SQLite and multiple insert clean - sqlite

Question

I would like to populate a freshly created Table in a SQLite DB.
In this table, some keys are references to other tables and I'd like not to hard-code these references
-> I'm currently using a "mapping" table in order to fetch ids using names (~ constants emulation)
The problem is: this solution works but is very verbose
Minimal working example: (storing dictionary words, using foreign keys to a category table)
-- Tables creation
CREATE TABLE categories(
id INTEGER PRIMARY KEY,
name TEXT
);
CREATE TABLE words(
id INTEGER PRIMARY KEY,
id_category INTEGER NOT NULL,
name TEXT,
FOREIGN KEY(id_category) REFERENCES categories(id)
);
CREATE TABLE CONSTANTS(
name TEXT PRIMARY KEY,
value INTEGER NOT NULL
);
INSERT INTO categories(name) VALUES("noun");
INSERT INTO CONSTANTS(name, value) VALUES("category_noun", last_insert_rowid());
INSERT INTO categories(name) VALUES("abreviation");
INSERT INTO CONSTANTS(name, value) VALUES("category_abreviation", last_insert_rowid());
INSERT INTO categories(name) VALUES("character");
INSERT INTO CONSTANTS(name, value) VALUES("category_character", last_insert_rowid());
And now, the core of the problem: too much verbose.
In this example is only one foreign key, a few insert to illustrate the problem
INSERT INTO words(id_category, name) VALUES
((SELECT value FROM CONSTANTS WHERE name = "category_noun"),
"hello"),
((SELECT value FROM CONSTANTS WHERE name = "category_abreviation"),
"SO"),
((SELECT value FROM CONSTANTS WHERE name = "category_abreviation"),
"user"),
((SELECT value FROM CONSTANTS WHERE name = "category_character"),
"!")
;
I would like to have something looking like this pseudo-sqlite code:
-- same table creations as before
INSERT INTO words(id_category, name) VALUES
-- Fetch constants once
CAT_NOUM = SELECT value FROM CONSTANTS WHERE name = "category_noum"),
CAT_ABREV = SELECT value FROM CONSTANTS WHERE name = "category_abreviation"),
CAT_CHAR = SELECT value FROM CONSTANTS WHERE name = "category_abreviation")
)
-- Fill the table, using constants
(CAT_NOUM, "Hello"),
(CAT_ABREV, "SO"),
(CAT_NOUM, "user"),
(CAT_CHAR, "SO"),
...
;
I'm wondering if
There is already a SQLite solution to this problem
I should use something like sed to replace a hard-coded string like __SED__CAT_NOUM with its greped value in the SQLite script
Doing this stuff programmatically would be the right way

Answer 1

It is better to use INSERT...SELECT with UNION ALL instead of INSERT...VALUES:
INSERT INTO words(id_category, name)
SELECT value, 'hello' FROM CONSTANTS WHERE name = 'category_noun' UNION ALL
SELECT value, 'SO' FROM CONSTANTS WHERE name = 'category_abreviation' UNION ALL
SELECT value, 'user' FROM CONSTANTS WHERE name = 'category_abreviation' UNION ALL
SELECT value, '!' FROM CONSTANTS WHERE name = 'category_character';
See the demo.
Or use Row Values to join to CONSTANTS:
INSERT INTO words(id_category, name)
SELECT c.value, t.column2
FROM CONSTANTS C INNER JOIN (
VALUES ('category_noun', 'hello'),
('category_abreviation', 'SO'),
('category_abreviation', 'user'),
('category_character', '!')
) t ON t.column1 = c.name;
See the demo.
Results:
SELECT * FROM words;
| id | id_category | name |
| --- | ----------- | ----- |
| 1 | 1 | hello |
| 2 | 2 | SO |
| 3 | 2 | user |
| 4 | 3 | ! |