diff --git a/the_works/models.py b/the_works/models.py
index abb8405..59cd9a6 100644
--- a/the_works/models.py
+++ b/the_works/models.py
@@ -29,7 +29,7 @@ class Genre(Base):
   __tablename__ = 'Genre'
 
   ID: Mapped[int] = mapped_column(primary_key=True)
-  Genre: Mapped[str]
+  Genre: Mapped[str] = mapped_column(unique=True)
 
   texte: Mapped[List['Text_Genre']] = relationship(back_populates='genre')
   werke: Mapped[List['Werk_Genre']] = relationship(back_populates='genre')
@@ -39,7 +39,7 @@ class Herausgeber(Base):
   __tablename__ = 'Herausgeber'
 
   ID: Mapped[int] = mapped_column(primary_key=True)
-  Name: Mapped[str]
+  Name: Mapped[str] = mapped_column(unique=True)
 
   werke: Mapped[List['Werk_Herausgeber']] = relationship(back_populates='herausgeber')
 
@@ -48,7 +48,7 @@ class Pseudonym(Base):
   __tablename__ = 'Pseudonym'
 
   ID: Mapped[int] = mapped_column(primary_key=True)
-  Pseudonym: Mapped[str]
+  Pseudonym: Mapped[str] = mapped_column(unique=True)
 
   veroeffentlichung: Mapped[List['Veroeffentlichung']] = relationship(back_populates='pseudonym')
 
@@ -57,7 +57,7 @@ class Sprache(Base):
   __tablename__ = 'Sprache'
 
   ID: Mapped[int] = mapped_column(primary_key=True)
-  Sprache: Mapped[str]
+  Sprache: Mapped[str] = mapped_column(unique=True)
 
   text: Mapped[List['Text']] = relationship(back_populates='sprache')
 
@@ -66,7 +66,7 @@ class Textform(Base):
   __tablename__ = 'Textform'
 
   ID: Mapped[int] = mapped_column(primary_key=True)
-  Textform: Mapped[str]
+  Textform: Mapped[str] = mapped_column(unique=True)
 
   text: Mapped[List['Text']] = relationship(back_populates='textform')
 
@@ -97,7 +97,7 @@ class Verlag(Base):
   __tablename__ = 'Verlag'
 
   ID: Mapped[int] = mapped_column(primary_key=True)
-  Verlag: Mapped[str]
+  Verlag: Mapped[str] = mapped_column(unique=True)
 
   reihe: Mapped[List['Reihe']] = relationship(back_populates='verlag')
   werk: Mapped[List['Werk']] = relationship(back_populates='verlag')
@@ -107,7 +107,7 @@ class Werksform(Base):
   __tablename__ = 'Werksform'
 
   ID: Mapped[int] = mapped_column(primary_key=True)
-  Werksform: Mapped[str]
+  Werksform: Mapped[str] = mapped_column(unique=True)
 
   werk: Mapped[List['Werk']] = relationship(back_populates='werksform')