How to SELECT the last 10 rows of an SQL table whi

Question

I have an MySQL table with 25000 rows.

This is an imported CSV file so I want to look at the last ten rows to make sure it imported everything.

However, since there is no ID column, I can't say:

SELECT * FROM big_table ORDER BY id DESC

What SQL statement would show me the last 10 rows of this table?

The structure of the table is simply this:

columns are: A, B, C, D, ..., AA, AB, AC, ... (like Excel)
all fields are of type TEXT

Answer 1

SQL tables have no implicit ordering, the order has to come from the data. Perhaps you should add a field to your table (e.g. an int counter) and re-import the data.

However that will only give the order of the import and not the data. If your data has no ordering you have to find out how to add it.

EDIT: you say

...to make sure it imported everything.

What's wrong with using row count?

Answer 2

executing a count(*) query on big data is expensive. i think using "SELECT * FROM table ORDER BY id DESC LIMIT n" where n is your number of rows per page is better and lighter

Answer 3

All the answers here are better, but just in case... There is a way of getting 10 last added records. (thou this is quite unreliable :) ) still you can do something like

SELECT * FROM table LIMIT 10 OFFSET N-10

N - should be the total amount of rows in the table (SELECT count(*) FROM table). You can put it in a single query using prepared queries but I'll not get into that.

Answer 4

you can with code select 10 row from end of table. select * from (SELECT * FROM table1 order by id desc LIMIT 10) as table2 order by id"

Answer 5

If you know how many rows to expect, I would create a separate temporary table in your database of the expected structure, append into that, then check the count... Once you are good with that, then you can massage that data before appending it into your final production table.

Answer 6

A low-tech approach: Doing this with SQL might be overkill. According to your question you just need to do a one-time verification of the import.

Why not just do: SELECT * FROM ImportTable

and then scroll to the bottom of the results grid and visually verify the "last" few lines.