SQL Server & Visual Studio - Insert Data in tables doesn't work - sql-server

Question

I want to insert my tables from my SQL Server Management Studio code with data via Visual Studio.
But it doesn't work. The ID of my table doesn't get a value automatically (but I have command it with identity(1,1)) and an error appears that it stands in conflict with a foreign-key-constraint.
create table [ProduktZahlungFENutzer]
(
ID int PRIMARY KEY IDENTITY(1,1) NOT NULL,
Endpreis decimal(3, 2)
);
CREATE TABLE [FHAngehörige]
(
FHAngehörigeID INT NOT NULL IDENTITY(1,1)
PRIMARY KEY Constraint fhA_feN
REFERENCES FENutzer(FENutzerID),
Name VARCHAR(50) NOT NULL,
Fachbereich INT NOT NULL,
Email VARCHAR(50) NOT NULL UNIQUE
)
CREATE TABLE [FENutzer]
(
FENutzerID INT IDENTITY(1,1) NOT NULL
PRIMARY KEY constraint t_nutzer
references ProduktZahlungFENutzer(ID),
Aktiv INT NOT NULL,
LetzterLogin datetime NOT NULL DEFAULT GETDATE(),
BENutzerID int NOT NULL
constraint FENutzer_BENutzer
foreign key references BENutzer(BENutzerID),
auth_id int not null
constraint FENutzer_auth
foreign key references auth2(id)
)
Please help

Answer 1

You have established a reference
FHAngehörigeID INT NOT NULL IDENTITY(1,1) PRIMARY KEY Constraint fhA_feN
REFERENCES FENutzer(FENutzerID),
This means that you need a record in your table FENutzer.FENutzerID that match FHAngehörigeID, in this case you cannot use IDENTITY

Answer 2

Your construction makes no sense - this way, you're creating two tables that depend on each other, at the primary key level - so you would have to have an existing entry in FENutzer in order to insert a new row into FHAngehörige, and this at the same time is only possible if you already have an existing row in FHAngehörige to insert the row in FEnutzer.....
You need to clean this up:
both tables need a primary key and the int identity(1,1) is a very good choice
one of the tables must reference the other, but with a normal foreign key attribute - not on the primary key.....
Since you've not given any indication as to which of the tables is the "main" table and which the "child/auxiliary" table, I'm just picking one over the other - so your table structure should be something like:
CREATE TABLE dbo.FHAngehoerige
(
FHAngehoerigeID INT NOT NULL IDENTITY(1,1)
CONSTRAINT PK_FHAngehoerige PRIMARY KEY CLUSTERED,
Name VARCHAR(50) NOT NULL,
Fachbereich INT NOT NULL,
Email VARCHAR(50) NOT NULL UNIQUE
)
CREATE TABLE dbo.FENutzer
(
-- define the PK for the table
FENutzerID INT IDENTITY(1,1) NOT NULL
CONSTRAINT PK_FENutzer PRIMARY KEY CLUSTERED,
-- define the **foreign key** to the main table
FHAngehoerigeID INT NOT NULL
CONSTRAINT FK_FENutzer_FHAngehoerige
FOREIGN KEY REFERENCES dbo.FHAngehoerige(FHAngehoerigeID),
Aktiv INT NOT NULL,
LetzterLogin datetime NOT NULL DEFAULT GETDATE(),
BENutzerID int NOT NULL
constraint FENutzer_BENutzer
foreign key references BENutzer(BENutzerID),
auth_id int not null
constraint FENutzer_auth
foreign key references auth2(id)
)
Also: I would strongly recommend (from my own personal, bad experience) to AVOID any special characters like umlauts or accents or anything like that in table and column names.....