Related
I have a column with entries like:
column:
156781
234762
780417
and would like to have the following:
column:
0000156781
0000234762
0000780417
For this I use the following query:
Select isnull(replicate('0', 10 - len(column)),'') + rtrim(column) as a from table)
However, I don't know how to replace the values in the whole column.
I already tried with:
UPDATE table
SET column= (
Select isnull(replicate('0', 10 - len(column)),'') + rtrim(column) as columnfrom table)
But I get the following error.
Subquery returned more than 1 value. This is not permitted when the subquery follows =, !=, <, <= , >, >= or when the subquery is used as an expression.
The answer to your question is going to depend on the data type of your column. If it is a text column for example VARCHAR then you can modify the value in the table. If it is a number type such as INT it is the value and not the characters which is stored.
We can also express this by saying that "0" + "1" = "01" whilst 0 + 1 = 1.
In either case we can format the value in a query.
create table numberz(
val1 int,
val2 varchar(10));
insert into numberz values
(156781,'156781'),
(234762,'234762'),
(780417,'780417');
/* required format
0000156781
0000234762
0000780417
*/
select * from numberz;
GO
val1 | val2
-----: | :-----
156781 | 156781
234762 | 234762
780417 | 780417
UPDATE numberz
SET val1 = isnull(
replicate('0',
10 - len(val1)),'')
+ rtrim(val1),
val2 = isnull(
replicate('0',
10 - len(val2)),'')
+ rtrim(val2);
GO
3 rows affected
select * from numberz;
GO
val1 | val2
-----: | :---------
156781 | 0000156781
234762 | 0000234762
780417 | 0000780417
select isnull(
replicate('0',
10 - len(val1)),'')
+ rtrim(val1)
from numberz
GO
| (No column name) |
| :--------------- |
| 0000156781 |
| 0000234762 |
| 0000780417 |
db<>fiddle here
Usually, when we need to show values in specificity format these processes are performed using the CASE command or with other functions on the selection field list, mean without updating. In such cases, we can change our format to any format and anytime with changing functions. As dynamic fields.
For example:
select id, lpad(id::text, 6, '0') as format_id from test.test_table1
order by id
Result:
id format_id
-------------
1 000001
2 000002
3 000003
4 000004
5 000005
Maybe you really need an UPDATE, so I wrote a sample query for an UPDATE command too.
update test.test_table1
set
id = lpad(id::text, 6, '0');
I have 2 string columns (thousands of rows) with ordered numbers in each string (there can be zero to ten numbers in each string). Example:
+------------------+------------+
| ColString1 | ColString2 |
+------------------+------------+
| 1;3;5;12; | 4;6' |
+------------------+------------+
| 1;5;10 | 2;26; |
+------------------+------------+
| 4;7; | 3; |
+------------------+------------+
The end result is to combine these 2 columns, sort the numbers in
ascending order and then put each number into individual columns (smallest, 2nd smallest etc).
e.g. Colstring1 is 1;3;5;12; and ColString2 is 4;6; needs to return 1;3;4;5;6;12; which I then use xml to allocated into columns.
Everthing works fine using xml apart from the step to order the numbers (i.e I'm getting 1;3;5;12;4;6; when I combine the strings i.e. not in ascending order).
I've tried put them into a JSON array first to order, thinking I could do a top[1] etc but that did not work.
Any help on how to combine the 2 columns and order them before inserting into columns:
Steps so far:
Example data:
DECLARE #tbl TABLE (ID INT IDENTITY PRIMARY KEY, ColString1 VARCHAR(50), ColString2 VARCHAR(50));
INSERT INTO #tbl (ColString1, ColString2)
VALUES
('1;3;5;12;', '4;6;'),
('1;5;10;', '2;26;'),
('14;', '3;8;');
XML Approach (Combines strings and puts into columns but not in the correct order):
;WITH Split_Numbers (xmlname)
AS
(
SELECT
CONVERT(XML,'<Names><name>'
+ REPLACE ( LEFT(ColString1+ColString2,LEN(ColString1+ColString2) - 1),';', '</name><name>') + '</name></Names>') AS xmlname
FROM #tbl
)
SELECT
xmlname.value('/Names[1]/name[1]','int') AS Number1,
xmlname.value('/Names[1]/name[2]','int') AS Number2,
xmlname.value('/Names[1]/name[3]','int') AS Number3,
xmlname.value('/Names[1]/name[4]','int') AS Number4,
xmlname.value('/Names[1]/name[5]','int') AS Number5
--etc for additional columns
FROM Split_Numbers
Current Output: numbers not in correct order,
+---------+---------+---------+---------+---------+
| Number1 | Number2 | Number3 | Number4 | Number5 |
+---------+---------+---------+---------+---------+
| 1 | 3 | 5 | 12 | 4 |
| 1 | 5 | 10 | 2 | 26 |
| 14 | 3 | 8 | NULL | NULL |
+---------+---------+---------+---------+---------+
Desired Output: numbers in ascending order.
+---------+---------+---------+---------+---------+
| Number1 | Number2 | Number3 | Number4 | Number5 |
+---------+---------+---------+---------+---------+
| 1 | 3 | 4 | 5 | 6 |
| 1 | 2 | 5 | 10 | 26 |
| 3 | 8 | 14 | NULL | NULL |
+---------+---------+---------+---------+---------+
JSON Approach: combines the columns into a JSON array but I still can't order correctly when in JSON format.
REPLACE ( CONCAT('[', LEFT(ColString1+ColString2,LEN(ColString1+ColString2) - 1), ']') ,';',',')
Any help will be greatly appreciated whether there is a way to order the xml or JSON string prior to entry. Happy to consider an alternative way if there is an easier solution.
You can use string_agg() and string_split():
select t.*, newstring
from t cross apply
(select string_agg(value, ',') order by (value) as newstring
from (select s1.value
from unnest(colstring1, ',') s1
union all
select s2.value
from unnest(colstring2, ',') s2
) s
) s;
That said, you should probably put your effort into fixing the data model. Storing numbers in strings is bad. Storing multiple values in a string is bad, bad. If the numbers are foreign references to other tables, that is bad, bad, bad, bad, bad.
While waiting for a DDL and sample data population, etc., here is a conceptual example for you. It is using XQuery and its FLWOR expression.
CTE does most of the heavy lifting:
Concatenates both columns values into one string. CONCAT() function protects against NULL values.
Converts it into XML data type.
Sorts XML elements by converting their values to int data type in the FLWOR expression.
Filters out XML elements with no legit values.
The rest is trivial.
SQL
-- DDL and sample data population, start
DECLARE #tbl TABLE (ID INT IDENTITY PRIMARY KEY, col1 VARCHAR(100), col2 VARCHAR(100));
INSERT INTO #tbl (col1, col2)
VALUES
('1;3;5;12;', '4;6;'),
('1;5;10;', '2;26;');
-- DDL and sample data population, end
DECLARE #separator CHAR(1) = ';';
;WITH rs AS
(
SELECT *
, CAST('<root><r><![CDATA[' +
REPLACE(CONCAT(col1, col2), #separator, ']]></r><r><![CDATA[') +
']]></r></root>' AS XML).query('<root>
{
for $x in /root/r[text()]
order by xs:int($x)
return $x
}
</root>') AS sortedXML
FROM #tbl
)
SELECT ID
, c.value('(r[1]/text())[1]','INT') AS Number1
, c.value('(r[2]/text())[1]','INT') AS Number2
, c.value('(r[3]/text())[1]','INT') AS Number3
-- continue with the rest of the columns
FROM rs CROSS APPLY sortedXML.nodes('/root') AS t(c);
Output
+----+---------+---------+---------+
| ID | Number1 | Number2 | Number3 |
+----+---------+---------+---------+
| 1 | 1 | 3 | 4 |
| 2 | 1 | 2 | 5 |
+----+---------+---------+---------+
I have a bunch of data that contains a phone number and a birthday as well as other data.
{1997-06-28,07742367858}
{07791100873,1996-07-14}
{30/01/1997,07974335488}
{1997-04-04,07701003703}
{1996-03-11,07480227283}
{1998-06-20,07713817233}
{1996-09-13,07435148920}
{"21 03 2000",07548542539,1st}
{1996-03-09,07539248008}
{07484642432,1996-03-01}
I am trying to extract the phone number from this, however unsure on how to get this out when the data is not always in the same order.
I would expect to one column that return a phone number, the next which returned a birthday then another which return any arbitrary value in the 3rd column slot.
You can try to sort parts of each string by the number of digits they contain. This can be done with the expression:
select length(regexp_replace('1997-06-28', '\D', '', 'g'))
length
--------
8
(1 row)
The query removes curly brackets from strings, splits them by comma, sorts elements by the number of digits and aggregates back to arrays:
with my_data(str) as (
values
('{1997-06-28,07742367858}'),
('{07791100873,1996-07-14}'),
('{30/01/1997,07974335488}'),
('{1997-04-04,07701003703}'),
('{1996-03-11,07480227283}'),
('{1998-06-20,07713817233}'),
('{1996-09-13,07435148920}'),
('{"21 03 2000",07548542539,1st}'),
('{1996-03-09,07539248008}'),
('{07484642432,1996-03-01}')
)
select id, array_agg(elem order by length(regexp_replace(elem, '\D', '', 'g')) desc)
from (
select id, trim(unnest(string_to_array(str, ',')), '"') as elem
from (
select trim(str, '{}') as str, row_number() over () as id
from my_data
) s
) s
group by id
Result:
id | array_agg
----+--------------------------------
1 | {07742367858,1997-06-28}
2 | {07791100873,1996-07-14}
3 | {07974335488,30/01/1997}
4 | {07701003703,1997-04-04}
5 | {07480227283,1996-03-11}
6 | {07713817233,1998-06-20}
7 | {07435148920,1996-09-13}
8 | {07548542539,"21 03 2000",1st}
9 | {07539248008,1996-03-09}
10 | {07484642432,1996-03-01}
(10 rows)
See also this answer Looking for solution to swap position of date format DMY to YMD if you want to normalize dates. You should modify the function:
create or replace function iso_date(text)
returns date language sql immutable as $$
select case
when $1 like '__/__/____' then to_date($1, 'DD/MM/YYYY')
when $1 like '____/__/__' then to_date($1, 'YYYY/MM/DD')
when $1 like '____-__-__' then to_date($1, 'YYYY-MM-DD')
when trim($1, '"') like '__ __ ____' then to_date(trim($1, '"'), 'DD MM YYYY')
end
$$;
and use it:
select id, a[1] as phone, iso_date(a[2]) as birthday, a[3] as comment
from (
select id, array_agg(elem order by length(regexp_replace(elem, '\D', '', 'g')) desc) as a
from (
select id, trim(unnest(string_to_array(str, ',')), '"') as elem
from (
select trim(str, '{}') as str, row_number() over () as id
from my_data
) s
) s
group by id
) s
id | phone | birthday | comment
----+-------------+------------+---------
1 | 07742367858 | 1997-06-28 |
2 | 07791100873 | 1996-07-14 |
3 | 07974335488 | 1997-01-30 |
4 | 07701003703 | 1997-04-04 |
5 | 07480227283 | 1996-03-11 |
6 | 07713817233 | 1998-06-20 |
7 | 07435148920 | 1996-09-13 |
8 | 07548542539 | 2000-03-21 | 1st
9 | 07539248008 | 1996-03-09 |
10 | 07484642432 | 1996-03-01 |
(10 rows)
I'm trying to merge tables where rows correspond to a many:1 relationship with "real" things.
I'm writing a blackjack simulator that stores game history in a database with a new set of tables generated each run. The tables are really more like templates, since each game gets its own set of the 3 mutable tables (players, hands, and matches). Here's the layout, where suff is a user-specified suffix to use for the current run:
- cards
- id INTEGER PRIMARY KEY
- cardValue INTEGER NOT NULL
- suit INTEGER NOT NULL
- players_suff
- whichPlayer INTEGER PRIMARY KEY
- aiType TEXT NOT NULL
- hands_suff
- id BIGSERIAL PRIMARY KEY
- whichPlayer INTEGER REFERENCES players_suff(whichPlayer) *
- whichHand BIGINT NOT NULL
- thisCard INTEGER REFERENCES cards(id)
- matches_suff
- id BIGSERIAL PRIMARY KEY
- whichGame INTEGER NOT NULL
- dealersHand BIGINT NOT NULL
- whichPlayer INTEGER REFERENCES players_suff(whichPlayer)
- thisPlayersHand BIGINT NOT NULL **
- playerResult INTEGER NOT NULL --AKA who won
Only one cards table is created because its values are constant.
So after running the simulator twice you might have:
hands_firstrun
players_firstrun
matches_firstrun
hands_secondrun
players_secondrun
matches_secondrun
I want to be able to combine these tables if you used the same AI parameters for both of those runs (i.e. players_firstrun and players_secondrun are exactly the same). The problem is that the way I'm inserting hands makes this really messy: whichHand can't be a BIGSERIAL because the relationship of hands_suff rows to "actual hands" is many:1. matches_suff is handled the same way because a blackjack "game" actually consists of a set of games: the set of pairs of each player vs. the dealer. So for 3 players, you actually have 3 rows for each round.
Currently I select the largest whichHand in the table, add 1 to it, then insert all of the rows for one hand. I'm worried this "query-and-insert" will be really slow if I'm merging 2 tables that might both be arbitrarily huge.
When I'm merging tables, I feel like I should be able to (entirely in SQL) query the largest values in whichHand and whichGame once then use them combine the tables, incrementing them for each unique whichHand and whichGame in the table being merged.
(I saw this question, but it doesn't handle using a generated ID in 2 different places). I'm using Postgres and it's OK if the answer is specific to it.
* sadly postgres doesn't allow parameterized table names so this had to be done by manual string substitution. Not the end of the world since the program isn't web-facing and no one except me is likely to ever bother with it, but the SQL injection vulnerability does not make me happy.
** matches_suff(whichPlayersHand) was originally going to reference hands_suff(whichHand) but foreign keys must reference unique values. whichHand isn't unique because a hand is made up of multiple rows, with each row "holding" one card. To query for a hand you select all of those rows with the same value in whichHand. I couldn't think of a more elegant way to do this without resorting to arrays.
EDIT:
This is what I have now:
thomas=# \dt
List of relations
Schema | Name | Type | Owner
--------+----------------+-------+--------
public | cards | table | thomas
public | hands_first | table | thomas
public | hands_second | table | thomas
public | matches_first | table | thomas
public | matches_second | table | thomas
public | players_first | table | thomas
public | players_second | table | thomas
(7 rows)
thomas=# SELECT * FROM hands_first
thomas-# \g
id | whichplayer | whichhand | thiscard
----+-------------+-----------+----------
1 | 0 | 0 | 6
2 | 0 | 0 | 63
3 | 0 | 0 | 41
4 | 1 | 1 | 76
5 | 1 | 1 | 23
6 | 0 | 2 | 51
7 | 0 | 2 | 29
8 | 0 | 2 | 2
9 | 0 | 2 | 92
10 | 0 | 2 | 6
11 | 1 | 3 | 101
12 | 1 | 3 | 8
(12 rows)
thomas=# SELECT * FROM hands_second
thomas-# \g
id | whichplayer | whichhand | thiscard
----+-------------+-----------+----------
1 | 0 | 0 | 78
2 | 0 | 0 | 38
3 | 1 | 1 | 24
4 | 1 | 1 | 18
5 | 1 | 1 | 95
6 | 1 | 1 | 40
7 | 0 | 2 | 13
8 | 0 | 2 | 84
9 | 0 | 2 | 41
10 | 1 | 3 | 29
11 | 1 | 3 | 34
12 | 1 | 3 | 56
13 | 1 | 3 | 52
thomas=# SELECT * FROM matches_first
thomas-# \g
id | whichgame | dealershand | whichplayer | thisplayershand | playerresult
----+-----------+-------------+-------------+-----------------+--------------
1 | 0 | 0 | 1 | 1 | 1
2 | 1 | 2 | 1 | 3 | 2
(2 rows)
thomas=# SELECT * FROM matches_second
thomas-# \g
id | whichgame | dealershand | whichplayer | thisplayershand | playerresult
----+-----------+-------------+-------------+-----------------+--------------
1 | 0 | 0 | 1 | 1 | 0
2 | 1 | 2 | 1 | 3 | 2
(2 rows)
I'd like to combine them to have:
hands_combined table:
id | whichplayer | whichhand | thiscard
----+-------------+-----------+----------
1 | 0 | 0 | 6 --Seven of Spades
2 | 0 | 0 | 63 --Queen of Spades
3 | 0 | 0 | 41 --Three of Clubs
4 | 1 | 1 | 76
5 | 1 | 1 | 23
6 | 0 | 2 | 51
7 | 0 | 2 | 29
8 | 0 | 2 | 2
9 | 0 | 2 | 92
10 | 0 | 2 | 6
11 | 1 | 3 | 101
12 | 1 | 3 | 8
13 | 0 | 4 | 78
14 | 0 | 4 | 38
15 | 1 | 5 | 24
16 | 1 | 5 | 18
17 | 1 | 5 | 95
18 | 1 | 5 | 40
19 | 0 | 6 | 13
20 | 0 | 6 | 84
21 | 0 | 6 | 41
22 | 1 | 7 | 29
23 | 1 | 7 | 34
24 | 1 | 7 | 56
25 | 1 | 7 | 52
matches_combined table:
id | whichgame | dealershand | whichplayer | thisplayershand | playerresult
----+-----------+-------------+-------------+-----------------+--------------
1 | 0 | 0 | 1 | 1 | 1
2 | 1 | 2 | 1 | 3 | 2
3 | 2 | 4 | 1 | 5 | 0
4 | 3 | 6 | 1 | 7 | 2
Each value of "thiscard" represents a playing card in the range [1..104]--52 playing cards with an extra bit representing if it's face up or face down. I didn't post the actual table for space reasons.
So player 0 (aka the dealer) had a hand of (Seven of Spades, Queen of Spaces, 3 of Clubs) in the first game.
I think you're not using PostgreSQL the way it's intended to be used, plus your table design may not be suitable for what you want to achieve. Whilst it was difficult to understand what you want your solution to achieve, I wrote this, which seems to solve everything you want using a handful of tables only, and functions that return recordsets for simulating your requirement for individual runs. I used Enums and complex types to illustrate some of the features that you may wish to harness from the power of PostgreSQL.
Also, I'm not sure what parameterized table names are (I have never seen anything like it in any RDBMS), but PostgreSQL does allow something perfectly suitable: recordset returning functions.
CREATE TYPE card_value AS ENUM ('1', '2', '3', '4', '5', '6', '7', '8', '9', '10', 'J', 'Q', 'K');
CREATE TYPE card_suit AS ENUM ('Clubs', 'Diamonds', 'Hearts', 'Spades');
CREATE TYPE card AS (value card_value, suit card_suit, face_up bool);
CREATE TABLE runs (
run_id bigserial NOT NULL PRIMARY KEY,
run_date timestamptz NOT NULL DEFAULT CURRENT_TIMESTAMP
);
CREATE TABLE players (
run_id bigint NOT NULL REFERENCES runs,
player_no int NOT NULL, -- 0 can be assumed as always the dealer
ai_type text NOT NULL,
PRIMARY KEY (run_id, player_no)
);
CREATE TABLE matches (
run_id bigint NOT NULL REFERENCES runs,
match_no int NOT NULL,
PRIMARY KEY (run_id, match_no)
);
CREATE TABLE hands (
hand_id bigserial NOT NULL PRIMARY KEY,
run_id bigint NOT NULL REFERENCES runs,
match_no int NOT NULL,
hand_no int NOT NULL,
player_no int NOT NULL,
UNIQUE (run_id, match_no, hand_no),
FOREIGN KEY (run_id, match_no) REFERENCES matches,
FOREIGN KEY (run_id, player_no) REFERENCES players
);
CREATE TABLE deals (
deal_id bigserial NOT NULL PRIMARY KEY,
hand_id bigint NOT NULL REFERENCES hands,
card card NOT NULL
);
CREATE OR REPLACE FUNCTION players(int) RETURNS SETOF players AS $$
SELECT * FROM players WHERE run_id = $1 ORDER BY player_no;
$$ LANGUAGE SQL;
CREATE OR REPLACE FUNCTION matches(int) RETURNS SETOF matches AS $$
SELECT * FROM matches WHERE run_id = $1 ORDER BY match_no;
$$ LANGUAGE SQL;
CREATE OR REPLACE FUNCTION hands(int) RETURNS SETOF hands AS $$
SELECT * FROM hands WHERE run_id = $1 ORDER BY match_no, hand_no;
$$ LANGUAGE SQL;
CREATE OR REPLACE FUNCTION hands(int, int) RETURNS SETOF hands AS $$
SELECT * FROM hands WHERE run_id = $1 AND match_no = $2 ORDER BY hand_no;
$$ LANGUAGE SQL;
CREATE OR REPLACE FUNCTION winner_player (int, int) RETURNS int AS $$
SELECT player_no
FROM hands
WHERE run_id = $1 AND match_no = $2
ORDER BY hand_no DESC
LIMIT 1
$$ LANGUAGE SQL;
CREATE OR REPLACE FUNCTION next_player_no (int) RETURNS int AS $$
SELECT CASE WHEN EXISTS (SELECT 1 FROM runs WHERE run_id = $1) THEN
COALESCE((SELECT MAX(player_no) FROM players WHERE run_id = $1), 0) + 1 END
$$ LANGUAGE SQL;
CREATE OR REPLACE FUNCTION next_match_no (int) RETURNS int AS $$
SELECT CASE WHEN EXISTS (SELECT 1 FROM runs WHERE run_id = $1) THEN
COALESCE((SELECT MAX(match_no) FROM matches WHERE run_id = $1), 0) + 1 END
$$ LANGUAGE SQL;
CREATE OR REPLACE FUNCTION next_hand_no (int) RETURNS int AS $$
SELECT CASE WHEN EXISTS (SELECT 1 FROM runs WHERE run_id = $1) THEN
COALESCE((SELECT MAX(hand_no) + 1 FROM hands WHERE run_id = $1), 0) END
$$ LANGUAGE SQL;
CREATE OR REPLACE FUNCTION card_to_int (card) RETURNS int AS $$
SELECT ((SELECT enumsortorder::int-1 FROM pg_enum WHERE enumtypid = 'card_suit'::regtype AND enumlabel = ($1).suit::name) * 13 +
(SELECT enumsortorder::int-1 FROM pg_enum WHERE enumtypid = 'card_value'::regtype AND enumlabel = ($1).value::name) + 1) *
CASE WHEN ($1).face_up THEN 2 ELSE 1 END
$$ LANGUAGE SQL; -- SELECT card_to_int(('3', 'Spades', false))
CREATE OR REPLACE FUNCTION int_to_card (int) RETURNS card AS $$
SELECT ((SELECT enumlabel::card_value FROM pg_enum WHERE enumtypid = 'card_value'::regtype AND enumsortorder = ((($1-1)%13)+1)::real),
(SELECT enumlabel::card_suit FROM pg_enum WHERE enumtypid = 'card_suit'::regtype AND enumsortorder = (((($1-1)/13)::int%4)+1)::real),
$1 > (13*4))::card
$$ LANGUAGE SQL; -- SELECT i, int_to_card(i) FROM generate_series(1, 13*4*2) i
CREATE OR REPLACE FUNCTION deal_cards(int, int, int, int[]) RETURNS TABLE (player_no int, hand_no int, card card) AS $$
WITH
hand AS (
INSERT INTO hands (run_id, match_no, player_no, hand_no)
VALUES ($1, $2, $3, next_hand_no($1))
RETURNING hand_id, player_no, hand_no),
mydeals AS (
INSERT INTO deals (hand_id, card)
SELECT hand_id, int_to_card(card_id)::card AS card
FROM hand, UNNEST($4) card_id
RETURNING hand_id, deal_id, card
)
SELECT h.player_no, h.hand_no, d.card
FROM hand h, mydeals d
$$ LANGUAGE SQL;
CREATE OR REPLACE FUNCTION deals(int) RETURNS TABLE (deal_id bigint, hand_no int, player_no int, card int) AS $$
SELECT d.deal_id, h.hand_no, h.player_no, card_to_int(d.card)
FROM hands h
JOIN deals d ON (d.hand_id = h.hand_id)
WHERE h.run_id = $1
ORDER BY d.deal_id;
$$ LANGUAGE SQL;
INSERT INTO runs DEFAULT VALUES; -- Add first run
INSERT INTO players VALUES (1, 0, 'Dealer'); -- dealer always zero
INSERT INTO players VALUES (1, next_player_no(1), 'Player 1');
INSERT INTO matches VALUES (1, next_match_no(1)); -- First match
SELECT * FROM deal_cards(1, 1, 0, ARRAY[6, 63, 41]);
SELECT * FROM deal_cards(1, 1, 1, ARRAY[76, 23]);
SELECT * FROM deal_cards(1, 1, 0, ARRAY[51, 29, 2, 92, 6]);
SELECT * FROM deal_cards(1, 1, 1, ARRAY[101, 8]);
INSERT INTO matches VALUES (1, next_match_no(1)); -- Second match
SELECT * FROM deal_cards(1, 2, 0, ARRAY[78, 38]);
SELECT * FROM deal_cards(1, 2, 1, ARRAY[24, 18, 95, 40]);
SELECT * FROM deal_cards(1, 2, 0, ARRAY[13, 84, 41]);
SELECT * FROM deal_cards(1, 2, 1, ARRAY[29, 34, 56, 52]);
SELECT * FROM deals(1); -- This is the output you need (hands_combined table)
-- This view can be used to retrieve the list of all winning hands
CREATE OR REPLACE VIEW winning_hands AS
SELECT DISTINCT ON (run_id, match_no) *
FROM hands
ORDER BY run_id, match_no, hand_no DESC;
SELECT * FROM winning_hands;
Wouldn't using the UNION operator work?
For the hands relation:
SELECT * FROM hands_first
UNION ALL
SELECT * FROM hands_second
For the matches relation:
SELECT * FROM matches_first
UNION ALL
SELECT * FROM matches_second
As a more long term solution I'd consider restructuring the DB because it will quickly become unmanageable with this schema. Why not improve normalization by introducing a games table?
In other words Games have many Matches, matches have many players for each game and players have many hands for each match.
I'd recommend drawing the UML for the entity relationships on paper (http://dawgsquad.googlecode.com/hg/docs/database_images/Database_Model_Diagram(Title).png), then improving the schema so it can be queried using normal SQL operators.
Hope this helps.
EDIT:
In that case you can use a subquery on the union of both tables with the rownumber() PG function to represent the row number:
SELECT
row_number() AS id,
whichplayer,
whichhand,
thiscard
FROM
(
SELECT * FROM hands_first
UNION ALL
SELECT * FROM hands_second
);
The same principle would apply to the matches table. Obviously this doesn't scale well to even a small number of tables, so would prioritize normalizing your schema.
Docs on some PG functions: http://www.postgresql.org/docs/current/interactive/functions-window.html
to build new table with all rows of two tables, do:
CREATE TABLE hands AS
select 1 as hand, id, whichplayer, whichhand, thiscard
from hands_first
union all
select 2 as hand, id, whichplayer, whichhand, thiscard
from hands_second
after that, to insert data of new matche, create sequence with start on current last + 1
CREATE SEQUENCE matche START 3;
before insert read sequence value, and use it in inserts:
SELECT nextval('matche');
Your database structure is not great, and I know for sure it is not scalable approach creating tables on fly. There are performance drawbacks creating physical tables instead of using an existing structure. I suggest you refactor your db structure if can.
You can however use the UNION operator to merge your data.
I have 2 tables: errorlookup and errors.
errorlookup has 2 columns: codes and description.
The codes are of length 2.
errors has 2 columns id and errorcodes.
The errorcodes are of length 40 meaning they code store 20 error codes for each id.
I need to display all the description associated with the id by substring the errorcodes and matching with code in errorlookup table.
Sample data for errorlookup:
codes:description
12:Invalid
22:Inactive
21:active
Sample data for errors:
id:errorcodes
1:1221
2:2112
3:1222
I cant use LIKE as it would result in too many errors. I want the errorcodes column to be broken down into strings of length 2 and then joined with the errorlookup.
How can it be done?
If you really cannot alter the tables structure, here's another approach:
Create an auxilary numbers table:
CREATE TABLE numbers
( i INT NOT NULL
, PRIMARY KEY (i)
) ;
INSERT INTO numbers VALUES
( 1 ) ;
INSERT INTO numbers VALUES
( 2 ) ;
--- ...
INSERT INTO numbers VALUES
( 100 ) ;
Then you could use this:
SELECT err.id
, err.errorcodes
, num.i
, look.codes
, look.descriptionid
FROM
( SELECT i, 2*i-1 AS pos --- odd numbers
FROM numbers
WHERE i <= 20 --- 20 pairs
) num
CROSS JOIN
errors err
JOIN
errorlookup look
ON look.codes = SUBSTR(err.errorcodes, pos, 2)
ORDER BY
err.errorcodes
, num.i ;
Test at: SQL-Fiddle
ID ERRORCODES I CODES DESCRIPTIONID
1 1221 1 12 Invalid
1 1221 2 21 Active
3 1222 1 12 Invalid
3 1222 2 22 Inactive
2 2112 1 21 Active
2 2112 2 12 Invalid
I think the cleanest solution is to "normalize" your errocodes table using a PL/SQL function. That way you can keep the current (broken) table design, but still access its content as if it was properly normlized.
create type error_code_type as object (id integer, code varchar(2))
/
create or replace type error_table as table of error_code_type
/
create or replace function unnest_errors
return error_table pipelined
is
codes_l integer;
i integer;
one_row error_code_type := error_code_type(null, null);
begin
for err_rec in (select id, errorcodes from errors) loop
codes_l := length(err_rec.errorcodes);
i := 1;
while i < codes_l loop
one_row.id := err_rec.id;
one_row.code := substr(err_rec.errorcodes, i, 2);
pipe row (one_row);
i := i + 2;
end loop;
end loop;
end;
/
Now with this function you can do something like this:
select er.id, er.code, el.description
from table(unnest_errors) er
join errorlookup el on el.codes = er.code;
You can also create a view based on the function to make the statements a bit easier to read:
create or replace view normalized_errorcodes
as
select *
from table(unnest_errors);
Then you can simply reference the view in the real statement.
(I tested this on 11.2 but I believe it should work on 10.x as well)
I think you're on the right track with LIKE. MySQL has an RLIKE function that allows matching by regular expression (I don't know if it's present in Oracle.) You could use errorlookup.code as a pattern to match against errors.errorcodes. The (..)* pattern is used to prevent things like "1213" from matching, for example, "21".
SELECT *
FROM error
JOIN errorlookup
WHERE errorcodes RLIKE CONCAT('^(..)*',code)
ORDER BY id;
+------+----------+------+
| id | errorcode| code |
+------+----------+------+
| 1 | 11 | 11 |
| 2 | 1121 | 11 |
| 2 | 1121 | 21 |
| 3 | 21313245 | 21 |
| 3 | 21313245 | 31 |
| 3 | 21313245 | 32 |
| 4 | 21 | 21 |
+------+----------+------+