Return an error from Schema.Add when the table spec is nil (#608)

Ran into this error when trying to process a SQL file introducing a view, and
it was hard to chase down.

Co-authored-by: Kyle Conroy <kyle@conroy.org>

Author: alecbz

internal/mysql/parse.go

@@ -123,8 +123,7 @@ func (pGen PackageGenerator) parseQueryString(tree sqlparser.Statement, query st
 		}
 		parsedQuery = delete
 	case *sqlparser.DDL:
-		pGen.Schema.Add(tree)
-		return nil, nil
+		return nil, pGen.Schema.Add(tree)
 	default:
 		// panic("Unsupported SQL statement type")
 		return nil, nil

internal/mysql/schema.go

@@ -55,15 +55,16 @@ func tableColReferences(col *sqlparser.ColName, defaultTable string, tableAliasM
 }
 
 // Add add a MySQL table definition to the schema map
-func (s *Schema) Add(ddl *sqlparser.DDL) {
+func (s *Schema) Add(ddl *sqlparser.DDL) error {
 	switch ddl.Action {
 	case "create":
 		name := ddl.Table.Name.String()
 		if ddl.TableSpec == nil {
-			panic(fmt.Sprintf("failed to parse table \"%s\" schema.", name))
+			return fmt.Errorf("failed to parse table \"%s\" schema", name)
 		}
 		s.tables[name] = ddl.TableSpec.Columns
 	}
+	return nil
 }
 
 func (s *Schema) schemaLookup(table string, col string) (*Column, error) {