Create subscriptions table in discovery DB (#4254)

* Migration

* Add indexes

* Model

* Add server default for timestamp in model

* Linter

* isort

* black

* Typo

discovery-provider/alembic/versions/03dbd1b775c5_create_subscriptions_table.py

@@ -0,0 +1,45 @@
+"""create_subscriptions_table
+
+Revision ID: 03dbd1b775c5
+Revises: 42d5afb85d42
+Create Date: 2022-11-02 03:16:19.526141
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = '03dbd1b775c5'
+down_revision = '42d5afb85d42'
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    op.create_table(
+        "subscriptions",
+        sa.Column("blockhash", sa.String()),
+        sa.Column("blocknumber", sa.Integer(), index=True),
+        sa.Column("subscriber_id", sa.Integer(), nullable=False),
+        sa.Column("user_id", sa.Integer(), nullable=False, index=True),
+        sa.Column("is_current", sa.Boolean(), nullable=False),
+        sa.Column("is_delete", sa.Boolean(), nullable=False),
+        sa.Column("created_at", sa.DateTime(), nullable=False, server_default=sa.func.current_timestamp()),
+        sa.Column("txhash", sa.String(), nullable=False, server_default=""),
+        sa.ForeignKeyConstraint(
+            ["blockhash"],
+            ["blocks.blockhash"],
+        ),
+        sa.ForeignKeyConstraint(
+            ["blocknumber"],
+            ["blocks.number"],
+        ),
+        sa.PrimaryKeyConstraint(
+            "subscriber_id", "user_id", "is_current", "txhash"
+        ),
+    )
+
+
+def downgrade():
+    op.drop_table("subscriptions")

discovery-provider/src/models/social/subscription.py

@@ -0,0 +1,31 @@
+from sqlalchemy import Boolean, Column, DateTime, ForeignKey, Integer, String, text
+from sqlalchemy.orm import relationship
+from src.models.base import Base
+from src.models.model_utils import RepresentableMixin
+
+
+class Subscription(Base, RepresentableMixin):
+    __tablename__ = "subscriptions"
+
+    blockhash = Column(ForeignKey("blocks.blockhash"))  # type: ignore
+    blocknumber = Column(ForeignKey("blocks.number"), index=True)  # type: ignore
+    subscriber_id = Column(Integer, primary_key=True, nullable=False)
+    user_id = Column(Integer, primary_key=True, nullable=False, index=True)
+    is_current = Column(Boolean, primary_key=True, nullable=False)
+    is_delete = Column(Boolean, nullable=False)
+    created_at = Column(
+        DateTime, nullable=False, server_default=text("CURRENT_TIMESTAMP")
+    )
+    txhash = Column(
+        String,
+        primary_key=True,
+        nullable=False,
+        server_default=text("''::character varying"),
+    )
+
+    block = relationship(  # type: ignore
+        "Block", primaryjoin="Subscription.blockhash == Block.blockhash"
+    )
+    block1 = relationship(  # type: ignore
+        "Block", primaryjoin="Subscription.blocknumber == Block.number"
+    )