Update Row With Foreign Key Relationships

Hi,

I have 2 tables Publication and Advertisment_Codes. I want to update the publication_code in both tables where country_id=1 and publication_code='A'. However, it gives me an error because of foreign key relationship. I tried first updating in Advertisment_Codes and then in Publication table but it didn't work. I tried the other way round but also it didn't work.
How can I update the publication code?
Thanks


CREATE TABLE [dbo].[Advertisment_Codes](
[Advertising_Code] [nvarchar](20) NOT NULL,
[Country_id] [int] NOT NULL CONSTRAINT [DF_Advertisment_Codes_Country_id] DEFAULT ((0)),
[Publication_code] [nvarchar](20) NULL,
[Advert_type] [nchar](1) NULL,
[Date_Entered] [datetime] NULL,
[User_Id_Ent] [int] NULL CONSTRAINT [DF_Advertisment_Codes_User_Id_Ent] DEFAULT ((0)),
[Date_Updated] [datetime] NULL,
[User_Id_Upd] [int] NULL CONSTRAINT [DF_Advertisment_Codes_User_Id_Upd] DEFAULT ((0)),
[Default_Code] [bit] NULL CONSTRAINT [DF_Advertisment_Codes_Default_Code] DEFAULT ((0)),
[Active] [bit] NULL CONSTRAINT [DF_Advertisment_Codes_Active] DEFAULT ((0)),
CONSTRAINT [PK_Advertisment_Codes_1] PRIMARY KEY CLUSTERED
(
[Advertising_Code] ASC,
[Country_id] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]

GO
ALTER TABLE [dbo].[Advertisment_Codes] WITH CHECK ADD CONSTRAINT [FK_Advertisment_Codes_Countries] FOREIGN KEY([Country_id])
REFERENCES [dbo].[Countries] ([Country_id])
GO
ALTER TABLE [dbo].[Advertisment_Codes] CHECK CONSTRAINT [FK_Advertisment_Codes_Countries]
GO
ALTER TABLE [dbo].[Advertisment_Codes] WITH CHECK ADD CONSTRAINT [FK_Advertisment_Codes_Publications] FOREIGN KEY([Country_id], [Publication_code])
REFERENCES [dbo].[Publications] ([Country_id], [Publication_code])
GO
ALTER TABLE [dbo].[Advertisment_Codes] CHECK CONSTRAINT [FK_Advertisment_Codes_Publications]

CREATE TABLE [dbo].[Publications](
[Country_id] [int] NOT NULL,
[Publication_code] [nvarchar](20) NOT NULL,
[Publication_name] [nvarchar](50) NOT NULL,
[Media_type] [int] NOT NULL CONSTRAINT [DF_Puclications_Media_type] DEFAULT ((0)),
[Date_Entered] [datetime] NULL,
[User_Id_Ent] [int] NULL CONSTRAINT [DF_Publications_User_Id_Ent] DEFAULT ((0)),
[Date_Updated] [datetime] NULL,
[User_Id_Upd] [int] NULL CONSTRAINT [DF_Publications_User_Id_Upd] DEFAULT ((0)),
CONSTRAINT [PK_Puclications] PRIMARY KEY CLUSTERED
(
[Country_id] ASC,
[Publication_code] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]

GO
ALTER TABLE [dbo].[Publications] WITH CHECK ADD CONSTRAINT [FK_Publications_Countries] FOREIGN KEY([Country_id])
REFERENCES [dbo].[Countries] ([Country_id])
GO
ALTER TABLE [dbo].[Publications] CHECK CONSTRAINT [FK_Publications_Countries]

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