How to transfer a multidimensional array to a MySQL table (through Zeoslib)?

Question

I am using the Zeoslib library in Delphi.

I have a large multidimensional static array that I need to transfer to an empty table in a local MySQL database. How can I do this efficiently?

Just iterate through a million insert statements?

Answer 1

1. You can use MySQL syntax: INSERT INTO tab VALUES (v11,..., v1n), ..., (vm1, ..., vmn). IOW, you can collect your array rows into chunks consisting of M rows. This will seriously improve performance. (More)
2. You can offload array into text file, then use LOAD DATA INFILE statement to load text file efficiently. (More)
3. You can consider to use other 3d party libraries, like AnyDAC. Which implements Array DML feature, which is intended exactly for your task. (More)

Answer 2

Multi-dimensional array's don't translate well to MySQL.

If you're dealing with a tiny array you'll probably get things done, but it just doesn't scale. No matter what, it's going to get ugly real soon.

• For a simple 2-dimensional array, you could consider creating a column for one dimension, and use rows for the other. However, you cannot have more than 4096 columns in a table:

http://dev.mysql.com/doc/refman/4.1/en/column-count-limit.html

There is a hard limit of 4096 columns per table, but the effective maximum may be less for a given table. The exact limit depends on several interacting factors, listed in the following discussion.

Every table has a maximum row size of 65,535 bytes. This maximum applies to all storage engines, but a given engine might have additional constraints that result in a lower effective maximum row size.

• Or, you can create a row per array item, and store the index of each dimension as a primary key.But when you want to retrieve the values, you need to create a monster query.
• You either need to do:
  • multiple joins, but you can only do 61 joins in a query:

http://dev.mysql.com/doc/refman/5.0/en/joins-limits.html

The maximum number of tables that can be referenced in a single join is 61. This also applies to the number of tables that can be referenced in the definition of a view.

• • Or create a query, group by the row key, and conditionally pick the right value with the combination of a group function and a condition, something like this: sum(if(x=1,y,0))

Answer 3

I had the same problem, only in php 2D arrays. Save the dimensions of the array (x, y, z etc. length, meaning the number of values on each level). then join the whole array into ane long string, divide with a special, unique character like | or ,, and when you fetch the data you can split the sting based on the dimensions data.

If you need it, I can show you my php code, but I see you prefer delphi.

EDIT: this is an answer for your question before you edited it. Now it's kind of irrelevant.