SELECT * FROM tbl_houses
WHERE
(SELECT HousesList
FROM tbl_lists
WHERE tbl_lists.ID = '123') LIKE CONCAT('% ', tbl_houses.ID, '#')
It only selects the row from tbl_houses of the last occuring tbl_houses.ID inside tbl_lists.HousesList
I need it to select all the rows where any ID from tbl_houses exists within tbl_lists.HousesList
It's hard to tell without knowing exactly what your data looks like, but if it only matches the last ID, it's probably because you don't have any % at the end of the string, so as to allow for the list to continue after the match.
Is that a database in zeroth normal form I smell?
If you have attributes containing lists of values, like that HousesList attribute, you should instead be storing those as distinct values in a separate relation.
CREATE TABLE house (
id VARCHAR NOT NULL,
PRIMARY KEY (id)
);
CREATE TABLE list (
id VARCHAR NOT NULL,
PRIMARY KEY (id),
);
CREATE TABLE listitem (
list_id VARCHAR NOT NULL,
FOREIGN KEY list_id REFERENCES list (id),
house_id VARCHAR NOT NULL,
FOREIGN KEY house_id REFERENCES house (id),
PRIMARY KEY (list_id, house_id)
);
Then your distinct house listing values each have their own tuple, and can be selected like any other.
SELECT house.*
FROM house
JOIN listitem
ON listitem.house_id = house.id
WHERE
listitem.list_id = '123'
Related
I keep getting the error:
Cannot add or update a child row: a foreign key constraint fails
(myWork.Bookingss, CONSTRAINT Bookingss_ibfk_1 FOREIGN KEY
(CustomersID) REFERENCES Customers (CustomersID))
I have spent a while researching as this is apart of a school assignment and can not seem to resolve the problem.
Here is my SQL code:
USE myWork ;
DROP TABLE IF EXISTS Bookingss ;
DROP TABLE IF EXISTS Customers ;
CREATE TABLE myWork.Customers
(
CustomersID INT NOT NULL AUTO_INCREMENT,
Surname CHAR(30) NOT NULL ,
FirstName CHAR(30) NOT NULL ,
Title CHAR(10),
DOB DATE,
HouseNumber INT,
StreetName CHAR(30),
Town CHAR(30),
PostCode CHAR(9),
Telephone INT,
PRIMARY KEY (CustomersID)
) ;
CREATE TABLE myWork.Bookingss
(
BookingsID INT NOT NULL AUTO_INCREMENT,
CustomersID INT NOT NULL,
AdultsBooked INT NOT NULL,
ChildrenBooked INT NOT NULL,
Check_In DATE,
Check_Out DATE,
PRIMARY KEY (BookingsID),
FOREIGN KEY (CustomersID)
REFERENCES myWork.Customers (CustomersID)
) ;
SHOW TABLES ;
INSERT INTO myWork.Bookingss ( CustomersID, AdultsBooked , ChildrenBooked , Check_In , Check_Out )
VALUES ("1", "2", "3", "2022-04-10", "2022-04-13" ) ;
INSERT INTO myWork.Customers ( Surname , FirstName , Title , DOB )
VALUES ( "smith" , "ryan" , "Mr" , "1998-02-16" ) ;
SELECT * FROM Customers , Bookingss;
You got the order wrong and some challenges to overcome. You are trying to insert a booking first, and this with an id for a customer that does not yet exist in the customer table at that moment.
You have to insert the customer first, then use the customer's id to insert the booking for the customer (using his id).
And there is the first challenge. The customer id is an auto increment field. You would not know the id when you insert a customer in the table.
You would have to fetch the customer and use the id of that customer to insert a booking for the customer. How do you fetch the customer? Selecting the customer with a specific name surname and first name is not a correct choice, any other field (or composition of fields) that I see in the table definition is not a good choice neither.
You'd need to think further about a good solution. There are several options I could tell you about. But the appropriate solution depends on your assignment/context.
By the way, the last select clause may not deliver the result you expect. You are producing a cartesian product (every row of the first table with every row of the second table). What you probably want is a JOIN where you link the first table with the second table accordingly (e.g. using the primary key and the foreign key).
After creating the table with a unique ID autoincrement, I realize my table lack a row. But I don't know how to do this without compromising the order of other rows in the table!
TABLE flights
id INTEGER PRIMARY KEY AUTOINCREMENT,
origin TEXT NOT NULL,
destination TEXT NOT NULL,
duration INTEGER NOT NULL
I want to insert a row: 2|Shanghai|Paris|760 into the table with id = 2.
1|New York|London|415
2|Istanbul|Tokyo|700
3|New York|Paris|435
4|Moscow|Paris|245
5|Lima|New York|455
Table I wished:
1|New York|London|415
2|Shanghai|Paris|760
3|Istanbul|Tokyo|700
4|New York|Paris|435
5|Moscow|Paris|245
6|Lima|New York|455
Thanks for any advice to me!
No way you can do this with auto-increment ID because IDS are not to order rows, but to identify the rows and assert it's the only row with that ID. If you want to, use a new specific column for this purpose, this way the IDs still the same and you can sort using anything as indexes.
CREATE TABLE flights (
id INTEGER AUTO_INCREMENT,
index INTEGER NOT NULL,
origin TEXT NOT NULL,
destination TEXT NOT NULL,
duration INTEGER NOT NULL,
PRIMARY KEY (id),
UNIQUE KEY unique_index (index)
);
I have the following tables:
CREATE TABLE "User" (
id integer DEFAULT nextval('"User_id_seq"'::regclass) PRIMARY KEY,
name text NOT NULL DEFAULT ''::text,
coinflips boolean[]
);
CREATE TABLE "User_coinflips_COPY" (
"nodeId" integer,
position integer,
value boolean,
id integer DEFAULT nextval('"User_coinflips_COPY_id_seq"'::regclass) PRIMARY KEY
);
I'm no looking for the SQL statement that grabs the value entry from each row in User_coinflips and inserts it as an array into the coinflips column on User.
Any help would be appreciated!
Update
Not sure if it's important but I just realized a minor mistake in my table definitions above, I replace User_coinflips with User_coinflips_COPY since that accurately describes my schema. Just for context, before it looked like this:
CREATE TABLE "User_coinflips" (
"nodeId" integer REFERENCES "User"(id) ON DELETE CASCADE,
position integer,
value boolean NOT NULL,
CONSTRAINT "User_coinflips_pkey" PRIMARY KEY ("nodeId", position)
);
You are looking for an UPDATE, rather then insert.
Use a derived table with the aggregated values to join against in the UPDATE statement:
update "User"
set conflips = t.flips
from (
select "nodeId", array_agg(value order by position) as flips
from "User_coinflips"
group by "nodeId"
) t
where t."nodeId" = "User"."nodeId";
I'm teaching myself SQL using Sqlite3, well suited for my forever-game project (Don't we all have one?) and have the following tables:
CREATE TABLE equipment_types (
row_id INTEGER PRIMARY KEY,
type TEXT NOT NULL UNIQUE);
INSERT INTO equipment_types (type) VALUES ('gear'), ('weapon');
CREATE TABLE equipment_names (
row_id INTEGER PRIMARY KEY,
name TEXT NOT NULL UNIQUE);
INSERT INTO equipment_names (name) VALUES ('club'), ('band aids');
CREATE TABLE equipment (
row_id INTEGER PRIMARY KEY,
name INTEGER NOT NULL UNIQUE REFERENCES equipment_names,
type INTEGER NOT NULL REFERENCES equipment_types);
INSERT INTO equipment (name, type) VALUES (1, 2), (2, 1);
So now we have a 'club' that is a 'weapon', and 'band aids' that are 'gear'. I now want to make a weapons table; it will have an equipment_id that references the equipment table and weapon properties like damage and range, etc. I want to constrain it to equipment that is a 'weapon' type.
But for the life of me I can't figure it out. CHECK, apparently, only allows expressions, not subqueries, and I've been trying to craft a TRIGGER that might do the job, but in short, I can't quite figure out the query and syntax, or how to check the result that as I understand it will be in the form of a table, or null.
Also, are there good online resources for learning SQL more advanced than W3School? Add them as a comment, please.
Just write a query that looks up the type belonging to the new record:
CREATE TRIGGER only_weapons
BEFORE INSERT ON weapons
FOR EACH ROW
WHEN (SELECT et.type
FROM euqipment_types AS et
JOIN equipment AS e ON e.type = et.equipment_type_id
WHERE e.row_id = NEW.equipment_id
) != 'weapon'
BEGIN
SELECT RAISE(FAIL, "not a weapon");
END;
The foreign key references should be to the primary key and to the same time. I would phrase this as:
CREATE TABLE equipment_types (
equipment_type_id INTEGER PRIMARY KEY,
type TEXT NOT NULL UNIQUE
);
INSERT INTO equipment_types (type) VALUES ('gear'), ('weapon');
CREATE TABLE equipment_names (
equipment_name_id INTEGER PRIMARY KEY,
name TEXT NOT NULL UNIQUE
);
INSERT INTO equipment_names (name) VALUES ('club'), ('band aids');
CREATE TABLE equipment (
equipment_id INTEGER PRIMARY KEY,
equipment_name_id INTEGER NOT NULL UNIQUE REFERENCES equipment_names(equipment_name_id),
equipement_type_id INTEGER NOT NULL REFERENCES equipment_types(equipement_type_id)
);
I would not use the name row_id for the primary key. That is the built-inn default, so the name is not very good. In SQLite, an integer primary key is automatically auto-incremented (see here).
I would like to do analysis of what codes appear in multiple tables under certains conditions. However I don't think the database schema suits the task very well but maybe there's something I don't know about that can help me. Here's a simplified schema:
CREATE TABLE "batchDescription" (
id INTEGER NOT NULL,
name TEXT NOT NULL UNIQUE,
PRIMARY KEY (id)
);
CREATE TABLE "simulationDetails" (
id INTEGER NOT NULL,
ko_index_id INTEGER NOT NULL,
batch_description_id INTEGER NOT NULL,
data1 REAL NOT NULL,
data2 INTEGER NOT NULL,
PRIMARY KEY (id)
FOREIGN KEY(ko_index_id) REFERENCES "koIndex" (id)
FOREIGN KEY(batch_description_id) REFERENCES "batchDescription" (id)
);
CREATE TABLE "koIndex" (
id INTEGER NOT NULL,
number_of_kos INTEGER NOT NULL,
PRIMARY KEY (id)
);
CREATE TABLE "1kos" (
ko_index_id INTEGER NOT NULL,
ko1 INTEGER NOT NULL,
PRIMARY KEY (ko_index_id)
FOREIGN KEY(ko_index_id) REFERENCES "koIndex" (id)
);
CREATE TABLE "2kos" (
ko_index_id INTEGER NOT NULL,
ko1 INTEGER NOT NULL,
ko2 INTEGER NOT NULL,
PRIMARY KEY (ko_index_id)
FOREIGN KEY(ko_index_id) REFERENCES "koIndex" (id)
);
CREATE TABLE "3kos" (
ko_index_id INTEGER NOT NULL,
ko1 INTEGER NOT NULL,
ko2 INTEGER NOT NULL,
ko3 INTEGER NOT NULL,
PRIMARY KEY (ko_index_id)
FOREIGN KEY(ko_index_id) REFERENCES "koIndex" (id)
);
This goes up to table "525kos" which has ko1 to ko525 in it - ko1 to ko525 are IDs that are primary keys in a table not shown here. I want to do an analysis of how often certain IDs are present under certain conditions. Here is a simple example to illustrate:
I would like to like to count the amount of times a certain ID (let's say 127) (in any koX column) in the "13kos" table occurs when simulationDetails.data1 not equal to 0. I would do this on a database called ko.db from the bash command line like:
for ko_idx in {1..13}; do sqlite3 ko.db "select count(ko${ko_idx}) from '13kos' where ko${ko_idx} = 127 and ko_index_id in (select ko_index_id from simulationDetails where data1 != 0);"; done
Already this is slow and inefficient but is simple compared to what I would like to do. What if I wanted to do an analysis of all the IDs in all possible columns in all "Xkos" tables and compare them to where data1 is equal and not equal to zero?
Can anybody direct me to a better way of doing this or is the schema design just not very good for this kind of analysis and I'll have to give up?
EDIT: Thought I'd add a bit of extra detailto avoid confusion. I suspect that a good way to achieve want I want would be to somehow combine all the "Xkos" tables into one temporary table and then search for certain IDs from that table. How would I combine all 525 ko tables without writing out each table name?
How would I combine all 525 ko tables without writing out each table
name?
Create a table with the same number of columns as the largest table (the table into which you merge) allowing nulls.
query the sqlite_master table using something like :-
SELECT * from sqlite_master WHERE name LIKE '%kos%' AND type = 'table'
Loop through the extracted table names building an INSERT SELECT for each table that will insert the rows from the tables into the table created in 1.
See 2. INSERT INTO table SELECT ...; especially in regard to handling missing columns.
All done, the table created in 1 will be populated accordingly.