dev/conditions.h - master - UCS/sqlite_orm

dev/conditions.h
1 265 строк37 KB
klaus triendl
Renamed everything related to former 'storage impl' to 'db object'
05 июн 2022, 11:52
05 июн 2022, 11:529726e82
#pragma once

#include <string>  //  std::string
#include <type_traits>  //  std::enable_if, std::is_same
#include <vector>  //  std::vector
#include <tuple>  //  std::tuple, std::tuple_size
#include <sstream>  //  std::stringstream

#include "functional/cxx_universal.h"
#include "functional/cxx_type_traits_polyfill.h"
#include "type_traits.h"
#include "collate_argument.h"
#include "constraints.h"
#include "optional_container.h"
#include "serializer_context.h"
#include "tags.h"
#include "expression.h"
#include "type_printer.h"
#include "literal.h"

namespace sqlite_orm {

    namespace internal {

        struct limit_string {
            operator std::string() const {
                return "LIMIT";
            }
        };

        /**
         *  Stores LIMIT/OFFSET info
         */
        template<class T, bool has_offset, bool offset_is_implicit, class O>
        struct limit_t : limit_string {
            T lim;
            optional_container<O> off;

            limit_t() = default;

            limit_t(decltype(lim) lim_) : lim(std::move(lim_)) {}

            limit_t(decltype(lim) lim_, decltype(off) off_) : lim(std::move(lim_)), off(std::move(off_)) {}
        };

        template<class T>
        struct is_limit : std::false_type {};

        template<class T, bool has_offset, bool offset_is_implicit, class O>
        struct is_limit<limit_t<T, has_offset, offset_is_implicit, O>> : std::true_type {};

        /**
         *  Stores OFFSET only info
         */
        template<class T>
        struct offset_t {
            T off;
        };

        template<class T>
        using is_offset = polyfill::is_specialization_of<T, offset_t>;

        /**
         *  Collated something
         */
        template<class T>
        struct collate_t : public condition_t {
            T expr;
            collate_argument argument;

            collate_t(T expr_, collate_argument argument_) : expr(std::move(expr_)), argument(argument_) {}

            operator std::string() const {
                return collate_constraint_t{this->argument};
            }
        };

        struct named_collate_base {
            std::string name;

            operator std::string() const {
                return "COLLATE " + this->name;
            }
        };

        /**
         *  Collated something with custom collate function
         */
        template<class T>
        struct named_collate : named_collate_base {
            T expr;

            named_collate(T expr_, std::string name_) : named_collate_base{std::move(name_)}, expr(std::move(expr_)) {}
        };

        struct negated_condition_string {
            operator std::string() const {
                return "NOT";
            }
        };

        /**
         *  Result of not operator
         */
        template<class C>
        struct negated_condition_t : condition_t, negated_condition_string {
            C c;

            negated_condition_t(C c_) : c(std::move(c_)) {}
        };

        /**
         *  Base class for binary conditions
         *  L is left argument type
         *  R is right argument type
         *  S is 'string' class (a class which has cast to `std::string` operator)
         *  Res is result type
         */
        template<class L, class R, class S, class Res>
        struct binary_condition : condition_t, S {
            using left_type = L;
            using right_type = R;
            using result_type = Res;

            left_type l;
            right_type r;

            binary_condition() = default;

            binary_condition(left_type l_, right_type r_) : l(std::move(l_)), r(std::move(r_)) {}
        };

        struct and_condition_string {
            operator std::string() const {
                return "AND";
            }
        };

        /**
         *  Result of and operator
         */
        template<class L, class R>
        struct and_condition_t : binary_condition<L, R, and_condition_string, bool> {
            using super = binary_condition<L, R, and_condition_string, bool>;

            using super::super;
        };

        template<class L, class R>
        and_condition_t<L, R> make_and_condition(L left, R right) {
            return {std::move(left), std::move(right)};
        }

        struct or_condition_string {
            operator std::string() const {
                return "OR";
            }
        };

        /**
         *  Result of or operator
         */
        template<class L, class R>
        struct or_condition_t : binary_condition<L, R, or_condition_string, bool> {
            using super = binary_condition<L, R, or_condition_string, bool>;

            using super::super;
        };

        template<class L, class R>
        or_condition_t<L, R> make_or_condition(L left, R right) {
            return {std::move(left), std::move(right)};
        }

        struct is_equal_string {
            operator std::string() const {
                return "=";
            }
        };

        /**
         *  = and == operators object
         */
        template<class L, class R>
        struct is_equal_t : binary_condition<L, R, is_equal_string, bool>, negatable_t {
            using self = is_equal_t<L, R>;

            using binary_condition<L, R, is_equal_string, bool>::binary_condition;

            collate_t<self> collate_binary() const {
                return {*this, collate_argument::binary};
            }

            collate_t<self> collate_nocase() const {
                return {*this, collate_argument::nocase};
            }

            collate_t<self> collate_rtrim() const {
                return {*this, collate_argument::rtrim};
            }

            named_collate<self> collate(std::string name) const {
                return {*this, std::move(name)};
            }

            template<class C>
            named_collate<self> collate() const {
                std::stringstream ss;
                ss << C::name() << std::flush;
                return {*this, ss.str()};
            }
        };

        struct is_not_equal_string {
            operator std::string() const {
                return "!=";
            }
        };

        /**
         *  != operator object
         */
        template<class L, class R>
        struct is_not_equal_t : binary_condition<L, R, is_not_equal_string, bool>, negatable_t {
            using self = is_not_equal_t<L, R>;

            using binary_condition<L, R, is_not_equal_string, bool>::binary_condition;

            collate_t<self> collate_binary() const {
                return {*this, collate_argument::binary};
            }

            collate_t<self> collate_nocase() const {
                return {*this, collate_argument::nocase};
            }

            collate_t<self> collate_rtrim() const {
                return {*this, collate_argument::rtrim};
            }
        };

        struct greater_than_string {
            operator std::string() const {
                return ">";
            }
        };

        /**
         *  > operator object.
         */
        template<class L, class R>
        struct greater_than_t : binary_condition<L, R, greater_than_string, bool>, negatable_t {
            using self = greater_than_t<L, R>;

            using binary_condition<L, R, greater_than_string, bool>::binary_condition;

            collate_t<self> collate_binary() const {
                return {*this, collate_argument::binary};
            }

            collate_t<self> collate_nocase() const {
                return {*this, collate_argument::nocase};
            }

            collate_t<self> collate_rtrim() const {
                return {*this, collate_argument::rtrim};
            }
        };

        struct greater_or_equal_string {
            operator std::string() const {
                return ">=";
            }
        };

        /**
         *  >= operator object.
         */
        template<class L, class R>
        struct greater_or_equal_t : binary_condition<L, R, greater_or_equal_string, bool>, negatable_t {
            using self = greater_or_equal_t<L, R>;

            using binary_condition<L, R, greater_or_equal_string, bool>::binary_condition;

            collate_t<self> collate_binary() const {
                return {*this, collate_argument::binary};
            }

            collate_t<self> collate_nocase() const {
                return {*this, collate_argument::nocase};
            }

            collate_t<self> collate_rtrim() const {
                return {*this, collate_argument::rtrim};
            }
        };

        struct lesser_than_string {
            operator std::string() const {
                return "<";
            }
        };

        /**
         *  < operator object.
         */
        template<class L, class R>
        struct lesser_than_t : binary_condition<L, R, lesser_than_string, bool>, negatable_t {
            using self = lesser_than_t<L, R>;

            using binary_condition<L, R, lesser_than_string, bool>::binary_condition;

            collate_t<self> collate_binary() const {
                return {*this, collate_argument::binary};
            }

            collate_t<self> collate_nocase() const {
                return {*this, collate_argument::nocase};
            }

            collate_t<self> collate_rtrim() const {
                return {*this, collate_argument::rtrim};
            }
        };

        struct lesser_or_equal_string {
            operator std::string() const {
                return "<=";
            }
        };

        /**
         *  <= operator object.
         */
        template<class L, class R>
        struct lesser_or_equal_t : binary_condition<L, R, lesser_or_equal_string, bool>, negatable_t {
            using self = lesser_or_equal_t<L, R>;

            using binary_condition<L, R, lesser_or_equal_string, bool>::binary_condition;

            collate_t<self> collate_binary() const {
                return {*this, collate_argument::binary};
            }

            collate_t<self> collate_nocase() const {
                return {*this, collate_argument::nocase};
            }

            collate_t<self> collate_rtrim() const {
                return {*this, collate_argument::rtrim};
            }
        };

        struct in_base {
            bool negative = false;  //  used in not_in

#ifndef SQLITE_ORM_AGGREGATE_NSDMI_SUPPORTED
            in_base(bool negative) : negative{negative} {}
#endif
        };

        /**
         *  IN operator object.
         */
        template<class L, class A>
        struct dynamic_in_t : condition_t, in_base, negatable_t {
            using self = dynamic_in_t<L, A>;

            L left;  //  left expression
            A argument;  //  in arg

            dynamic_in_t(L left_, A argument_, bool negative_) :
                in_base{negative_}, left(std::move(left_)), argument(std::move(argument_)) {}
        };

        template<class L, class... Args>
        struct in_t : condition_t, in_base, negatable_t {
            L left;
            std::tuple<Args...> argument;

            in_t(L left_, decltype(argument) argument_, bool negative_) :
                in_base{negative_}, left(std::move(left_)), argument(std::move(argument_)) {}
        };

        struct is_null_string {
            operator std::string() const {
                return "IS NULL";
            }
        };

        /**
         *  IS NULL operator object.
         */
        template<class T>
        struct is_null_t : is_null_string, negatable_t {
            using self = is_null_t<T>;

            T t;

            is_null_t(T t_) : t(std::move(t_)) {}
        };

        struct is_not_null_string {
            operator std::string() const {
                return "IS NOT NULL";
            }
        };

        /**
         *  IS NOT NULL operator object.
         */
        template<class T>
        struct is_not_null_t : is_not_null_string, negatable_t {
            using self = is_not_null_t<T>;

            T t;

            is_not_null_t(T t_) : t(std::move(t_)) {}
        };

        struct order_by_base {
            int asc_desc = 0;  //  1: asc, -1: desc
            std::string _collate_argument;

#ifndef SQLITE_ORM_AGGREGATE_NSDMI_SUPPORTED
            order_by_base() = default;

            order_by_base(decltype(asc_desc) asc_desc_, decltype(_collate_argument) _collate_argument_) :
                asc_desc(asc_desc_), _collate_argument(move(_collate_argument_)) {}
#endif
        };

        struct order_by_string {
            operator std::string() const {
                return "ORDER BY";
            }
        };

        /**
         *  ORDER BY argument holder.
         */
        template<class O>
        struct order_by_t : order_by_base, order_by_string {
            using expression_type = O;
            using self = order_by_t<expression_type>;

            expression_type expression;

            order_by_t(expression_type expression_) : order_by_base(), expression(std::move(expression_)) {}

            self asc() const {
                auto res = *this;
                res.asc_desc = 1;
                return res;
            }

            self desc() const {
                auto res = *this;
                res.asc_desc = -1;
                return res;
            }

            self collate_binary() const {
                auto res = *this;
                res._collate_argument = collate_constraint_t::string_from_collate_argument(collate_argument::binary);
                return res;
            }

            self collate_nocase() const {
                auto res = *this;
                res._collate_argument = collate_constraint_t::string_from_collate_argument(collate_argument::nocase);
                return res;
            }

            self collate_rtrim() const {
                auto res = *this;
                res._collate_argument = collate_constraint_t::string_from_collate_argument(collate_argument::rtrim);
                return res;
            }

            self collate(std::string name) const {
                auto res = *this;
                res._collate_argument = std::move(name);
                return res;
            }

            template<class C>
            self collate() const {
                std::stringstream ss;
                ss << C::name() << std::flush;
                return this->collate(ss.str());
            }
        };

        /**
         *  ORDER BY pack holder.
         */
        template<class... Args>
        struct multi_order_by_t : order_by_string {
            using args_type = std::tuple<Args...>;

            args_type args;

            multi_order_by_t(args_type args_) : args{std::move(args_)} {}
        };

        struct dynamic_order_by_entry_t : order_by_base {
            std::string name;

            dynamic_order_by_entry_t(decltype(name) name_, int asc_desc_, std::string collate_argument_) :
                order_by_base{asc_desc_, move(collate_argument_)}, name(move(name_)) {}
        };

        /**
         *  C - serializer context class
         */
        template<class C>
        struct dynamic_order_by_t : order_by_string {
            using context_t = C;
            using entry_t = dynamic_order_by_entry_t;
            using const_iterator = typename std::vector<entry_t>::const_iterator;

            dynamic_order_by_t(const context_t& context_) : context(context_) {}

            template<class O>
            void push_back(order_by_t<O> order_by) {
                auto newContext = this->context;
                newContext.skip_table_name = true;
                auto columnName = serialize(order_by.expression, newContext);
                entries.emplace_back(move(columnName), order_by.asc_desc, move(order_by._collate_argument));
            }

            const_iterator begin() const {
                return this->entries.begin();
            }

            const_iterator end() const {
                return this->entries.end();
            }

            void clear() {
                this->entries.clear();
            }

          protected:
            std::vector<entry_t> entries;
            context_t context;
        };

        template<class T>
        SQLITE_ORM_INLINE_VAR constexpr bool is_order_by_v =
            polyfill::disjunction_v<polyfill::is_specialization_of<T, order_by_t>,
                                    polyfill::is_specialization_of<T, multi_order_by_t>,
                                    polyfill::is_specialization_of<T, dynamic_order_by_t>>;

        template<class T>
        using is_order_by = polyfill::bool_constant<is_order_by_v<T>>;

        struct between_string {
            operator std::string() const {
                return "BETWEEN";
            }
        };

        /**
         *  BETWEEN operator object.
         */
        template<class A, class T>
        struct between_t : condition_t, between_string {
            using expression_type = A;
            using lower_type = T;
            using upper_type = T;

            expression_type expr;
            lower_type b1;
            upper_type b2;

            between_t(expression_type expr_, lower_type b1_, upper_type b2_) :
                expr(std::move(expr_)), b1(std::move(b1_)), b2(std::move(b2_)) {}
        };

        struct like_string {
            operator std::string() const {
                return "LIKE";
            }
        };

        /**
         *  LIKE operator object.
         */
        template<class A, class T, class E>
        struct like_t : condition_t, like_string, negatable_t {
            using self = like_t<A, T, E>;
            using arg_t = A;
            using pattern_t = T;
            using escape_t = E;

            arg_t arg;
            pattern_t pattern;
            optional_container<escape_t> arg3;  //  not escape cause escape exists as a function here

            like_t(arg_t arg_, pattern_t pattern_, optional_container<escape_t> escape_) :
                arg(std::move(arg_)), pattern(std::move(pattern_)), arg3(std::move(escape_)) {}

            template<class C>
            like_t<A, T, C> escape(C c) const {
                optional_container<C> newArg3{std::move(c)};
                return {std::move(this->arg), std::move(this->pattern), std::move(newArg3)};
            }
        };

        struct glob_string {
            operator std::string() const {
                return "GLOB";
            }
        };

        template<class A, class T>
        struct glob_t : condition_t, glob_string, internal::negatable_t {
            using self = glob_t<A, T>;
            using arg_t = A;
            using pattern_t = T;

            arg_t arg;
            pattern_t pattern;

            glob_t(arg_t arg_, pattern_t pattern_) : arg(std::move(arg_)), pattern(std::move(pattern_)) {}
        };

        struct cross_join_string {
            operator std::string() const {
                return "CROSS JOIN";
            }
        };

        /**
         *  CROSS JOIN holder.
         *  T is joined type which represents any mapped table.
         */
        template<class T>
        struct cross_join_t : cross_join_string {
            using type = T;
        };

        struct natural_join_string {
            operator std::string() const {
                return "NATURAL JOIN";
            }
        };

        /**
         *  NATURAL JOIN holder.
         *  T is joined type which represents any mapped table.
         */
        template<class T>
        struct natural_join_t : natural_join_string {
            using type = T;
        };

        struct left_join_string {
            operator std::string() const {
                return "LEFT JOIN";
            }
        };

        /**
         *  LEFT JOIN holder.
         *  T is joined type which represents any mapped table.
         *  O is on(...) argument type.
         */
        template<class T, class O>
        struct left_join_t : left_join_string {
            using type = T;
            using on_type = O;

            on_type constraint;

            left_join_t(on_type constraint_) : constraint(std::move(constraint_)) {}
        };

        struct join_string {
            operator std::string() const {
                return "JOIN";
            }
        };

        /**
         *  Simple JOIN holder.
         *  T is joined type which represents any mapped table.
         *  O is on(...) argument type.
         */
        template<class T, class O>
        struct join_t : join_string {
            using type = T;
            using on_type = O;

            on_type constraint;

            join_t(on_type constraint_) : constraint(std::move(constraint_)) {}
        };

        struct left_outer_join_string {
            operator std::string() const {
                return "LEFT OUTER JOIN";
            }
        };

        /**
         *  LEFT OUTER JOIN holder.
         *  T is joined type which represents any mapped table.
         *  O is on(...) argument type.
         */
        template<class T, class O>
        struct left_outer_join_t : left_outer_join_string {
            using type = T;
            using on_type = O;

            on_type constraint;

            left_outer_join_t(on_type constraint_) : constraint(std::move(constraint_)) {}
        };

        struct on_string {
            operator std::string() const {
                return "ON";
            }
        };

        /**
         *  on(...) argument holder used for JOIN, LEFT JOIN, LEFT OUTER JOIN and INNER JOIN
         *  T is on type argument.
         */
        template<class T>
        struct on_t : on_string {
            using arg_type = T;

            arg_type arg;

            on_t(arg_type arg_) : arg(std::move(arg_)) {}
        };

        /**
         *  USING argument holder.
         */
        template<class T, class M>
        struct using_t {
            column_pointer<T, M> column;

            operator std::string() const {
                return "USING";
            }
        };

        struct inner_join_string {
            operator std::string() const {
                return "INNER JOIN";
            }
        };

        /**
         *  INNER JOIN holder.
         *  T is joined type which represents any mapped table.
         *  O is on(...) argument type.
         */
        template<class T, class O>
        struct inner_join_t : inner_join_string {
            using type = T;
            using on_type = O;

            on_type constraint;

            inner_join_t(on_type constraint_) : constraint(std::move(constraint_)) {}
        };

        struct cast_string {
            operator std::string() const {
                return "CAST";
            }
        };

        /**
         *  CAST holder.
         *  T is a type to cast to
         *  E is an expression type
         *  Example: cast<std::string>(&User::id)
         */
        template<class T, class E>
        struct cast_t : cast_string {
            using to_type = T;
            using expression_type = E;

            expression_type expression;

            cast_t(expression_type expression_) : expression(std::move(expression_)) {}
        };

        template<class... Args>
        struct from_t {
            using tuple_type = std::tuple<Args...>;
        };

        template<class T>
        using is_from = polyfill::is_specialization_of<T, from_t>;
    }

    /**
     *  Explicit FROM function. Usage:
     *  `storage.select(&User::id, from<User>());`
     */
    template<class... Args>
    internal::from_t<Args...> from() {
        static_assert(std::tuple_size<std::tuple<Args...>>::value > 0, "");
        return {};
    }

    template<class T, internal::satisfies<std::is_base_of, internal::negatable_t, T> = true>
    internal::negated_condition_t<T> operator!(T arg) {
        return {std::move(arg)};
    }

    /**
     *  Cute operators for columns
     */
    template<class T, class R>
    internal::lesser_than_t<T, R> operator<(internal::expression_t<T> expr, R r) {
        return {std::move(expr.value), std::move(r)};
    }

    template<class L, class T>
    internal::lesser_than_t<L, T> operator<(L l, internal::expression_t<T> expr) {
        return {std::move(l), std::move(expr.value)};
    }

    template<class T, class R>
    internal::lesser_or_equal_t<T, R> operator<=(internal::expression_t<T> expr, R r) {
        return {std::move(expr.value), std::move(r)};
    }

    template<class L, class T>
    internal::lesser_or_equal_t<L, T> operator<=(L l, internal::expression_t<T> expr) {
        return {std::move(l), std::move(expr.value)};
    }

    template<class T, class R>
    internal::greater_than_t<T, R> operator>(internal::expression_t<T> expr, R r) {
        return {std::move(expr.value), std::move(r)};
    }

    template<class L, class T>
    internal::greater_than_t<L, T> operator>(L l, internal::expression_t<T> expr) {
        return {std::move(l), std::move(expr.value)};
    }

    template<class T, class R>
    internal::greater_or_equal_t<T, R> operator>=(internal::expression_t<T> expr, R r) {
        return {std::move(expr.value), std::move(r)};
    }

    template<class L, class T>
    internal::greater_or_equal_t<L, T> operator>=(L l, internal::expression_t<T> expr) {
        return {std::move(l), std::move(expr.value)};
    }

    template<class T, class R>
    internal::is_equal_t<T, R> operator==(internal::expression_t<T> expr, R r) {
        return {std::move(expr.value), std::move(r)};
    }

    template<class L, class T>
    internal::is_equal_t<L, T> operator==(L l, internal::expression_t<T> expr) {
        return {std::move(l), std::move(expr.value)};
    }

    template<class T, class R>
    internal::is_not_equal_t<T, R> operator!=(internal::expression_t<T> expr, R r) {
        return {std::move(expr.value), std::move(r)};
    }

    template<class L, class T>
    internal::is_not_equal_t<L, T> operator!=(L l, internal::expression_t<T> expr) {
        return {std::move(l), std::move(expr.value)};
    }

    template<class T, class R>
    internal::conc_t<T, R> operator||(internal::expression_t<T> expr, R r) {
        return {std::move(expr.value), std::move(r)};
    }

    template<class L, class T>
    internal::conc_t<L, T> operator||(L l, internal::expression_t<T> expr) {
        return {std::move(l), std::move(expr.value)};
    }

    template<class L, class R>
    internal::conc_t<L, R> operator||(internal::expression_t<L> l, internal::expression_t<R> r) {
        return {std::move(l.value), std::move(r.value)};
    }

    template<class T, class R>
    internal::add_t<T, R> operator+(internal::expression_t<T> expr, R r) {
        return {std::move(expr.value), std::move(r)};
    }

    template<class L, class T>
    internal::add_t<L, T> operator+(L l, internal::expression_t<T> expr) {
        return {std::move(l), std::move(expr.value)};
    }

    template<class L, class R>
    internal::add_t<L, R> operator+(internal::expression_t<L> l, internal::expression_t<R> r) {
        return {std::move(l.value), std::move(r.value)};
    }

    template<class T, class R>
    internal::sub_t<T, R> operator-(internal::expression_t<T> expr, R r) {
        return {std::move(expr.value), std::move(r)};
    }

    template<class L, class T>
    internal::sub_t<L, T> operator-(L l, internal::expression_t<T> expr) {
        return {std::move(l), std::move(expr.value)};
    }

    template<class L, class R>
    internal::sub_t<L, R> operator-(internal::expression_t<L> l, internal::expression_t<R> r) {
        return {std::move(l.value), std::move(r.value)};
    }

    template<class T, class R>
    internal::mul_t<T, R> operator*(internal::expression_t<T> expr, R r) {
        return {std::move(expr.value), std::move(r)};
    }

    template<class L, class T>
    internal::mul_t<L, T> operator*(L l, internal::expression_t<T> expr) {
        return {std::move(l), std::move(expr.value)};
    }

    template<class L, class R>
    internal::mul_t<L, R> operator*(internal::expression_t<L> l, internal::expression_t<R> r) {
        return {std::move(l.value), std::move(r.value)};
    }

    template<class T, class R>
    internal::div_t<T, R> operator/(internal::expression_t<T> expr, R r) {
        return {std::move(expr.value), std::move(r)};
    }

    template<class L, class T>
    internal::div_t<L, T> operator/(L l, internal::expression_t<T> expr) {
        return {std::move(l), std::move(expr.value)};
    }

    template<class L, class R>
    internal::div_t<L, R> operator/(internal::expression_t<L> l, internal::expression_t<R> r) {
        return {std::move(l.value), std::move(r.value)};
    }

    template<class T, class R>
    internal::mod_t<T, R> operator%(internal::expression_t<T> expr, R r) {
        return {std::move(expr.value), std::move(r)};
    }

    template<class L, class T>
    internal::mod_t<L, T> operator%(L l, internal::expression_t<T> expr) {
        return {std::move(l), std::move(expr.value)};
    }

    template<class L, class R>
    internal::mod_t<L, R> operator%(internal::expression_t<L> l, internal::expression_t<R> r) {
        return {std::move(l.value), std::move(r.value)};
    }

    template<class F, class O>
    internal::using_t<O, F O::*> using_(F O::*p) {
        return {p};
    }
    template<class T, class M>
    internal::using_t<T, M> using_(internal::column_pointer<T, M> cp) {
        return {std::move(cp)};
    }

    template<class T>
    internal::on_t<T> on(T t) {
        return {std::move(t)};
    }

    template<class T>
    internal::cross_join_t<T> cross_join() {
        return {};
    }

    template<class T>
    internal::natural_join_t<T> natural_join() {
        return {};
    }

    template<class T, class O>
    internal::left_join_t<T, O> left_join(O o) {
        return {std::move(o)};
    }

    template<class T, class O>
    internal::join_t<T, O> join(O o) {
        return {std::move(o)};
    }

    template<class T, class O>
    internal::left_outer_join_t<T, O> left_outer_join(O o) {
        return {std::move(o)};
    }

    template<class T, class O>
    internal::inner_join_t<T, O> inner_join(O o) {
        return {std::move(o)};
    }

    template<class T>
    internal::offset_t<T> offset(T off) {
        return {std::move(off)};
    }

    template<class T>
    internal::limit_t<T, false, false, void> limit(T lim) {
        return {std::move(lim)};
    }

    template<class T, class O, internal::satisfies_not<internal::is_offset, T> = true>
    internal::limit_t<T, true, true, O> limit(O off, T lim) {
        return {std::move(lim), {std::move(off)}};
    }

    template<class T, class O>
    internal::limit_t<T, true, false, O> limit(T lim, internal::offset_t<O> offt) {
        return {std::move(lim), {std::move(offt.off)}};
    }

    template<class L,
             class R,
             std::enable_if_t<polyfill::disjunction_v<std::is_base_of<internal::condition_t, L>,
                                                      std::is_base_of<internal::condition_t, R>>,
                              bool> = true>
    auto operator&&(L l, R r) {
        using internal::get_from_expression;
        return internal::make_and_condition(std::move(get_from_expression(l)), std::move(get_from_expression(r)));
    }

    template<class L, class R>
    auto and_(L l, R r) {
        using internal::get_from_expression;
        return internal::make_and_condition(std::move(get_from_expression(l)), std::move(get_from_expression(r)));
    }

    template<class L,
             class R,
             std::enable_if_t<polyfill::disjunction_v<std::is_base_of<internal::condition_t, L>,
                                                      std::is_base_of<internal::condition_t, R>>,
                              bool> = true>
    auto operator||(L l, R r) {
        using internal::get_from_expression;
        return internal::make_or_condition(std::move(get_from_expression(l)), std::move(get_from_expression(r)));
    }

    template<class L, class R>
    auto or_(L l, R r) {
        using internal::get_from_expression;
        return internal::make_or_condition(std::move(get_from_expression(l)), std::move(get_from_expression(r)));
    }

    template<class T>
    internal::is_not_null_t<T> is_not_null(T t) {
        return {std::move(t)};
    }

    template<class T>
    internal::is_null_t<T> is_null(T t) {
        return {std::move(t)};
    }

    template<class L, class E>
    internal::dynamic_in_t<L, std::vector<E>> in(L l, std::vector<E> values) {
        return {std::move(l), std::move(values), false};
    }

    template<class L, class E>
    internal::dynamic_in_t<L, std::vector<E>> in(L l, std::initializer_list<E> values) {
        return {std::move(l), std::move(values), false};
    }

    template<class L, class A>
    internal::dynamic_in_t<L, A> in(L l, A arg) {
        return {std::move(l), std::move(arg), false};
    }

    template<class L, class E>
    internal::dynamic_in_t<L, std::vector<E>> not_in(L l, std::vector<E> values) {
        return {std::move(l), std::move(values), true};
    }

    template<class L, class E>
    internal::dynamic_in_t<L, std::vector<E>> not_in(L l, std::initializer_list<E> values) {
        return {std::move(l), std::move(values), true};
    }

    template<class L, class A>
    internal::dynamic_in_t<L, A> not_in(L l, A arg) {
        return {std::move(l), std::move(arg), true};
    }

    template<class L, class R>
    internal::is_equal_t<L, R> is_equal(L l, R r) {
        return {std::move(l), std::move(r)};
    }

    template<class L, class R>
    internal::is_equal_t<L, R> eq(L l, R r) {
        return {std::move(l), std::move(r)};
    }

    template<class L, class R>
    internal::is_not_equal_t<L, R> is_not_equal(L l, R r) {
        return {std::move(l), std::move(r)};
    }

    template<class L, class R>
    internal::is_not_equal_t<L, R> ne(L l, R r) {
        return {std::move(l), std::move(r)};
    }

    template<class L, class R>
    internal::greater_than_t<L, R> greater_than(L l, R r) {
        return {std::move(l), std::move(r)};
    }

    template<class L, class R>
    internal::greater_than_t<L, R> gt(L l, R r) {
        return {std::move(l), std::move(r)};
    }

    template<class L, class R>
    internal::greater_or_equal_t<L, R> greater_or_equal(L l, R r) {
        return {std::move(l), std::move(r)};
    }

    template<class L, class R>
    internal::greater_or_equal_t<L, R> ge(L l, R r) {
        return {std::move(l), std::move(r)};
    }

    template<class L, class R>
    internal::lesser_than_t<L, R> lesser_than(L l, R r) {
        return {std::move(l), std::move(r)};
    }

    template<class L, class R>
    internal::lesser_than_t<L, R> lt(L l, R r) {
        return {std::move(l), std::move(r)};
    }

    template<class L, class R>
    internal::lesser_or_equal_t<L, R> lesser_or_equal(L l, R r) {
        return {std::move(l), std::move(r)};
    }

    template<class L, class R>
    internal::lesser_or_equal_t<L, R> le(L l, R r) {
        return {std::move(l), std::move(r)};
    }

    /**
     * ORDER BY column, column alias or expression
     * 
     * Examples:
     * storage.select(&User::name, order_by(&User::id))
     * storage.select(as<colalias_a>(&User::name), order_by(get<colalias_a>()))
     */
    template<class O, internal::satisfies_not<std::is_base_of, integer_printer, type_printer<O>> = true>
    internal::order_by_t<O> order_by(O o) {
        return {std::move(o)};
    }

    /**
     * ORDER BY positional ordinal
     * 
     * Examples:
     * storage.select(&User::name, order_by(1))
     */
    template<class O, internal::satisfies<std::is_base_of, integer_printer, type_printer<O>> = true>
    internal::order_by_t<internal::literal_holder<O>> order_by(O o) {
        return {{std::move(o)}};
    }

    /**
     * ORDER BY column1, column2
     * Example: storage.get_all<Singer>(multi_order_by(order_by(&Singer::name).asc(), order_by(&Singer::gender).desc())
     */
    template<class... Args>
    internal::multi_order_by_t<Args...> multi_order_by(Args&&... args) {
        return {std::make_tuple(std::forward<Args>(args)...)};
    }

    /**
     * ORDER BY column1, column2
     * Difference from `multi_order_by` is that `dynamic_order_by` can be changed at runtime using `push_back` member
     * function Example:
     *  auto orderBy = dynamic_order_by(storage);
     *  if(someCondition) {
     *      orderBy.push_back(&User::id);
     *  } else {
     *      orderBy.push_back(&User::name);
     *      orderBy.push_back(&User::birthDate);
     *  }
     */
    template<class S>
    internal::dynamic_order_by_t<internal::serializer_context<typename S::db_objects_type>>
    dynamic_order_by(const S& storage) {
        internal::serializer_context_builder<S> builder(storage);
        return builder();
    }

    /**
     *  X BETWEEN Y AND Z
     *  Example: storage.select(between(&User::id, 10, 20))
     */
    template<class A, class T>
    internal::between_t<A, T> between(A expr, T b1, T b2) {
        return {std::move(expr), std::move(b1), std::move(b2)};
    }

    /**
     *  X LIKE Y
     *  Example: storage.select(like(&User::name, "T%"))
     */
    template<class A, class T>
    internal::like_t<A, T, void> like(A a, T t) {
        return {std::move(a), std::move(t), {}};
    }

    /**
     *  X GLOB Y
     *  Example: storage.select(glob(&User::name, "*S"))
     */
    template<class A, class T>
    internal::glob_t<A, T> glob(A a, T t) {
        return {std::move(a), std::move(t)};
    }

    /**
     *  X LIKE Y ESCAPE Z
     *  Example: storage.select(like(&User::name, "T%", "%"))
     */
    template<class A, class T, class E>
    internal::like_t<A, T, E> like(A a, T t, E e) {
        return {std::move(a), std::move(t), {std::move(e)}};
    }

    /**
     *  CAST(X AS type).
     *  Example: cast<std::string>(&User::id)
     */
    template<class T, class E>
    internal::cast_t<T, E> cast(E e) {
        return {std::move(e)};
    }
}