samedi 19 décembre 2015

Sqlite query - How I can select a predecessor?

I have this table below:

ID    name    Last
0     Joe     Doe
1     Hut     Nob
2     Lis     Hug
3     Edy     mur

I use this query to select an ID:

SELECT name FROM myDatabase WHERE ID = 2

In this case the query returns me the string Lis, now, How I can select the predecessor value?

Simple, the predecessor from 2 is 1, so I need only to do WHERE ID < 2 or WHERE ID = 2 - 1.

But this method have a problem! Lets suppose that I delete that row (ID = 1), the query will return null, because that ID not exists.

So, in this example, how I can select the predecessor from ID 2 and return ID 0? (ID 1 is gone)

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