New data types

optional

Nullable values are represented as std::optional if you are using C++17 or later, sqlpp::compat::optional otherwise.

string_view

Text results are represented as std::string_view if you are using C++17 or later, sqlpp::compat::string_view otherwise.

span<uint8_t>

Blob results are represented as std::span<uint8_t> if you are using C++20 or later, sqlpp::compat::span<uint8_t> otherwise.

Result values

Result rows are represented as structs with the respective columns represented as data members. In version 1.0, these data members used to have a type that wrapped the actual data and provided conversion operators and functions to check for NULL.

Now data members have the correct data type, e.g. int64_t or optional<string_view>.

No read-only columns

Version 1.0 had the concept of read-only columns, e.g. you could not modify a column with auto-increment values.

This concept has been removed. In most cases, you will still not want to modify columns with auto-increment values, but you can do it now, if you want to.

IS DISCTINCT FROM

Version 1.0 used to have is_equal_to_or_null which translated to either = or IS NULL. While useful, this did not work with parameters.

The library now offers is_distinct_from and is_not_distinct_from which safely compares with actual values and NULL.

Selecting aggregate functions

In version 1.0, many functions automatically came with a name. This was convenient for selecting, but also rather unspecific, e.g. select(max(tab.price)).from(tab).unconditionally() would yield rows with data member called count_.

Now, functions do not come with names. While this will lead to lightly more code, the assumption is that this will lead to slightly more readable code, e.g.

SQLPP_ALIAS_PROVIDER(max_price);
// ...
  for (const auto& row : db(select(max(tab.price)).from(tab).unconditionally()))
  {
    std::cout << row.max_price << '\n';
  }

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