I want to grab values from a nested table in one table and insert said values into another table
Here's the type for the nested table:
CREATE OR REPLACE TYPE type_val AS OBJECT
(
year DATE,
amount INTEGER
);
The nested table:
CREATE OR REPLACE TYPE nt_type_val IS
TABLE OF type_val;
Here's the table that contains the nested table:
CREATE TABLE country
(
id INTEGER NOT NULL,
name VARCHAR2(100) NOT NULL,
continent VARCHAR2(30) NOT NULL,
prod_an nt_type_val
)
NESTED TABLE prod_an STORE AS nt_prod_an;
Here's the table into which I want to insert
CREATE TABLE prod_country_ai
(
year DATE NOT NULL,
amount INTEGER NOT NULL,
country_fk INTEGER NOT NULL
)
What I want to do is I want to grab the values from prod_an in the country table for each country and store them in the prod_country_ai table, respectively, year and amount from the nested table (prod_an) into year and amount on prod_country_ai and the primary key from country into country_fk on prod_country_ai.
I have the following piece for a procedure that would do that:
DECLARE
CURSOR inner_table IS
SELECT t.* FROM country p, TABLE(p.prod_an) t
WHERE p.name = 'Portugal';
BEGIN
FOR i IN inner_table LOOP
dbms_output.put_line( i.year || i.quantity);
END LOOP;
END;
This successfully outputs the year followed by the amount but it only does so upon specification of the country name, the solution I thought of is running an "outer loop" that cycles on the country table (could be by id or by country name it doesn't change much because each value will be unique either way), and I'm guessing I can use i.year and i.quantity directly on an insert statement inside the "inner loop" to insert into prod_country_ai, but I'm not sure how I can do this, also, I think variables are treated as "local" inside a loop so how could I go about inserting the country primary key as a foreign key in the prod_country_ai table?
You don't need a procedure for this. You can do this with an INSERT ... SELECT from the countries cross joining the nested tables.
INSERT INTO prod_country_ai (year, amount, country_fk)
SELECT
p.year, p.amount, c.id
FROM
country c
CROSS JOIN TABLE(c.prod_an) p;
Related
Need to find out why my group by count query is not working. I am using Microsoft SQL Server and there are 2 tables I am trying to join.
My query needs to bring up the number of transactions made for each type of vehicle. The output of the query needs to have a separate row for each type of vehicle such as ute, hatch, sedan, etc.
CREATE TABLE vehicle
(
vid INT PRIMARY KEY,
type VARCHAR(30) NOT NULL,
year SMALLINT NOT NULL,
price DECIMAL(10, 2) NOT NULL,
);
INSERT INTO vehicle
VALUES (1, 'Sedan', 2020, 240)
CREATE TABLE purchase
(
pid INT PRIMARY KEY,
vid INT REFERENCES vehicle(vid),
pdate DATE NOT NULL,
datepickup DATE NOT NULL,
datereturn DATE NOT NULL,
);
INSERT INTO purchase
VALUES (1, 1, '2020-07-12', '2020-08-21', '2020-08-23')
I have about 10 rows on information in each table I just haven't written it out.
This is what I wrote but it doesn't return the correct number of transactions for each type of car.
SELECT
vehicle.vid,
COUNT(purchase.pid) AS NumberOfTransactions
FROM
purchase
JOIN
vehicle ON vehicle.vid = purchase.pid
GROUP BY
vehicle.type;
Any help would be appreciated. Thanks.
Your GROUP BY and SELECT columns are inconsistent. You should write the query like this:
SELECT v.Type, COUNT(*) AS NumPurchases
FROM Purchase p JOIN
Vehicle v
ON v.vID = p.pID
GROUP BY v.Type;
Note the use of table aliases so the query is easier to write and read.
If this doesn't produce the expected values, you will need to provide sample data and desired results to make it clear what the data really looks like and what you expect.
There are two tables:
Table education_data (list of countries with values by year per measured indicator).
create table education_data
(country_id int,
indicator_id int,
year date,
value float
);
Table indicators (list of all indicators):
create table indicators
(id int PRIMARY KEY,
name varchar(200),
code varchar(25)
);
I want to find the indicators for which the highest number of countries lack information entirely
i.e. max (count of missing indicators by country)
I have solved the problem in excel (by counting blanks in a pivot table by country)
pivot table with count for missing indicators by country
I haven't figured our yet the SQL query to return the same results.
I am able to return the number of missing indicators for a set country , read query below, but not for all countries.
SELECT COUNT(*)
FROM education_data AS edu
RIGHT JOIN indicators AS ind ON
edu.indicator_id = ind.id and country_id = 10
WHERE value IS NULL
GROUP BY country_id
I have tried with a cross join without success so far.
You will have to join on the contries as well, otherwise you can not tell if a contry has no entry in education_data at all:
create table countries(id serial primary key, name varchar);
create table indicators
(id int PRIMARY KEY,
name varchar(200),
code varchar(25)
);
create table education_data
(country_id int references countries,
indicator_id int references indicators,
year date,
value float
);
insert into countries values (1,'USA');
insert into countries values (2,'Norway');
insert into countries values (3,'France');
insert into indicators values (1,'foo','xxx');
insert into indicators values (2,'bar', 'yyy');
insert into education_data values(1,1,'01-01-2020',1.1);
SELECT count (c.id), i.id, i.name
FROM countries c JOIN indicators i ON (true) LEFT JOIN education_data e ON(c.id = e.country_id AND i.id = e.indicator_id)
WHERE indicator_id IS NULL
GROUP BY i.id;
count | id | name
-------+----+------
3 | 2 | bar
2 | 1 | foo
(2 rows)
I want to find the indicators for which the highest number of countries lack information entirely i.e. max (count of missing indicators by country)
That's a logical contradiction. The ...
count of missing indicators by country
.. cannot be pinned on any specific indicators, since those countries don't have an indicator.
The counts per country with "missing indicator" (i.e. indicator_id IS NULL):
SELECT country_id, count(*) AS ct_indicator_null
FROM education_data
WHERE indicator_id IS NULL
GROUP BY country_id
ORDER BY count(*) DESC;
Or, more generally, without valid indicator, which also includes rows where indicator_id has no match in table indicators:
SELECT country_id, count(*) AS ct_no_valid_indicator
FROM education_data e
WHERE NOT EXISTS (
SELECT FROM indicators i
WHERE i.id = e.indicator_id
)
GROUP BY country_id
ORDER BY count(*) DESC;
NOT EXISTS is one of four basic techniques that apply here (LEFT / RIGHT JOIN, like you tried being another one). See:
Select rows which are not present in other table
You mentioned a country table. Countries without any indicator entries in education_data are not included in the result above. To find those, too:
SELECT *
FROM country c
WHERE NOT EXISTS (
SELECT
FROM education_data e
JOIN indicators i ON i.id = e.indicator_id -- INNER JOIN this time!
WHERE e.country_id = c.id
);
Reports countries without valid indicator (none, or not valid).
If every country should have a valid indicator, after cleaning up existing data, consider:
1: adding an FOREIGN KEY constraint to disallow invalid entries in education_data.indicator_id.
2: setting education_data.indicator_id NOT NULL to also disallow NULL entries.
Or add a PRIMARY KEY on (country_id, indicator_id), which makes both columns NOT NULL automatically.
.. which brings you closer to a valid many-to-many implementation. See:
How to implement a many-to-many relationship in PostgreSQL?
I have two tables:
Cust : Contains customer details like customer ID and customer Name.
Cust_Address : This table contains customer ID and customer address.
Table: Cust
create table cust
(
cust_id int,
cust_name varchar(10)
);
Records Insertion:
insert into cust values(1,'A');
insert into cust values(2,'B');
insert into cust values(3,'C');
insert into cust values(4,'D');
Table: Cust_Address
create table cust_address
(
cust_id int,
cust_add varchar(50)
);
Records Insertion:
insert into cust_address values(1,'US');
insert into cust_address values(2,'UK');
insert into cust_address values(3,'UAE');
insert into cust_address values(4,'SA');
insert into cust_address values(1,'AUS');
insert into cust_address values(2,'IND');
insert into cust_address values(3,'SL');
insert into cust_address values(1,'CHINA');
Now I want to show the result which contains the latest customer address which have been inserted in the table Cust_Address.
Expected Result:
Cust_ID Cust_Name Cust_Add
-------------------------------
1 A CHINA
2 B IND
3 C SL
4 D SA
Here is the SQLFiddle for tables and its records.
You are not able to retrieve the rows in any particular order. You need some more info to get an order.
The best way is primary index in Cust_address
CustAddrID int identity(1, 1) not null primary key
You can also have a CreatedOn column that will have default value equal to getDate()
After that you can figure out what is the last inserted value for CustAddr for each Cust record.
In case you are not able to add new column there then maybe
change tracking functionality. But your issue seems to be too trivial for that.
There are also Temporal Tables in SQL Server 2016. But again it's probably too much.
Here is an example how you can get the address using primary key CustAddrID
SQL Fiddle
select cust_name, cust_add
from cust C
join
(select
cust_add, cust_id,
row_number() over (partition by cust_id order by cust_add_id desc) rn
from cust_address ) CLA
on CLA.cust_id = C.cust_id and
CLA.rn = 1
Identity column increases every time when we insert new value to the table. The correct value for your case will be the record with the highest cust_add_id and specified cust_id.
In the above query we generates numbers in desc order starting from 1 using row_number() function for each cust_id (partition by cust_id). Finally we take only the records with generated number rn equal to 1 CLA.rn = 1 and we join it to cust table.
You can replace row_number() by max(cust_add_id) and group by cust_id. However in that case you need to join cust_add table twice.
You will not be able to get the rows out of the link table in the order they were inserted.
You need to have a column for this.
Imagine how big the meta-data would be if you needed to keep a record for each record for creation! Would you also want to keep meta-data on your meta-data so you know when the meta-data was updated? The space use can quickly escalate.
SQL Server keeps some stats but something this specific will need to come from a user-defined field.
So you either use a identity column in the CustAddr table [CustAddr int identity(1, 1) not null primary key] or add a column for createdDateAndTime DateTime Default GetDate().
CREATE TABLE Products (
ID int,
name VARCHAR(70),
price NUMBER(8,2),
primary key (ID, name)
);
drop table Instock;
/* Delete the tables if they already exist */
create table Instock (
ID int,
quantity int
);
I have two table in my database. i want to have two table showing a output as a table that look like this
ID Name Price Quantity
SELECT A.ID,A.NAME,A.PRICE,B.QUANTITY FROM Products A,Instock B WHERE A.ID=B.ID
You can try this to create the new table(this creates the table in addition to putting the data in there)
CREATE TABLE MY_TABLE as SELECT A.ID,A.NAME,A.PRICE,B.QUANTITY FROM Products A,Instock B WHERE A.ID=B.ID
I am an amateur just trying to finish his last question of his assignment (it is past due at this point, just looking for understanding) I sat and shot attempts at this for almost 5 hours now across two days, and have had no success.
I have tried looking through all the different types of joins, couldn't get grouping to work (ever) and have had little luck with the sorting as well. I can do all of these things one at a time, but the difficulty here was getting all of these things to work in union.
This is the question:
Write a SQL query to retrieve a list that has (source city, source code, destination city,
destination code, and number-of-flights) for all source-dest pairs with at least 2 flights. Order
by the number_of_flights. Note that the “dest”, and “source” attributes in the “flights” table
are both referenced to the “airportid” in the “airports” table.
Here are the tables I have to work with (also came with about 3000 lines of dummy entries)
create table airports (
airportid char(3) primary key,
city varchar(20)
);
create table airlines (
airlineid char(2) primary key,
name varchar(20),
hub char(3) references airports(airportid)
);
create table customers (
customerid char(10) primary key,
name varchar(25),
birthdate date,
frequentflieron char(2) references airlines(airlineid)
);
create table flights (
flightid char(6) primary key,
source char(3) references airports(airportid),
dest char(3) references airports(airportid),
airlineid char(2) references airlines(airlineid),
local_departing_time date,
local_arrival_time date
);
create table flown (
flightid char(6) references flights(flightid),
customerid char(10) references customers,
flightdate date
);
The first problem I ran in to was outputting airports.city twice in the same query but with different results. Not only that, but no matter what I tried when grouping I would always get the same result:
Not a GROUP BY expression
Normally I have fun trying to piece these together, but this has been frustrating. Help!
select source.airportid as source_airportid,
source.city source_city,
dest.airportid as dest_airportid,
dest.city as dest_city,
count(*) as flights
from flights
inner join airports source on source.airportid = flights.source
inner join airports dest on dest.airportid = flights.dest
group by
source.airportid,
source.city,
dest.airportid,
dest.city
having count(*) >= 2
order by 5;
Have you tried a subquery?
SELECT source_airports.city,
source_airports.airportid,
dest_airports.city,
dest_airports.airportid,
x.number_of_flights
FROM
(
SELECT source, dest, COUNT(*) as number_of_flights
FROM flights
GROUP BY source, dest
HAVING COUNT(*) > 1
) as x
INNER JOIN airports as dest_airports
ON dest_airports.airportid = x.dest
INNER JOIN airports as source_airports
ON source_airports.airportid = x.source
ORDER BY x.number_of_flights ASC