SQLite 3.8

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CREATE TABLE items
(
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    item TEXT
);
CREATE TABLE tags
(
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    tag TEXT
);
CREATE TABLE categorys
(
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    category TEXT
);
CREATE TABLE itemTagBridge
(
    itemId INTEGER,
    tagId INTEGER, 
    PRIMARY KEY (itemId, tagId),
    FOREIGN KEY (itemID) REFERENCES items (id),
    FOREIGN KEY (tagId)  REFERENCES tags (id)
);
CREATE TABLE tagCategoryBridge
(
    tagId INTEGER,
    categoryId INTEGER,  
    PRIMARY KEY (tagId, categoryId),
    FOREIGN KEY (tagId) REFERENCES tags (id),
    FOREIGN KEY (categoryId) REFERENCES categorys (id)
);
INSERT INTO items (item)
VALUES ('Hello World!'), ('Goodbye World');


INSERT INTO categorys (category) VALUES ('keyword'), ('title');
INSERT INTO tags (tag)
VALUES ('positivity'), ('hello'), ('negativity'), ('goodbye'), ('helloWorld'), ('goodByeWorld');
INSERT INTO itemTagBridge
VALUES(1, 1), (1, 2), (1, 5), (2, 3), (2, 4), (2, 6);
INSERT INTO tagCategoryBridge
VALUES (1, 1), (2, 1), (3, 1), (4, 1), (5, 2), (6, 2);
SELECT * FROM items;


id
item


1
Hello World!

2
Goodbye World


SELECT * FROM tags;


id
tag


1
positivity

2
hello

3
negativity

4
goodbye

5
helloWorld

6
goodByeWorld


SELECT * FROM categorys;


id
category


1
keyword

2
title


SELECT * FROM itemTagBridge;


itemId
tagId


1
1

1
2

1
5

2
3

2
4

2
6


SELECT * FROM tagCategoryBridge;


tagId
categoryId


1
1

2
1

3
1

4
1

5
2

6
2
id	tag
1	positivity
2	hello
3	negativity
4	goodbye
5	helloWorld
6	goodByeWorld