@Override
    public String toSqlExpression() {
        Object[][] value = getValue();
        if (value == null || value.length == 0) {
            return ClickHouseValues.EMPTY_ARRAY_EXPR;
        }

        StringBuilder builder = new StringBuilder();
        for (Object[] v : value) {
            if (v == null || v.length == 0) {
                builder.append(ClickHouseValues.EMPTY_ARRAY_EXPR);
            } else {
                builder.append('[');
                for (Object o : v) {
                    builder.append(ClickHouseValues.convertToSqlExpression(o)).append(',');
                }
                builder.setLength(builder.length() - 1);
                builder.append(']');
            }
            builder.append(',');
        }
        builder.setLength(builder.length() - 1);
        return builder.toString();
    }
Gets immutable list of nested columns.

@return immutable list of columns
clickhouse-data/src/main/java/com/clickhouse/data/value/ClickHouseNestedValue.java