Question

Anybody know what does it mean base property in @IndexColumn annotation?
And what a different between base=0 and base=1

Answer 1

Judging from IndexColumn API base property is index in DB start from base which default to 0.

It means what is the starting point in your database for indexing. Java arrays are 0-based, but in database you might have 1..n values, where base would be 1 then. eg.:

@IndexColumn(base = 1)               @IndexColumn(base = 0)

DB     Java                          DB     Java
1      0      <---  position  -->    0      0
2      1                             1      1
3      2                             2      2