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#pragma once
#include <database/select_query.hpp>
#include <database/type_to_sql.hpp>
#include <database/row.hpp>
#include <algorithm>
#include <string>
#include <set>
using namespace std::string_literals;
std::set<std::string> get_all_columns_from_table(sqlite3* db, const std::string& table_name);
template <typename ColumnType>
void add_column_to_table(sqlite3* db, const std::string& table_name)
{
const std::string name = ColumnType::name;
std::string query{"ALTER TABLE " + table_name + " ADD " + ColumnType::name + " " + TypeToSQLType<typename ColumnType::real_type>::type};
char* error;
const auto result = sqlite3_exec(db, query.data(), nullptr, nullptr, &error);
if (result != SQLITE_OK)
{
log_error("Error adding column ", name, " to table ", table_name, ": ", error);
sqlite3_free(error);
}
}
template <typename ColumnType, decltype(ColumnType::options) = nullptr>
void append_option(std::string& s)
{
s += " "s + ColumnType::options;
}
template <typename>
void append_option(...)
{ }
template <typename... T>
class Table
{
static_assert(sizeof...(T) > 0, "Table cannot be empty");
using ColumnTypes = std::tuple<T...>;
public:
using RowType = Row<T...>;
Table(std::string name):
name(std::move(name))
{}
void upgrade(sqlite3* db)
{
const auto existing_columns = get_all_columns_from_table(db, this->name);
add_column_if_not_exists(db, existing_columns);
}
void create(sqlite3* db)
{
std::string res{"CREATE TABLE IF NOT EXISTS "};
res += this->name;
res += " (\n";
this->add_column_create(res);
res += ")";
char* error;
const auto result = sqlite3_exec(db, res.data(), nullptr, nullptr, &error);
if (result != SQLITE_OK)
{
log_error("Error executing query: ", error);
sqlite3_free(error);
}
}
RowType row()
{
return {this->name};
}
SelectQuery<T...> select()
{
SelectQuery<T...> select(this->name);
return select;
}
const std::string& get_name() const
{
return this->name;
}
private:
template <std::size_t N=0>
typename std::enable_if<N < sizeof...(T), void>::type
add_column_if_not_exists(sqlite3* db, const std::set<std::string>& existing_columns)
{
using ColumnType = typename std::remove_reference<decltype(std::get<N>(std::declval<ColumnTypes>()))>::type;
if (existing_columns.count(ColumnType::name) != 1)
{
add_column_to_table<ColumnType>(db, this->name);
}
add_column_if_not_exists<N+1>(db, existing_columns);
}
template <std::size_t N=0>
typename std::enable_if<N == sizeof...(T), void>::type
add_column_if_not_exists(sqlite3*, const std::set<std::string>&)
{}
template <std::size_t N=0>
typename std::enable_if<N < sizeof...(T), void>::type
add_column_create(std::string& str)
{
using ColumnType = typename std::remove_reference<decltype(std::get<N>(std::declval<ColumnTypes>()))>::type;
using RealType = typename ColumnType::real_type;
str += ColumnType::name;
str += " ";
str += TypeToSQLType<RealType>::type;
append_option<ColumnType>(str);
if (N != sizeof...(T) - 1)
str += ",";
str += "\n";
add_column_create<N+1>(str);
}
template <std::size_t N=0>
typename std::enable_if<N == sizeof...(T), void>::type
add_column_create(std::string&)
{ }
const std::string name;
};
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