[add]: balance to loan table

app/models/loan.py

@@ -35,6 +35,7 @@ class Loan(db.Model):
     continuous_fee = db.Column(db.Float, default=0)
     upfront_fee = db.Column(db.Float, nullable=True, default=0.0)
     repayment_amount = db.Column(db.Float, nullable=True, default=0.0)
+    balance = db.Column(db.Float, nullable=True, default=0.0)
     installment_amount = db.Column(db.Float, nullable=True, default=0.0)
     status = db.Column(db.String(20), default='pending')
     tenor = db.Column(db.Integer, nullable=True)
@@ -112,6 +113,7 @@ class Loan(db.Model):
             current_loan_amount = initial_loan_amount,
             upfront_fee = upfront_fee,
             repayment_amount = repayment_amount,
+            balance = repayment_amount,
             installment_amount = installment_amount,
             due_date=due_date,
             tenor = tenor,

migrations/versions/48c62b4da905_.py

@@ -0,0 +1,32 @@
+"""empty message
+
+Revision ID: 48c62b4da905
+Revises: 7a0caf83d5be
+Create Date: 2025-06-23 11:08:22.928700
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = '48c62b4da905'
+down_revision = '7a0caf83d5be'
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    with op.batch_alter_table('loans', schema=None) as batch_op:
+        batch_op.add_column(sa.Column('balance', sa.Float(), nullable=True))
+
+    # ### end Alembic commands ###
+
+
+def downgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    with op.batch_alter_table('loans', schema=None) as batch_op:
+        batch_op.drop_column('balance')
+
+    # ### end Alembic commands ###