1
USING btree
(trait COLLATE pg_catalog."default");
and table2 as:
-- Table: table2
-- DROP TABLE table2;
CREATE TABLE table2
(
id integer NOT NULL,
family character varying(40),
species character varying(100),
plotarea real,
latitude double precision,
longitude double precision,
source integer,
latlon geometry,
CONSTRAINT table2_pkey PRIMARY KEY (id)
)
WITH (
OIDS=FALSE
);
ALTER TABLE table2
OWNER TO postgres;
GRANT ALL ON TABLE table2 TO postgres;
GRANT SELECT ON TABLE table2 TO banco;
-- Index: latlon_gist
-- DROP INDEX latlon_gist;
CREATE INDEX latlon_gist
ON table2
USING gist
(latlon);
-- Index: species_idx
-- DROP INDEX species_idx;
CREATE INDEX species_idx
ON table2
USING btree
(species COLLATE pg_catalog."default");
You're performing a join between two tables on the column species.
Not sure what's in your data, but if species is a column with significantly fewer values than the number of records (e.g. if species is "elephant", "giraffe" and you're analyzing all animals in Africa), this join will match every elephant with every elephant.
When joining two tables most of the time you try to use a unique or close to unique attribute, like id (not sure what id means in your case, but could be it).