Postgres unique date column - postgresql

I wanted to create table with unique date column. Is it possible?
I have following table:
CREATE TABLE senders (
id bigint NOT NULL,
number bigint NOT NULL,
inserted_at date NOT NULL
);
I want to be sure I will have unique values per date. For example I can insert (1, 1, '2017-01-01'),(1, 1, '2017-01-02') but I can't add then (1, 1, '2017-01-01') one more time. I tried using UNIQUE constraints creating table or unique indexes but always I have SQL unique exception.
CREATE UNIQUE INDEX senders_unique ON senders (id, number, inserted_at);
CREATE TABLE senders (
id bigint NOT NULL,
number bigint NOT NULL,
inserted_at date NOT NULL,
UNIQUE(id, number, inserted_at)
);
Is it possible. Thanks for all answers.

Related

PostgreSQL: some troubles to insert from select with on conflict

I have some Postgres tables:
CREATE TABLE source_redshift.staticprompts (
id INT,
projectid BIGINT,
scriptid INT,
promptnum INT,
prompttype VARCHAR(20),
inputs VARCHAR(2000),
attributes VARCHAR(2000),
text VARCHAR(2000),
corpuscode VARCHAR(2000),
comment VARCHAR(2000),
created TIMESTAMP,
modified TIMESTAMP
);
and
CREATE TABLE target_redshift.user_input_conf (
collect_project_id BIGINT NOT NULL UNIQUE,
prompt_type VARCHAR(20),
prompt_input_desc VARCHAR(300),
prompt_input_name VARCHAR(100),
no_of_prompt_count BIGINT,
prompt_input_value VARCHAR(100) UNIQUE,
prompt_input_value_id BIGSERIAL PRIMARY KEY,
script_id BIGINT,
corpuscode VARCHAR(20),
min_recordings VARCHAR(2000),
max_recordings VARCHAR(2000),
recordings_count VARCHAR(2000),
lease_duration VARCHAR(2000),
date_created TIMESTAMP WITHOUT TIME ZONE NOT NULL DEFAULT NOW(),
date_updated TIMESTAMP WITHOUT TIME ZONE,
CONSTRAINT must_be_different UNIQUE (prompt_input_value,collect_project_id)
);
I need copy data from staticprompts to user_input_conf with this rules:
Primary Key : prompt_input_value_id
Unique Values : collect_project_id, prompt_input_value
Data Load Logic :
Insert only when new prompt input value is found for given collect project from source. Inputs column stores the values in JSON format in staticprompts table.
Insert :
Generate unique sequence number for each of the new prompt input value for a collect project id from source and store in prompt_input_value_id.
Update :
If prompt value already exists for a collect project and if there are any value changes on prompt_input_desc or prompt input name or prompt input value then update only those columns.
prompt_input_value_id - Generate unique sequence number for the combination of each prompt_input_value and collect_project_id
prompt_input_value - Inputs.value is stored in the inputs column as JSON text. Create a unique record for each inputs.value. Look at the example below this table.
I try to use this query:
INSERT INTO target_redshift.user_input_conf AS t (
collect_project_id,
prompt_type,
prompt_input_desc,
prompt_input_name,
prompt_input_value,
script_id,
corpuscode)
SELECT
s.projectid,
s.prompttype,
s.inputs::jsonb#>>'{inputs,0,desc}' AS desc,
s.inputs::jsonb#>>'{inputs,0,name}' AS name,
s.inputs::jsonb#>>'{inputs,0,values}' AS values,
s.scriptid,
s.corpuscode
FROM source_redshift.staticprompts AS s
ON CONFLICT (collect_project_id, prompt_input_value)
DO UPDATE SET
(prompt_input_desc, prompt_input_name, prompt_input_value, date_updated) =
(EXCLUDED.prompt_input_desc, EXCLUDED.prompt_input_name, EXCLUDED.prompt_input_value, NOW())
WHERE t.prompt_input_desc != EXCLUDED.prompt_input_desc
OR t.prompt_input_name != EXCLUDED.prompt_input_name
OR t.prompt_input_value != EXCLUDED.prompt_input_value;
""")
But I get an error:
psycopg2.errors.UniqueViolation: duplicate key value violates unique constraint "user_input_conf_collect_project_id_key"
DETAIL: Key (collect_project_id)=(1) already exists.
I think there is a misunderstanding. A unique constraint over two columns does not mean that each of the columns is unique, but that the combination of the two columns is unique.
So your must_be_different is different (and weaker) than the unique constraints on prompt_input_value and collect_project_id. For example, if you have the three rows
collect_project_id | prompt_input_value
--------------------+--------------------
1 | a
1 | b
2 | b
they will create a conflict with both single-column unique constraints, but nor with must_be_different.
I guess that the underlying problem is that you want to use INSERT ... ON CONFLICT with multiple unique constraints. That cannot be done; see this question for a discussion and potential solutions.

PostgreSQL trigger for inserting an entry in table2 AFTER a row is inserted in table1 (using the values from newly inserted row in table1)

I have displayed my database schema below.
CREATE TABLE table_group
(
group_id serial NOT NULL,
group_creator_id integer NOT NULL,
group_name character varying(20) NOT NULL,
active_status boolean NOT NULL,
PRIMARY KEY (group_id),
)
CREATE TABLE table_group_members
(
group_member_id serial NOT NULL,
group_id integer REFERENCES table_group (group_id) NOT NULL,
member_user_id integer REFERENCES table_group (group_creator_id) NOT NULL,
PRIMARY KEY (group_member_id)
)
I want to INSERT a new row in the table table_group_members as soon a new row is inserted in table table_group.
I want to pass the group_id and group_creator_id of the newly inserted row in the table table_group as parameters to INSERT query for the table table_group_members
How should I do it using the PostgreSQL TRIGGER?

Many-to-one relationship using two unique keys

I have two tables which look like thiS:
uploads
________
id (primary key)
user_id
file_checksum
upload_information
---------
upload_info_id (primary key)
file_checksum
metadata1
metdata2
The "many to one" relationship I am trying to enforce is this:
Many uploads can have the same file checksum
However, the file checksum can only ever point to one upload_information record, thus making the unique constraint between file_checksum and upload_info_id mandatory in the upload_information table.
I am wondering how to alter these tables in Postgres in order to achieve this relationship.
CREATE TABLE uploads (
id SERIAL NOT NULL PRIMARY KEY,
created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
user_id VARCHAR NOT NULL,
file_checksum VARCHAR NOT NULL,
);
CREATE TABLE upload_information (
upload_info_id SERIAL NOT NULL PRIMARY KEY,
created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
file_checksum VARCHAR NOT NULL,
file_name VARCHAR NOT NULL,
source_file_url VARCHAR NOT NULL,
);
Add a unique index on file_checksum.
create unique index unique_checksum on upload_information(file_checksum)

Alter table to add 'partition by range' in postgres

I want to alter table with adding partition by range with archivedate.
CREATE TABLE transactions(
id UUID not null ,
txn_id UUID NOT NULL,
orderId UUID NOT NULL,
inserttstmp timestamp not NULL
archivedate timestamp NULL
)
usually, whenever i'm creating new table with partition with below script. But now want to do same for existing tables.
CREATE TABLE attachment(
id UUID not null,
txn_id UUID NOT NULL,
attachment_id UUID NOT NULL,
inserttstmp timestamp not NULL
archivedate timestamp NULL
)PARTITION BY RANGE (archivedate);
CREATE TABLE ins_txn_attachment_live PARTITION OF ins_txn_attachment DEFAULT;
ALTER TABLE ins_txn_attachment_live ADD CHECK (archivedate is null);
ALTER TABLE ins_txn_attachment_live ADD CONSTRAINT PK_INS_TXN_ATTACHMENT_EVENT_Live unique (id);
CREATE UNIQUE NONCLUSTERED INDEX PK_Ins_TXN_Attachment_ID_ArchiveData ON ins_txn_attachment (id,archivedate);
Thanks,
Jagadeesh

Postgres before insert trigger using sequence from another table

Using Postgres, what I would like to achieve is to be able to have many different instrument types, with corresponding [TYPE].instrument tables, which all have a unique ID in the table, but also reference a unique ID in the instrument.master table. I have the following:
create schema instrument
CREATE TABLE instrument.type (
id smallserial NOT NULL,
name text not null,
code text not null,
CONSTRAINT pk_instrument_type PRIMARY KEY (id)
);
ALTER TABLE instrument.type ADD CONSTRAINT unq_instrument_type_code UNIQUE(code);
ALTER TABLE instrument.type ADD CONSTRAINT unq_instrument_type_name UNIQUE(name);
insert into instrument.type (name, code) values ('futures', 'f');
CREATE TABLE instrument.master (
id serial NOT NULL,
type smallint not null references instrument.type (id),
timestamp timestamp with time zone not null,
CONSTRAINT pk_instrument_master PRIMARY KEY (id)
);
CREATE TABLE futures.definition (
id smallserial NOT NULL,
code text not null,
CONSTRAINT pk_futures_definition PRIMARY KEY (id)
);
ALTER TABLE futures.definition ADD CONSTRAINT unq_futures_definition_code UNIQUE(code);
insert into futures.definition (code) values ('ED');
CREATE TABLE futures.instrument (
id smallserial NOT NULL,
master serial not null references instrument.master (id),
definition smallint not null references futures.definition (id),
month smallint not null,
year smallint not null,
CONSTRAINT pk_futures_instrument PRIMARY KEY (id),
check (month >= 1),
check (month <= 12),
check (year >= 1900)
);
ALTER TABLE futures.instrument ADD CONSTRAINT unq_futures_instrument UNIQUE(definition, month, year);
CREATE OR REPLACE FUNCTION trigger_master_futures()
RETURNS trigger AS
$BODY$
BEGIN
insert into instrument.master (type, timestamp)
select id, current_timestamp from instrument.type where code = 'f';
NEW.master := currval('instrument.master_id_seq');
RETURN NEW;
END;
$BODY$
LANGUAGE 'plpgsql' VOLATILE;
create trigger trg_futures_instrument before insert on futures.instrument
for each row
execute procedure trigger_master_futures();
I then test with:
insert into futures.instrument (definition, month, year)
select id, 3, 2015 from futures.definition where code = 'ED';
Everything works almost as I would like it to. The only issue is that somehow, instrument.master.id ends up being one more than futures.instrument.master. I am not sure what I need to do to achieve the behavior I want, which is that whenever an entry is inserted into futures.instrument, an entry should be inserted into instrument.master, and the id entry of the latter should be inserted into the master entry of the former. I actually think it should have failed since the foreign key relationship is violated somehow.
As it turns out, everything was correct. The issue was that in futures.instrument, the type of the master column is serial, and it should have been int.