Function insert_schema_backup_row 

pub fn insert_schema_backup_row(
    audit: &Option<Arc<AuditDb>>,
    ts: &str,
    connection_name: &str,
    database: Option<&str>,
    table: &str,
    schema_sql: Option<&str>,
) -> Result<i64>

Insert a schema-only backup row (used by the MySQL and SQLite paths).