How can i get original value of a custom field from bd ?

[Deleted user]

I need to retrieve all the previous values of a custom field from certain ticket/issue using sql from jira's database. Using the tables "changeitem" and "changegroup" I am able to obtain all the values of the custom field from a certain ticket whenever it changes, but i cant get the initial value of the customfield. The "jiraissues" table doesnt have the initial value either

[Nic Brough -Adaptavist-]

The changeitem table contains "old value" and "new value".  To get the original value on create, read the earliest change of the field.