subcrip
/
db-lab1
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

add db optional support

This commit is contained in:
jie 2021-11-15 15:32:36 +08:00
parent be3b0d11a1
commit 8dd5facce7
1 changed files with 41 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

41
WebApp/bserv/include/bserv/database.hpp
View File

@ -27,6 +27,7 @@ namespace bserv {
const char* c_str() const { return field_.c_str(); }
template <typename Type>
Type as() const { return field_.as<Type>(); }
bool is_null() const { return field_.is_null(); }
};
class db_row {
@ -160,6 +161,20 @@ namespace bserv {
}
};
template <typename Type>
class db_value<std::optional<Type>> : public db_parameter {
private:
std::optional<Type> value_;
public:
db_value(const std::optional<Type>& value)
: value_{ value } {}
std::string get_value(raw_db_transaction_type& tx) {
return value_.has_value()
? db_value<Type>{value_.value()}.get_value(tx)
: "null";
}
};
template <typename Type>
class db_value<std::vector<Type>> : public db_parameter {
private:
@ -243,6 +258,32 @@ namespace bserv {
}
};
template <typename Type>
class db_field<std::optional<Type>> : public db_field_holder {
public:
using db_field_holder::db_field_holder;
void add(
const db_row& row, std::size_t field_idx,
boost::json::object& obj) {
if (!row[field_idx].is_null()) {
obj[name_] = row[field_idx].as<Type>();
}
}
};
template <>
class db_field<std::optional<std::string>> : public db_field_holder {
public:
using db_field_holder::db_field_holder;
void add(
const db_row& row, std::size_t field_idx,
boost::json::object& obj) {
if (!row[field_idx].is_null()) {
obj[name_] = row[field_idx].c_str();
}
}
};
} // db_internal
template <typename Type>