How this multiple join works
SELECT COMPANY.companyname,email,COMPANY.website,COMPANY.country as country,
COMPANY.category as category,COMPANY.urlorcatalog as Source,
COMPANY.contactperson as Contact,COMPANY.telphone as Tel,COMPANY.mobile as Mobile,
COMPANY.fax,COMPANY.region as Region,COMPANY.status as status,
USR.name as Useir,USR1.name as Updatedby,COMPANY.date,
COMPANY.active,EMAIL.DataId as ID,EMAIL.ID
FROM dbo.companyinfo COMPANY
INNER JOIN dbo.emailinfo EMAIL ON COMPANY.dataID = EMAIL.DataID
LEFT OUTER JOIN dbo.userinfo USR ON COMPANY.userid=USR.ID
LEFT OUTER JOIN dbo.userinfo USR1 ON COMPANY.lastupdatedby=USR1.ID