Make loan.patron_id and hold.patron_id fields non-nullable.

alembic/versions/20241119_58b0ae7f5b67_make_loan_patron_id_and_hold_patron_id_.py

@@ -0,0 +1,43 @@
+"""Make Loan.patron_id and Hold.patron_id non-nullable.
+
+Revision ID: 58b0ae7f5b67
+Revises: 272da5f400de
+Create Date: 2024-11-19 18:04:24.182444+00:00
+
+"""
+
+from alembic import op
+
+# revision identifiers, used by Alembic.
+revision = "58b0ae7f5b67"
+down_revision = "272da5f400de"
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    op.alter_column(
+        table_name="loans",
+        column_name="patron_id",
+        nullable=False,
+    )
+
+    op.alter_column(
+        table_name="holds",
+        column_name="patron_id",
+        nullable=False,
+    )
+
+
+def downgrade() -> None:
+    op.alter_column(
+        table_name="loans",
+        column_name="patron_id",
+        nullable=True,
+    )
+
+    op.alter_column(
+        table_name="holds",
+        column_name="patron_id",
+        nullable=True,
+    )

src/palace/manager/sqlalchemy/model/patron.py

@@ -512,7 +512,7 @@ class Loan(Base, LoanAndHoldMixin):
     __tablename__ = "loans"
     id = Column(Integer, primary_key=True)
 
-    patron_id = Column(Integer, ForeignKey("patrons.id"), index=True)
+    patron_id = Column(Integer, ForeignKey("patrons.id"), index=True, nullable=False)
     patron: Mapped[Patron] = relationship("Patron", back_populates="loans")
 
     # A Loan is always associated with a LicensePool.
@@ -562,7 +562,7 @@ class Hold(Base, LoanAndHoldMixin):
 
     __tablename__ = "holds"
     id = Column(Integer, primary_key=True)
-    patron_id = Column(Integer, ForeignKey("patrons.id"), index=True)
+    patron_id = Column(Integer, ForeignKey("patrons.id"), index=True, nullable=False)
     license_pool_id = Column(Integer, ForeignKey("licensepools.id"), index=True)
     license_pool: Mapped[LicensePool] = relationship(
         "LicensePool", back_populates="holds"