[BUGFIX] Update Cassandra driver to drop materialized views before tables

database/cassandra/cassandra.go

@@ -292,6 +292,46 @@ func (c *Cassandra) Version() (version int, dirty bool, err error) {
 }
 
 func (c *Cassandra) Drop() error {
+	// Find an Materialized View and drop them first
+	queryViews := fmt.Sprintf(`
+        SELECT view_name, base_table_name
+        FROM system_schema.views 
+        WHERE keyspace_name='%s'`,
+		c.config.KeyspaceName,
+	)
+	iterViews := c.session.Query(queryViews).Iter()
+	var viewName string
+	var baseTableName string
+	for iterViews.Scan(&viewName, &baseTableName) {
+		// ScyllaDB stores stores GSIs in the system_schema.views table as well
+		// so those have to be filtered out as scylladb is not smart enough and
+		// will throw an error if you try to drop using
+		// MATERIALIZED VIEW IF EXISTS syntax
+		if strings.HasSuffix(viewName, "_index") {
+			idxName, _ := strings.CutSuffix(viewName, "_index")
+			queryViewNotIndex := fmt.Sprintf(`
+            SELECT count(index_name)
+            FROM system_schema.indexes 
+            WHERE keyspace_name='%s' 
+                AND table_name = '%s'
+	            AND index_name = '%s'`,
+				c.config.KeyspaceName,
+				baseTableName,
+				idxName,
+			)
+			var count int
+			if err := c.session.Query(queryViewNotIndex).Scan(&count); err != nil {
+				return err
+			}
+			if count > 0 {
+				continue
+			}
+		}
+		err := c.session.Query(fmt.Sprintf(`DROP MATERIALIZED VIEW IF EXISTS %s`, viewName)).Exec()
+		if err != nil {
+			return err
+		}
+	}
 	// select all tables in current schema
 	query := fmt.Sprintf(`SELECT table_name from system_schema.tables WHERE keyspace_name='%s'`, c.config.KeyspaceName)
 	iter := c.session.Query(query).Iter()