Sqlite Increment column value based on previous row's value

问题

How do I increment a column value based on previous column value in Sqlite? I need to do this for 1000+ rows. I have data in the first row say 100. I need to increment the next 1000 rows by 2.

Row#  ColName
1       100
2       102
3       104
4       106

I tried something like this: Update Table SET ColName = (Select max(ColName ) from Table ) + 2 but this puts 102 in all columns.

回答1:

Assuming that this table has a rowid column, it is possible to count how many previous rows there are:

UPDATE MyTable
SET ColName = (SELECT MAX(ColName)
               FROM MyTable
              ) +
              (SELECT COUNT(*)
               FROM MyTable AS Previous
               WHERE Previous.rowid < MyTable.rowid
              ) * 2
WHERE ColName IS NULL

来源：https://stackoverflow.com/questions/23834181/sqlite-increment-column-value-based-on-previous-rows-value