db (schema): create virtual table for FTS + migration

rel 361

sat/memory/migration/versions/129ac51807e4_create_virtual_table_for_full_text_.py

@@ -0,0 +1,49 @@
+"""create virtual table for Full-Text Search
+
+Revision ID: 129ac51807e4
+Revises: 8974efc51d22
+Create Date: 2021-08-13 19:13:54.112538
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = '129ac51807e4'
+down_revision = '8974efc51d22'
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    queries = [
+        "CREATE VIRTUAL TABLE pubsub_items_fts "
+        "USING fts5(data, content=pubsub_items, content_rowid=id)",
+        "CREATE TRIGGER pubsub_items_fts_sync_ins AFTER INSERT ON pubsub_items BEGIN"
+        "  INSERT INTO pubsub_items_fts(rowid, data) VALUES (new.id, new.data);"
+        "END",
+        "CREATE TRIGGER pubsub_items_fts_sync_del AFTER DELETE ON pubsub_items BEGIN"
+        "  INSERT INTO pubsub_items_fts(pubsub_items_fts, rowid, data) "
+        "VALUES('delete', old.id, old.data);"
+        "END",
+        "CREATE TRIGGER pubsub_items_fts_sync_upd AFTER UPDATE ON pubsub_items BEGIN"
+        "  INSERT INTO pubsub_items_fts(pubsub_items_fts, rowid, data) VALUES"
+        "('delete', old.id, old.data);"
+        "  INSERT INTO pubsub_items_fts(rowid, data) VALUES(new.id, new.data);"
+        "END",
+        "INSERT INTO pubsub_items_fts(rowid, data) SELECT id, data from pubsub_items"
+    ]
+    for q in queries:
+        op.execute(sa.DDL(q))
+
+
+def downgrade():
+    queries = [
+        "DROP TRIGGER IF EXISTS pubsub_items_fts_sync_ins",
+        "DROP TRIGGER IF EXISTS pubsub_items_fts_sync_del",
+        "DROP TRIGGER IF EXISTS pubsub_items_fts_sync_upd",
+        "DROP TABLE IF EXISTS pubsub_items_fts",
+    ]
+    for q in queries:
+        op.execute(sa.DDL(q))