Create table by different columns inserts - mysql

Question

I have a source(web pages) that have common data and uncommon data that which I need to store in one table.
The data can look like this:
model: xyz, attr_1: xyz, attr_2: xyz
model: xyz, attr_3: xyz, attr_4: xyz
model: xyz, attr_1: xyz, attr_4: xyz
model: xyz, attr_1: xyz, attr_5: xyz
model: xyz, attr_15: xyz, attr_20: xyz
This data will generate this DML:
insert into table (model, attr_1, attr_2)values('xyz','xyz','xyz');
insert into table (model, attr_3, attr_4)values('xyz','xyz','xyz');
insert into table (model, attr_1, attr_4)values('xyz','xyz','xyz');
insert into table (model, attr_1, attr_5)values('xyz','xyz','xyz');
insert into table (model, attr_15, attr_20)values('xyz','xyz','xyz');
My problem is that I can't define the table before the insert commands so I can't know the columns and in every new insert I may discover new columns. I can't get all the insert commands before the actual insert. The only thing I think of is to insert every row to different table (using create table as insert into) and then use UNION ALL to create the final table. But this sound not so good idea.
EDIT I don't looking for normalized table.
The end result should be(as for the example):
table_name
id int
model varchar
attr_1 varchar
attr_2 varchar
attr_3 varchar
attr_4 varchar
attr_5 varchar
attr_15 varchar
attr_20 varchar

Answer 1

There's a really simple solution to this. You need to change your table:
table: model
modelName attribute value
xyz 1 xyz
xyz 2 xyz
Then when you do the INSERT, you would do:
INSERT INTO `model` (`modelName`, `attribute`, `value`) VALUES ('xyz', 1, 'xyz')
This is a normalized table structure that allows for n amount of attributes.

Answer 2

If you use an Array to get your data then you could use PHP's implode(', ', $array). But, you may not be using PHP. If that's the case you could always just concatenate what you're INSERTing with ,.

Answer 3

Right solution is to normalize your schema.
Create 2 tables: master table for main model - pretty much what you have now, but without attributes, and slave table to keep attributes. Something like this:
CREATE TABLE master (
master_id INTEGER PRIMARY KEY AUTOINCREMENT,
model VARCHAR(50)
);
CREATE TABLE attrs (
attr_id INTEGER PRIMARY KEY AUTOINCREMENT,
master_id INTEGER NOT NULL,
attr_name VARCHAR(20)
);
This schema is rather compact and has some important properties. For example, it allows you to keep arbitrary number of attributes associated with given model - it could be 0, or it could be 1000.
To insert data, you will need insert in master table first, and then to attrs table.
To retrieve data, use simple join like this:
SELECT m.model,
a.attr_name
FROM master m
JOIN attrs a ON m.model_id = a.model_id
WHERE ...