Thanks Phil - it's not quite a solution but it's a lead. So the following works.

TRUNCATE TABLE profiler_current.email_profiler

go

INSERT INTO

profiler_current.email_profiler( email_address)

SELECT

gc.`E-mail 2 - Value`

FROM

src_google_current.google_contacts gc

UNION

SELECT

gc.`E-mail 3 - Value`

FROM

src_google_current.google_contacts gc

UNION

SELECT

gc.`E-mail 4 - Value`

FROM

src_google_current.google_contacts gc

UNION

SELECT

Email

FROM

src_sfdc_current.sfdc_contacts sc

UNION

SELECT

Private_Email__c

FROM

src_sfdc_current.sfdc_contacts sc

go

(though I'm not entirely sure why). The problem this then gives is that the script no longer works if I run it native in mysql. issuing the command 'delimiter go' at the start of the script helps, but, this falls over if the script has the string 'go' (which occurs twice for example in '......FROM

src_google_current.google_contacts gc......).

So there is a bit more to it but maybe your input and these comments will trigger further comment.

Incidentally after opening the connection but before issuing the main sql I am issuing

set sql_mode='STRICT_TRANS_TABLES,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION,ANSI_QUOTES';