Use this query to mass create job numbers:

Insert Into [Job] ([DBId], [Id], [Number], [ClientId], [JobTypeId], [DivisionId], [Description], [Actif], [Archive], [JobServiceTRRestriction], [StartDate], [EndDate], [Chargeable], [Status], [TRLockType], [FileHolderEmployeeId], [ReferenceYear], [SupplierBudgetAmount], [JobCategoryId], [StrategyId])
Select [Client].[DBId] as [ResDBId],
ROW_NUMBER() OVER(ORDER BY [Client].[Id] ASC) + 13858 AS [ResId],
left(case when [Company].[Name] Is Null then [Person].[Name] else [Company].[Name] end,61) + ' - Liquidation' as [ResNumber],
[Client].[Id] as [ResClientId],
0 as [ResJobTypeId],
0 as [ResDivisionId],
'' as [ResDescription],
1 as [ResActif],
0 as [ResArchive],
1 as [JobServiceTRRestriction],
'30/12/1899' as [StartDate],
'30/12/1899' as [EndDate],
0 as [Chargeable],
0 as [Status],
0 as [TRLockType],
0 as [FileHolderEmployeeId],
'30/12/1899' as [ReferenceYear],
0 as [SupplierBudgetAmount],
0 as [JobCategoryId],
0 as [StrategyId]
from (([Client] LEFT JOIN [Company]
ON ([Client].[CompanyId] = [Company].[Id] and [Client].[DBId] = [Company].[DBId]))
LEFT JOIN [Person]
ON ([Client].[PersonId] = [Person].[Id] and [Client].[DBId] = [Person].[DBId]))
where [Client].[DBId] = XXX