Total newbie here, regarding sqlite, so don't flame too hard :)
I have a table:
index name length L breadth B height H
1 M-1234 10 5 2
2 M-2345 20 10 3
3 ....
How do I put some tabular data (let' say ten x,y values) corresponding to index 1, then another table to index 2, and then another, etc. In short, so that I have a table of x and y values that is "connected" to first row, then another that is connected to second row.
I'm reading some tutorials on sqlite3 (which I'm using), but am havin开发者_如何转开发g trouble finding this. If anyone knows a good newbie tutorial or a book dealing with sqlite3 (CLI) I'm all ears for that too :)
You are just looking for information on join
s and the concept of foreign key
, that although SQLite3 doesn't enforce, is what you need. You can go without it, anyway.
In your situation you can either add two "columns" to your table, being one x
and another y
, or create a new table with 3 "columns": foreign_index
, x
and y
. Which one to use depends on what you are trying to accomplish, performance and maintainability.
If you go the linked table route, you'd end up with two tables, like this:
MyTable
index name length L breadth B height H
1 M-1234 10 5 2
2 M-2345 20 10 3
3 ....
XandY
foreign_index x y
1 12 9
2 8 7
3 ...
When you want the x
and y
values of your element, you just use something like SELECT x, y FROM XandY WHERE foreign_index = $idx;
To get all the related attributes, you just do a JOIN
:
SELECT index, name, length, breadth, height, x, y FROM MyTable INNER JOIN XandY ON MyTable.index = XandY.foreign_index;
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