private String pkDefinition() {
        StringBuilder pkDefinition = new StringBuilder();
        if (!CollectionUtil.isNullOrEmpty(primaryKeys)) {
            pkDefinition.append(",");
            pkDefinition.append(
                    String.format(
                            "PRIMARY KEY ( %s )",
                            primaryKeys.stream()
                                    .map(StatementUtils::quote)
                                    .collect(Collectors.joining(","))));
        }
        return pkDefinition.toString();
    }
used to generate table definition in ddl with "desc table".
inlong-sort/sort-flink/sort-flink-v1.13/sort-connectors/mysql-cdc/src/main/java/org/apache/inlong/sort/cdc/mysql/schema/MySqlTableDefinition.java