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I have a small table (10K records) in PostgreSQL of individuals that I want to randomly select an age+gender match from a big (100M records) table and get several additional columns about these people.
There are a couple of considerations:
I'd like an efficient solution as the table is kinda big
While unlikely, I don't want to accidentally select any people in the small table from records from the big table. While a complete without replacement would be ideal, I am OK with just removing all the people in small table from the big table.
The big table can have multiple records for everyone, thus a DISTINCT is needed.
Once I get the N random matches I have to rejoin the results to mybigtable in order to get additional columns that I want
In this database, I have privileges to create TEMP tables but I cannot load data from a CSV into them and I cannot create regular tables.
I have figured out (below) how to inefficiently randomly select N (in this case 3) records for one person.
What I really want to do is be able to generalize this so it randomly selects 10 records for the all the people in the table mymatch, matching on values age+gender. I can't quite understand how to move to this.
DROP TABLE IF EXISTS mybigtable; -- this is 100M
CREATE TEMPORARY TABLE mybigtable (ID varchar, eID varchar, age INT, gender VARCHAR);
INSERT INTO mybigtable VALUES
('1', 'aaa', 84, 'F'),('2', 'aaa', 16, 'M'),('3', 'aaa', 23, 'F'),('4', 'aaa', 16, 'F'),('5', 'aaa', 94, 'F'),('6', 'aaa', 91, 'F'),('7', 'aaa', 18, 'M'),('8', 'aaa', 57, 'F'),('9', 'aaa', 84, 'F'),('10', 'aaa', 80, 'M'),('11', 'aaa', 16, 'M'),('12', 'aaa', 46, 'M'),('13', 'aaa', 84, 'F'),('14', 'aaa', 16, 'M'),('15', 'aaa', 23, 'F'),('16', 'aaa', 84, 'F'),('17', 'aaa', 30, 'M'),('18', 'aaa', 15, 'M'),('19', 'aaa', 16, 'M'),('20', 'aaa', 23, 'F'),('21', 'aaa', 84, 'F'),('22', 'aaa', 14, 'M'),('23', 'aaa', 84, 'F'),('24', 'aaa', 57, 'M'),('25', 'aaa', 89, 'M'),('1', 'bbb', 83, 'F'),('2', 'bbb', 19, 'M'),('3', 'bbb', 64, 'F'),('4', 'bbb', 92, 'M'),('5', 'bbb', 23, 'F'),('6', 'bbb', 62, 'M'),('7', 'bbb', 43, 'M'),('8', 'bbb', 16, 'M'),('9', 'bbb', 93, 'M'),('10', 'bbb', 45, 'M'),('11', 'bbb', 96, 'M'),('12', 'bbb', 68, 'M'),('13', 'bbb', 16, 'M'),('14', 'bbb', 97, 'F'),('15', 'bbb', 31, 'M'),('16', 'bbb', 23, 'F'),('17', 'bbb', 32, 'F'),('18', 'bbb', 18, 'F'),
('19', 'bbb', 23, 'F'),('20', 'bbb', 16, 'M'),('21', 'bbb', 35, 'M'),('22', 'bbb', 84, 'F'),('23', 'bbb', 48, 'F'),('24', 'bbb', 73, 'F'),('25', 'bbb', 46, 'F'),('26', 'bbb', 16, 'M'),('27', 'bbb', 39, 'M'),('28', 'bbb', 86, 'M'),('29', 'bbb', 78, 'F'),('30', 'bbb', 28, 'M'),('31', 'bbb', 32, 'F'),('32', 'bbb', 43, 'M'),('33', 'bbb', 64, 'F'),('34', 'bbb', 26, 'M'),('35', 'bbb', 81, 'M'),('36', 'bbb', 84, 'F'),('37', 'bbb', 23, 'F'),('38', 'bbb', 49, 'F'),('39', 'bbb', 66, 'F'),('40', 'bbb', 23, 'F'),('41', 'bbb', 23, 'F'),('42', 'bbb', 16, 'M'),('43', 'bbb', 92, 'M'),
('44', 'bbb', 16, 'M'),('45', 'bbb', 62, 'M'),('46', 'bbb', 16, 'M'),('47', 'bbb', 24, 'M'),('48', 'bbb', 16, 'M'),('49', 'bbb', 94, 'F'),('50', 'bbb', 58, 'F'),('1', 'ccc', 69, 'F'),('2', 'ccc', 97, 'M'),('3', 'ccc', 84, 'F'),('4', 'ccc', 78, 'M'),('5', 'ccc', 84, 'F'),('6', 'ccc', 54, 'M'),('7', 'ccc', 21, 'M'),('8', 'ccc', 23, 'F'),('9', 'ccc', 26, 'M'),('10', 'ccc', 84, 'M'),('11', 'ccc', 84, 'F'),('12', 'ccc', 69, 'M'),('13', 'ccc', 74, 'M'),('14', 'ccc', 83, 'F'),('15', 'ccc', 97, 'M'),('16', 'ccc', 55, 'M'),('17', 'ccc', 23, 'F'),('18', 'ccc', 59, 'F'),('19', 'ccc', 23, 'F'),('20', 'ccc', 68, 'F'),('21', 'ccc', 23, 'F'),('22', 'ccc', 84, 'F'),('23', 'ccc', 63, 'M'),('24', 'ccc', 88, 'M'),('25', 'ccc', 70, 'M');
DROP TABLE IF EXISTS mymatch; -- this will be about 10000
CREATE TEMPORARY TABLE mymatch (ID varchar, eID varchar, age INT, gender VARCHAR);
INSERT INTO mymatch VALUES
('16', 'aaa', 84, 'F'),('8', 'bbb', 16, 'M'),('15', 'aaa', 23, 'F');
DROP TABLE IF EXISTS mynotin;
CREATE TEMPORARY TABLE mynotin (ID varchar, eID varchar, age INT, gender VARCHAR);
--Create a table that does not have the people of interest
INSERT INTO mynotin
SELECT DISTINCT ID, eID, age, gender
FROM mybigtable mbt
WHERE NOT EXISTS
(SELECT
FROM mymatch
WHERE mymatch.ID = mbt.ID AND mymatch.eID = mbt.eID);
--This is the SELECT statement to get 3 random rows. Eventually this has to go to a table so I can join it to mybigtable and get additional columns of interest for the matched people.
SELECT id, eid, age, gender
FROM (
SELECT
t.*,
row_number() OVER(partition by age, gender ORDER BY RANDOM()) rn -- is there a more efficient method
FROM mynotin t
WHERE age=84 AND gender='F') t -- These are the conditions I want to change to the table mymatch
WHERE rn <= 3; --three for the example this will change to 10
DROP TABLE IF EXISTS mybigtable, mymatch, mynotin;
This actually turned out easier than I thought ...
This bit
FROM mynotin t
WHERE age=84 AND gender='F') t
Needs to change to
FROM mynotin t
JOIN mymatch mm ON t.age=mm.age AND t.gender=mm.gender) t
I don´t know why SQL Developer returned "SQL command not properly ended" when i tried to add multiple rows. When i tried to insert one row, all was ok. Can somebody help me? Thanks.
INSERT INTO TEAMS (TEAM_ID, NAME, POSITION, PLAYED, WIN, LOSE, DRAW, GF, GA, GD, POINTS)
VALUES
('MUN','MANCHESTER UNITED', 2, 29, 16, 9, 4, 56, 32, 24, 57),
('LEI','LEICESTER CITY', 3, 29, 17, 5, 7, 53, 32, 21, 56),
('CHE','CHELSEA', 4, 29, 14, 9, 6, 44, 25, 19, 51); ```
Oracle require separate insert statements. VALUES can only be used for a single row. Alternatively, you can use INSERT . . . SELECT:
INSERT INTO TEAMS (TEAM_ID, NAME, POSITION, PLAYED, WIN, LOSE, DRAW, GF, GA, GD, POINTS)
SELECT 'MUN','MANCHESTER UNITED', 2, 29, 16, 9, 4, 56, 32, 24, 57 FROM DUAL UNION ALL
SELECT 'LEI','LEICESTER CITY', 3, 29, 17, 5, 7, 53, 32, 21, 56 FROM DUAL UNION ALL
SELECT 'CHE','CHELSEA', 4, 29, 14, 9, 6, 44, 25, 19, 51 FROM DUAL;
I'm new to SQL and I need to check whether or not values in a row exist before I insert them.
I am attempting to insert details to several rows at once.
The code I have is as follows:
insert into [Test].[Projects]([TestID], [GroupID], [TestingID], [Grade])
values
(314, 9, 77, 2)
,(314, 9, 77, 3)
,(314, 9, 77, 4)
,(329, 2, 65, 2)
,(329, 2, 65, 3)
,(329, 2, 65, 4)
go
If someone could help me to insert these where the row values do not exist then I would be very grateful
You could use the insert ... select syntax with a not exists condition that ensures that the very same record is not already there in the table:
insert into Test.Projects(TestID, GroupID, TestingID, Grade)
select v.*
from (values
(314, 9, 77, 2),
(314, 9, 77, 3),
(314, 9, 77, 4),
(329, 2, 65, 2),
(329, 2, 65, 3),
(329, 2, 65, 4)
) v(TestID, GroupID, TestingID, Grade)
where not exists (
select 1
from Test.Projects p
where
p.TestID = v.TestID
and p.GroupID = v.GroupID
and p.TestingID = v.TestingID
and p.Grade = v.Grade
)
Good evening everyone,
I'm working on a assignment and can't figure out the following, I have two tables:
CREATE TABLE Rental (
rental_id DECIMAL(12) PRIMARY KEY,
customer_id DECIMAL(12),
movie_id DECIMAL(12),
delivery_status VARCHAR(64),
return_status VARCHAR(64));
and
CREATE TABLE Movie (
movie_id DECIMAL(12) PRIMARY KEY,
DVD_id INTEGER NOT NULL,
title VARCHAR(64) NOT NULL,
stock_number DECIMAL(12),
director_id DECIMAL(12),
genre_id DECIMAL(12),
release_date DATE NOT NULL,
restrictions VARCHAR(256) NOT NULL);
I need to do the following, list the names of all movies that are currently unavailable, rented and not yet returned. And this is my query:
SELECT Movie.movie_id, Movie.title, Movie.stock_number
FROM Movie
WHERE (Movie.movie_id, Movie.stock_number) NOT IN (
SELECT Rental.movie_id,
COUNT(Rental.return_status) AS number_of_unreturned
FROM Rental
WHERE Rental.return_status = 'Unreturned'
GROUP BY Rental.movie_id
HAVING COUNT (Rental.return_status) > 1) AND Movie.stock_number = 0;
I definitely have movies in Movie table that are not "Unreturend" but I get no rows selected all the time. Any advices or directions to think would be appreciated. Thanks!
I edited this post and added the content of the tables.
INSERT INTO Movie VALUES (1, 1, 'Amblin', 1, 1, 1, CAST('18-Dec-1968' AS DATE), 'G');
INSERT INTO Movie VALUES (2, 2, 'Duel', 2, 1, 2, CAST('13-Nov-1971' AS DATE), 'R');
INSERT INTO Movie VALUES (3, 3, 'Something Evil ', 3, 1, 3, CAST('21-Jan-1972' AS DATE), 'R');
INSERT INTO Movie VALUES (4, 4, 'The Sugarland Express ', 4, 1, 4, CAST('05-Apr-1974' AS DATE), 'PG13');
INSERT INTO Movie VALUES (5, 5, 'Jaws', 5, 1, 3, CAST('20-Jun-1975' AS DATE), 'R');
INSERT INTO Movie VALUES (6, 6, 'Close Encounters of the Third Kind', 6, 1, 5, CAST('16-Nov-1977' AS DATE), 'PG13');
INSERT INTO Movie VALUES (7, 7, ' 1941', 7, 1, 6, CAST('14-Dec-1979' AS DATE), 'G');
INSERT INTO Movie VALUES (8, 8, 'Raiders of the Lost Ark', 8, 1, 7, CAST('12-Jun-1981' AS DATE), 'PG13');
INSERT INTO Movie VALUES (9, 9, 'E.T. the Extra-Terrestrial', 9, 1, 5, CAST('11-Jun-1982' AS DATE), 'PG13');
INSERT INTO Movie VALUES (10, 10, 'Twilight Zone: The Movie', 10, 1, 3, CAST('24-Jun-1983' AS DATE), 'R');
INSERT INTO Movie VALUES (11, 11, 'Indiana Jones and the Temple of Doom', 11, 1, 7, CAST('23-May-1984' AS DATE), 'PG13');
INSERT INTO Movie VALUES (12, 12, 'The Color Purple', 12, 1, 4, CAST('18-Dec-1985' AS DATE), 'G');
INSERT INTO Movie VALUES (13, 13, 'Empire of the Sun', 13, 1, 4, CAST('25-Dec-1987' AS DATE), 'G');
INSERT INTO Movie VALUES (14, 14, 'Always', 14, 1, 4, CAST('22-Dec-1989' AS DATE), 'G');
INSERT INTO Movie VALUES (15, 15, 'Indiana Jones and the Last Crusade', 15, 1, 7, CAST('24-May-1989' AS DATE), 'G');
INSERT INTO Movie VALUES (16, 16, 'Hook', 16, 1, 8, CAST('11-Dec-1991' AS DATE), 'G');
INSERT INTO Movie VALUES (17, 17, 'Jurassic Park ', 17, 1, 5, CAST('11-Jun-1993' AS DATE), 'PG13');
INSERT INTO Movie VALUES (18, 18, 'Schindler''s List', 18, 1, 4, CAST('15-Dec-1993' AS DATE), 'PG13');
INSERT INTO Movie VALUES (19, 19, 'The Lost World: Jurassic Park', 19, 1, 5, CAST('23-May-1997' AS DATE), 'PG13');
INSERT INTO Movie VALUES (20, 20, 'Amistad', 20, 1, 4, CAST('10-Dec-1997' AS DATE), 'PG13');
INSERT INTO Movie VALUES (21, 21, 'Saving Private Ryan', 21, 1, 4, CAST('24-Jul-1998' AS DATE), 'PG13');
INSERT INTO Movie VALUES (22, 22, 'A.I. Artificial Intelligence', 22, 1, 4, CAST('29-Jun-2001' AS DATE), 'PG13');
INSERT INTO Movie VALUES (23, 23, 'Minority Report', 23, 1, 7, CAST('21-Jun-2002' AS DATE), 'PG13');
INSERT INTO Movie VALUES (24, 24, 'Catch Me If You Can', 24, 1, 8, CAST('25-Dec-2002' AS DATE), 'PG13');
INSERT INTO Movie VALUES (25, 25, ' The Terminal', 25, 1, 4, CAST('18-Jun-2004' AS DATE), 'G');
INSERT INTO Movie VALUES (26, 26, 'War of the Worlds', 26, 1, 5, CAST('29-Jun-2005' AS DATE), 'PG13');
INSERT INTO Movie VALUES (27, 27, 'Munich', 27, 1, 4, CAST('23-Dec-2005' AS DATE), 'PG13');
INSERT INTO Movie VALUES (28, 28, 'Indiana Jones and the Kingdom of the Crystal Skull', 28, 1, 7, CAST('22-May-2008' AS DATE), 'PG13');
INSERT INTO Movie VALUES (29, 29, 'The Adventures of Tintin', 28, 1, 7, CAST('21-Dec-2011' AS DATE), 'PG13');
INSERT INTO Movie VALUES (30, 30, 'War Horse', 30, 1, 4, CAST('25-Dec-2011' AS DATE), 'PG13');
INSERT INTO Movie VALUES (31, 31, 'Lincoln', 31, 1, 4, CAST('09-Nov-2012' AS DATE), 'PG13');
INSERT INTO Movie VALUES (32, 32, 'Bridge of Spies', 32, 1, 4, CAST('16-Oct-2015' AS DATE), 'PG13');
INSERT INTO Movie VALUES (33, 33, 'The BFG', 33, 1, 8, CAST('01-Jul-2016' AS DATE), 'PG13');
INSERT INTO Movie VALUES (34, 34, 'Praying with Anger', 34, 2, 5, CAST('12-Sep-1992' AS DATE), 'PG13');
INSERT INTO Movie VALUES (35, 35, 'Wide Awake', 35, 2, 4, CAST('20-Mar-1998' AS DATE), 'G');
INSERT INTO Movie VALUES (36, 36, 'The Sixth Sense', 36, 2, 2, CAST('06-Aug-1999' AS DATE), 'PG13');
INSERT INTO Movie VALUES (37, 37, 'Unbreakable', 37, 2, 2, CAST('22-Nov-2000' AS DATE), 'PG13');
INSERT INTO Movie VALUES (38, 38, 'Signs', 38, 2, 2, CAST('02-Aug-2002' AS DATE), 'PG13');
INSERT INTO Movie VALUES (39, 39, 'The Village', 39, 2, 2, CAST('30-Jul-2004' AS DATE), 'PG13');
INSERT INTO Movie VALUES (40, 40, 'Lady in the Water', 40, 2, 8, CAST('21-Jul-2006' AS DATE), 'PG13');
INSERT INTO Movie VALUES (41, 41, 'The Happening', 41, 2, 2, CAST('13-Jun-2008' AS DATE), 'R');
INSERT INTO Movie VALUES (42, 42, 'The Last Airbender', 42, 2, 7, CAST('02-Jul-2010' AS DATE), 'G');
INSERT INTO Movie VALUES (43, 43, 'After Earth', 43, 2, 7, CAST('31-May-2013' AS DATE), 'G');
INSERT INTO Movie VALUES (44, 44, 'The Visit', 44, 2, 3, CAST('11-Sep-2015' AS DATE), 'R');
INSERT INTO Movie VALUES (45, 45, 'Split', 45, 2, 2, CAST('20-Jan-2017' AS DATE), 'PG13');
and
INSERT INTO Rental VALUES (sequence_rental.NEXTVAL, 1, 1, 'Delivered', 'Unreturned');
INSERT INTO Rental VALUES (sequence_rental.NEXTVAL, 2, 1, 'Delivered', 'Unreturned');
INSERT INTO Rental VALUES (sequence_rental.NEXTVAL, 3, 6, 'Delivered', 'Unreturned');
INSERT INTO Rental VALUES (sequence_rental.NEXTVAL, 4, 7, 'Delivered', 'Unreturned');
INSERT INTO Rental VALUES (sequence_rental.NEXTVAL, 2, 2, 'Delivered', 'Unreturned');
INSERT INTO Rental VALUES (sequence_rental.NEXTVAL, 2, 37, 'Delivered', 'Unreturned');
INSERT INTO Rental VALUES (sequence_rental.NEXTVAL, 5, 1, 'Delivered', 'Unreturned');
INSERT INTO Rental VALUES (sequence_rental.NEXTVAL, 5, 24, 'Delivered', 'Unreturned');
INSERT INTO Rental VALUES (sequence_rental.NEXTVAL, 5, 3, 'Delivered', 'Unreturned');
INSERT INTO Rental VALUES (sequence_rental.NEXTVAL, 6, 13, 'Delivered', 'Unreturned');
INSERT INTO Rental VALUES (sequence_rental.NEXTVAL, 6, 2, 'Delivered', 'Unreturned');
INSERT INTO Rental VALUES (sequence_rental.NEXTVAL, 6, 8, 'Delivered', 'Unreturned');
INSERT INTO Rental VALUES (sequence_rental.NEXTVAL, 6, 1, 'Delivered', 'Unreturned');
INSERT INTO Rental VALUES (sequence_rental.NEXTVAL, 5, 2, 'Delivered', 'Unreturned');
INSERT INTO Rental VALUES (sequence_rental.NEXTVAL, 5, 3, 'Delivered', 'Unreturned');
INSERT INTO Rental VALUES (sequence_rental.NEXTVAL, 3, 27, 'Delivered', 'Returned');
Sorry if that is a too long post.
I don't want to write the code since you are a student. I'll give some direction though. In your where clause you're comparing (movie.movie_id = rental.movie_id) and (movie.stock_number = count(rental.return_status). Comparing the stock_number to the count of returns is incorrect.
When returning columns from multiple tables, use a join. The in statement does a comparison. Count is not being returned.
Join movies and the "in" subquery on movie_id. Create an alias on the subquery so you can join it.
Add the count column to the topmost outer select
Please try, if this logic is correct, I did not quite understand column naming. You might change last row (having) to correct it.
SELECT
m.movie_id, m.title, m.stock_number -- Getting movie id, movie title, stock number
FROM Movie m -- from movie table
JOIN rental r
ON (m.movie_id = r.movie_id) -- joining rental table in movie_id
WHERE
r.return_status = 'Unreturned' -- where return_status is unreturned
GROUP BY
m.movie_id, m.title, m.stock_number -- grouping_by (same as select)
HAVING
SUM(r.movie_id) > m.stock_number; -- restricting group by quantity
To resolve the query try first to break it down in the components you need.
In this case you need to compare the number of rented movies against the stock of movies.
So write 2 separte queries:
1 - One that will provide the movie id and the number to movies in stock.
2 - Another for the movie id and the number of rentals. For this one you have to count the unretured.
After you have the two queries, you can use them as subqueries of a higer level query that treats each or these queries as a table joined by the common id field.
And add awhere clause comparing the stock with the counted field.
Example:
Table A: id, name, age
Table B: table_b_id, table_a_id, telephone, address
Query 1: select id, name, age from A
Query 2: select table_a_id, telephone, address from B
select Q1.id, Q1.name, Q1.age, Q2telephone, Q2.address
from
(select A.id, A.name, A.age from A) Q1,
(select B.table_a_id, B.telephone, B.address from B) Q2
where
Q1.id = Q2.table_a_id
I'm trying to create a calculated column in SQL. Basically I need to get a set of distinct dates and determine how many customers there are in the population on that particular date. The result should be something like:
Date______| Customers
2016-01-01 | 1
2016-01-01 | 2
2016-01-05 | 3
2016-02-09 | 4
etc.
I created a sample database & data (using MySQL as I don't have permission to create tables in our Oracle dbs) with the following script:
create database customer_example;
use customer_example;
create table customers (
customer_id int not null primary key,
customer_name varchar(255) not null,
term_date DATE);
create table employee (
employee_id int not null primary key,
employee_name varchar(255) not null);
create table cust_emp (
ce_id int not null AUTO_INCREMENT,
emp_id int not null,
cust_id int not null,
start_date date,
end_date date,
deleted_yn boolean,
primary key (emp_id, cust_id, ce_id),
foreign key (cust_id) references customers(customer_id),
foreign key (emp_id) references employee(employee_id));
insert into customers (customer_id, customer_name)
values (1, 'Bobby Tables'), (2, 'Grover Cleveland'), (3, 'Chester Arthur'), (4, 'Jan Bush'), (5, 'Emanuel Porter'), (6, 'Darren King'), (7, 'Casey Mcguire'), (8, 'Robin Simpson'), (9, 'Robin Tables'), (10, 'Mitchell Arnold');
insert into customers (customer_id, customer_name, term_date)
values (11, 'Terrell Graves', '2017-01-01'), (12, 'Richard Wagner', '2016-10-31'), (13, 'Glenn Saunders', '2016-11-19'), (14, 'Bruce Irvin', '2016-03-11'), (15, 'Glenn Perry','2016-06-06'), (16, 'Hazel Freeman', '2016-07-10'),
(17, 'Martin Freeman', '2016-02-11'), (18, 'Morgan Freeman', '2017-02-01'), (19, 'Dirk Drake', '2017-01-12'), (20, 'Fraud Fraud', '2016-12-31');
insert into employee (employee_id, employee_name)
values (1000, 'Cedrick French'), (1001, 'Jane Phillips'), (1002, 'Brian Green'), (1003, 'Shawn Brooks'), (1004, 'Clarence Thomas');
insert into cust_emp (emp_id, cust_id, start_date, end_date)
values (1000, 1, '2016-01-01', '2016-02-01'), (1000, 1, '2016-02-01', '2016-02-01'), (1000, 2,'2016-01-05', '2016-01-16'),(1000, 3,'2016-02-09', '2016-03-14'),(1000, 4,'2016-03-20', '2016-04-23'),
(1000, 5,'2016-01-01', '2016-01-16'),(1000, 6,'2016-01-01', '2016-01-16'),(1004, 7, '2016-01-14', '206-01-16'),
(1004, 8, '2016-01-13', '2016-01-16'),(1004, 9, '2016-01-05', '2016-01-16'), (1003, 12, '2016-04-21', '2016-11-30');
insert into cust_emp (emp_id, cust_id, start_date, deleted_yn)
values (1002, 11, '2016-04-10', TRUE),(1003, 10, '2016-01-16', FALSE), (1004, 12, '2016-04-20', TRUE), (1004, 12, '2016-04-19', FALSE), (1003, 13, '2016-06-06', TRUE), (1002, 14, '2016-06-10', TRUE),
(1004, 15, '2016-03-25', TRUE), (1004, 17, '2016-01-02', TRUE), (1004, 18, '2017-01-01', TRUE), (1004, 19, '2016-11-13', TRUE), (1004, 20, '2016-03-10', TRUE), (1004, 16, '2016-05-13', TRUE);
insert into cust_emp (emp_id, cust_id, start_date)
values (1002, 1, '2016-02-01'), (1004, 2, '2016-01-16'),(1003, 3, '2016-03-14'),(1002, 4, '2016-04-23'),(1004, 5, '2016-01-16'),(1002, 6, '2016-01-16'),(1004, 7, '2016-01-16'),
(1004, 8, '2016-01-16'),(1002, 9, '2016-01-16'), (1004, 10, '2016-01-16');
The following SQL works fine in MySQL but when I try it in Oracle, I get an 'invalid identifier' on 'dates':
select distinct(ce.start_date) as dates,
(select count(distinct(c.customer_id))
from customers c
inner join cust_emp ce on c.customer_id = ce.cust_id
where ce.start_date < dates
and (ce.end_date > dates or (ce.deleted_yn = false or ce.deleted_yn is null))
and (c.term_date > dates or c.term_date is null)
)
from cust_emp as ce;
It seems as though this is because the dates is too far in a subquery. I've tried a CTE as well, but that seems to have the same issue as it gave the same error. How can I re-write this so that I can assess how many customers were there for each date in Oracle?
Huh?
Isn't this what you want?
select ce.dates as dates, count(distinct c.customer_id)
from cust_emp ce join
customers c
on c.customer_id = ce.cust_id
where ce.start_date < ce.dates and
(ce.end_date > ce.dates or ce.deleted_yn = false or ce.deleted_yn is null) and
(c.term_date > ce.dates or c.term_date is null)
group by ce.dates
order by ce.dates;
I don't really understand the use of the subquery with select distinct. The logic you describe is more easily understood as a simple aggregation.
I'm not sure where dates comes from. It is not in your data model, but it is in your sample query.