SQT_PRIMARY_KEY

#define SQT_PRIMARY_KEY

(

...

)

Value:

__SQT_PRIMARY_KEY(false, __VA_ARGS__)

Defines a primary key with the specified columns.

Parameters

...	The names of the columns that form the primary key. A primary key can be composed of one or more columns.

This macro must be used between the SQT_TABLE_BEGIN and SQT_TABLE_END macros and must be placed after all definitions of the columns that are part of the primary key. There can be only one primary key definition in a table type.

Columns of the primary key must not be nullable.

To define an autoincrement primary key, use the SQT_PRIMARY_KEY_AUTO_INC macro instead.

Example usage:

struct MyEntity {
    int id{};
    std::string name;
};
 
SQT_TABLE_BEGIN(MyEntityTable, MyEntity)
SQT_COLUMN_FIELD(ID, id)
SQT_COLUMN_FIELD(Name, name)
// Define the primary key with the ID and Name columns.
SQT_PRIMARY_KEY(ID, Name)
SQT_TABLE_END

The following code demonstrates the generated definition of the primary key in the table type:

class TableType {
public:
    // Column types.
    class IDType;
    class NameType;
 
    // The class name of the primary key type is fixed.
    class PrimaryKeyType : public sqt::PrimaryKey<IDType, NameType> {
    public:
        // Forbids copying.
        PrimaryKeyType(const PrimaryKeyType&) = delete;
        PrimaryKeyType& operator=(const PrimaryKeyType&) = delete;
 
        // Forbids moving.
        PrimaryKeyType(PrimaryKeyType&&) = delete;
        PrimaryKeyType& operator=(PrimaryKeyType&&) = delete;
 
        // Assignment operator that generates an assignment expression.
        constexpr auto operator=(const ValueType&) const noexcept;
 
        // Ordering operator that generates an ordering term expression.
        constexpr auto Asc() const noexcept;
        constexpr auto Desc() const noexcept;
 
        // Comparison operators that generate predicate expressions.
        // Here shows only the == operator. Other operators (!=, <, <=, >, >=) are omitted.
        friend constexpr auto operator==(const PrimaryKeyType&, const ValueType&) const noexcept;
        friend constexpr auto operator==(const PrimaryKeyType&, sqt::Placeholder) const noexcept;
        friend constexpr auto operator==(const ValueType&, const PrimaryKeyType&) const noexcept;
        friend constexpr auto operator==(sqt::Placeholder, const PrimaryKeyType&) const noexcept;
    };
 
    // The instance of the primary key, which is defined as a public member variable of the 
    // table type. The name of the variable is fixed.
    PrimaryKeyType PrimaryKey;
};

See also

SQT_TABLE_BEGIN

SQT_COLUMN_FIELD

SQT_PRIMARY_KEY_AUTO_INC

sqt::PrimaryKey<>