I want to have the following two tables:
CREATE TABLE buildings
(
ID int IDENTITY NOT NULL PRIMARY KEY,
city_ID int NOT NULL REFERENCES(cities),
name char(20) NOT NULL
)
CREATE TABLE cities
(
ID int IDENTITY NOT NULL PRIMARY KEY,
name char(30) NOT NULL
)
INSERT INTO cities (name) VALUES ('Katowice')
Now I need that when I write:
INSERT INTO buildings (city_ID,name) values (1,'bahnhof')
makes the same effect that when I write:
INSERT INTO buildings VALUES ('Katowice','bahnhof')
My purpose is that when I want to add building to a city, I think about city name, not its ID in cities table. But sometimes I remember ID, and then I prefer to use ID. Is it possible without creating a procedure?
I am thinking about appropriate procedure:
CREATE PROCEDURE addbuilding
#city_ID int,
#name char
AS
BEGIN
INSERT INTO buildings (city_ID,name) VALUES (#city_ID,#name)
END
But as we can see above, #city_ID can be only int. Something like union in C++ could be a good solution, but is it possible in SQL?
I'm not sure if SQL procedures support union similarly to C++ as you ask, but my suggestion would be a rather simple one: two procedures.
CREATE PROCEDURE add_building_by_city_id
#city_ID int,
#name char
etc
CREATE PROCEDURE add_building_by_city_name
#city_name char,
#name char
etc
And then you could use whichever one you need. Of course that the second procedure would need a simple SELECT first, to find the city by its name and retrieve its ID.
Related
I have two related tables something like this:
CREATE TABLE test.items
(
id INT identity(1,1) PRIMARY KEY,
type VARCHAR(max),
price NUMERIC(6,2)
);
CREATE TABLE test.books
(
id INT PRIMARY KEY REFERENCES test.items(id),
title VARCHAR(max),
author VARCHAR(max)
);
Is it possible to insert into both tables using a single SQL statement?
In PostgreSQL, I can use something like this:
-- PostgreSQL:
WITH item AS (INSERT INTO test.items(type,price) VALUES('book',12.5) RETURNING id)
INSERT INTO test.books(id,title) SELECT id,'Good Omens' FROM item;
but apparently SQL Server limits CTEs to SELECT statements, so that won’t work.
In principle, I could use the OUTPUT clause this way:
-- SQL Server:
INSERT INTO test.items(type, price)
OUTPUT inserted.id, 'Good Omens' INTO test.books(id,title)
VALUES ('book', 12.5);
but this doesn’t work if there’s a foreign key involved, as above.
I know about using variables and procedures, but I wondered whether there is a simple single-statement approach.
You can using dynamic sql as follows. Although its awkward to construct query like this.
CREATE TABLE dbo.items (
id INT identity(1,1) PRIMARY KEY,
type VARCHAR(max),
price NUMERIC(6,2)
);
CREATE TABLE dbo.books (
id INT PRIMARY KEY REFERENCES dbo.items(id),
title VARCHAR(max),
author VARCHAR(max)
);
insert into dbo.books(id,title)
exec ('insert into dbo.items(type,price) output inserted.id,''Good Omen'' VALUES(''book'',12.5)')
EDIT: I revised my original question for clarity. Hopefully this helps explain what I'm trying to accomplish more clearly.
I have a standard SQL table VEHICLES and I changed its name to OLTP_VEHICLES with a RENAME statement.
I created a new VEHICLES table as a dimension table that is the "beginning" of my star schema for this DB.
I now need to accomplish the following:
"For the vehicleCode primary key column, use an Oracle Sequence to populate the values. For the vehicleDescription column, use a concatenated combination of vehicleMake and vehicleModel from the OLTP_VEHICLES table."
I need to accomplish this by using a PL/SQL block to populate the description column by selecting the vehicleMake and vehicleModel from the OLTP_VEHICLES table and then inserting the concatenated combination into the VEHICLES Dimension table, via a cursor in a loop.
With this instruction, I am totally baffled. I think where I was confusing you fine folks before was the fact that I was leaving out the "second part" involving the insertion of the vehicleMake and vehicleModel concatenation.
Does this help explain better what I'm after? If not, I'm deeply sorry. I'm so confused on this that I'm even having trouble explaining it. Thanks again for your assistance.
CREATE TABLE VEHICLES
(vehicleVIN VARCHAR(25) PRIMARY KEY,
vehicleType VARCHAR(10) NOT NULL CHECK (lower(vehicleType) IN ('compact', 'midsize', 'fullsize', 'suv', 'truck')),
vehicleMake VARCHAR(15) NOT NULL,
vehicleModel VARCHAR(15) NOT NULL,
vehicleWhereFrom VARCHAR(20) NOT NULL CHECK (lower(vehicleWhereFrom) IN ('maryland','virginia','washington, d.c.')),
vehicleWholesaleCost DECIMAL(9,2) NOT NULL,
vehicleTradeID INT);
INSERT INTO VEHICLES
(vehicleVIN,vehicleType,vehicleMake,vehicleModel,vehicleWhereFrom,vehicleWholesaleCost,vehicleTradeID)
VALUES
('147258HHE91K3RT','compact','chevrolet','spark','Maryland',20583.00,NULL);
INSERT INTO VEHICLES
(vehicleVIN,vehicleType,vehicleMake,vehicleModel,vehicleWhereFrom,vehicleWholesaleCost,vehicleTradeID)
VALUES
('789456ERT0923RFB6','Midsize','ford','Taurus','washington, d.c.',25897.22,1);
INSERT INTO VEHICLES
(vehicleVIN,vehicleType,vehicleMake,vehicleModel,vehicleWhereFrom,vehicleWholesaleCost,vehicleTradeID)
VALUES
('1234567890QWERTYUIOP','fullsize','Lincoln','towncar','Virginia',44222.10,NULL);
INSERT INTO VEHICLES
(vehicleVIN,vehicleType,vehicleMake,vehicleModel,vehicleWhereFrom,vehicleWholesaleCost,vehicleTradeID)
VALUES
('WER234109TEO458GZ','SUV','Chevrolet','suburban','Maryland',52789.00,2);
ALTER TABLE VEHICLES RENAME TO OLTP_VEHICLES;
CREATE TABLE VEHICLES
(vehicleCode VARCHAR(25) PRIMARY KEY,
vehicleDescription VARCHAR(50) NOT NULL);
I also put this into SQL Fiddle if anyone wants to test something: http://sqlfiddle.com/#!4/2de3ae
Thanks!
Finally figured it out, after lots of research, trial and error, and of course, help from #MatBailie. Here's the solution I was after:
--Oracle sequence to populate primary key values in VEHICLES dimension table
DROP SEQUENCE SEQ_VEHICLES;
CREATE SEQUENCE SEQ_VEHICLES START WITH 1 INCREMENT BY 1;
CREATE OR REPLACE TRIGGER VEHICLES_PK
BEFORE INSERT ON VEHICLES FOR EACH ROW
BEGIN
SELECT SEQ_VEHICLES.NEXTVAL INTO :new.vehicleCode FROM DUAL;
END;
/
--PL/SQL Block to populate the description column via a cursor in a loop w/concatenation
DECLARE
CURSOR vehDesCur IS
SELECT LOWER(vehicleMake) || ' ' || LOWER(vehicleModel) AS vehicleDescription
FROM OLTP_VEHICLES;
BEGIN
FOR oltp_data IN vehDesCur
LOOP
INSERT INTO VEHICLES (vehicleDescription)
SELECT oltp_data.vehicleDescription
FROM dual
WHERE NOT EXISTS
(SELECT *
FROM VEHICLES v
WHERE v.vehicleDescription = oltp_data.vehicleDescription);
END LOOP;
END;
/
If I want to do something relatively complicated - something usually done by a stored procedure. Is it possible to make it automatic using a VIEW?
My specific case:
I want output table = input table A + some rows input table B. In a stored procedure, I can make a copy of table A and then INSERT INTO it, but it's not allowed in a view.
Simplified example:
input table is [test_album], and output table = input table + singer Prince.
--create test data
IF OBJECT_ID('[dbo].[test_album]', 'U') IS NOT NULL
DROP TABLE [dbo].[test_album]
CREATE TABLE [test_album] (
id int not null identity(1, 1) primary key,
singer VARCHAR(50) NULL,
album_title VARCHAR(100) NULL
)
INSERT INTO [test_album] (singer, album_title)
VALUES ('Adale', '19'),
('Michael Jaskson', 'Thriller')
--this can be executed as sql code or in stored proc
SELECT *
INTO [result_table]
FROM [test_album]
INSERT INTO [result_table] ([singer])
VALUES ('Prince')
select *
from [result_table]
--id singer album_title
--1 Adale 19
--2 Michael Jaskson Thriller
--3 Prince NULL
----as expected
But I can do this INSERT INTO inside a view.
Real-life case:
additional singers are in a table [extra_singers]
[test_album] may have many other columns (or schema may change) so it's ideal not to type all column names in the code.
--create test data
IF OBJECT_ID('[dbo].[test_album]', 'U') IS NOT NULL
DROP TABLE [dbo].[test_album]
IF OBJECT_ID('[dbo].[extra_singers]', 'U') IS NOT NULL
DROP TABLE [dbo].[extra_singers]
IF OBJECT_ID('[dbo].[result_table]', 'U') IS NOT NULL
DROP TABLE [dbo].[result_table]
CREATE TABLE [test_album] (
id int not null identity(1, 1) primary key,
singer VARCHAR(50) NULL,
album_title VARCHAR(100) NULL,
many_other_columns VARCHAR(100) NULL
)
INSERT INTO [test_album] (singer, album_title)
VALUES ('Adale', '19'),
('Michael Jaskson', 'Thriller')
CREATE TABLE [extra_singers] (
[id] int not null identity(1, 1) primary key,
[name] VARCHAR(50) NULL )
INSERT INTO [extra_singers] ([name])
VALUES ('Prince'),
('Taylor Swift')
--append [extra_singers] to [test_album]
--this can be executed as sql code or in stored proc
SELECT *
INTO [result_table]
FROM [test_album]
INSERT INTO [result_table] ([singer])
SELECT [name]
FROM [extra_singers]
Is there an alternative to this (that is automatic)?
any help's appreciated. Thank u-
a partial solution I can think of:
create view test_view as
select *
from [test_album]
union all
select 3 as id,
'Prince' as singer,
NULL as album_title
but you have to know all the column names in [test_album] and you can't let column [id] do auto-increment
So you may be misunderstanding what a view does, or what an insert is. A view is simply a wrapper around a single select query. It contains exactly one select statement, and nothing else. An insert permanently adds a row of data to a persisted table. The example you gave where you just union the row you want seems valid enough. And certainly if it's the same row you want every time, you would not want to be inserting (or even trying to insert) that row into the underlying table each time
This raises a couple questions though.
If you're always going to be unioning the same single row every time, why not jut add that row to the table?
If, lets say, you don't want that row in the underlying table, cool. But if it's always the same static values, why do you need to include it in the view? Can't it just be assumed it's there?
If it can't be assume to always be the same, you certainly don't want to be changing the VIEW body every time you need it to change. So if it is going to change and you don't want to insert it into the base table, maybe make a second table containing the values you want appended to the base table in the view. Then union the base table and the "extra values" table together instead of a single, hard coded row constructor.
Lets say I have a CREATE TABLE code like this:
CREATE TABLE Test (
ID int NOT NULL IDENTITY(1,1),
SortIndex int,
Name nvarchar(50) NOT NULL
);
I was wondering if it's possible to make a table in MSSQL which had the ability to insert the ID's value into the SortIndex column when I run an INSERT.
So I would run this INSERT:
INSERT INTO Test (Name) VALUES ('Awesome Dude');
Which would normally yield the row:
ID,SortIndex,Name
1,NULL,"Awesome Dude"
But I'd like it to automatically be:
ID,SortIndex,Name
1,1,"Awesome Dude"
Is this even possible by altering the CREATE TABLE script, or do I have to use a TRIGGER?
I would be inclided to take a slightly different approach to this. If you want your SortIndex to default to the ID, but be overridable, I would use a nullable column, and a computed column:
CREATE TABLE Test (
ID int NOT NULL IDENTITY(1,1),
OverrideSortIndex int,
Name nvarchar(50) NOT NULL,
SortIndex AS ISNULL(OverrideSortIndex, ID)
);
If you need to change the sort index for any reason, update the column OverrideSortIndex and this takes precedence.
I've created a insert stored procedure with two tables like in the exapmle:
Table NameAge
CREATE TABLE [dbo].[Assignment3_NameAge]
(
userID int PRIMARY KEY IDENTITY(1,1),
Name varchar(255) NOT NULL,
Age int NOT NULL
)
Table Hobbies
CREATE TABLE [dbo].[Assignment3_Hobbies]
(
hobbiesID int Identity(1,1) Primary Key,
userID int Foreign Key references Assignment3_NameAge(userID),
hobbies varchar(255) NOT NULL,
)
Insert Stored Procedure
CREATE PROCEDURE [dbo].p_Assignment3Join_ins
#Name nvarchar(100),
#Age int,
#Hobbies nvarchar(100)
AS
INSERT INTO [TABLE].[dbo].[Assignment3_NameAge]
([Name]
,[Age])
VALUES (#Name,#Age)
INSERT INTO [TABLE].[dbo].[Assignment3_Hobbies]
([Hobbies])
VALUES (#Hobbies)
The problem is that when i run the stored procedure the table Hobbies has a null value for userid(the foreign key)
What am i doing wrong?
You should provide the key of the Assignment3_NameAge value you want to insert into Assignment3_Hobbies.
If you want the last inserted you can use SCOPE_IDENTITY() from SQL Server(if you're using SQL Server) or equivalent. It will give you the last inserted value from Assignment3_NameAge
I am guessing this is SQL Server based on the IDENTITY column. Correct?
The first insert creates a user, but there is no user ID being set on the insert of the hobby. You need to capture the identity value from the first insert to be used in the second insert. Have you gon over the system functions available?
You're not supplying a value for it, SQL won't automagically fill the value in for you even though you've created a Foreign Key relationship. It's your job to populate the tables.