Build, test, and debug regular expressions
Matches SQL Server T-SQL scripts that conditionally add a DEFAULT ((0)) constraint to a table column, first checking the sys.objects catalog view for an existing default constraint (type = 'D'). It captures the schema name, table name, and target column name from the bracketed identifiers. Useful for parsing SSMS-generated DDL scripts, extracting constraint metadata, or validating migration/deployment scripts.