psappho

CREATE TABLE blog_entry (
    written_by VARCHAR(32) NOT NULL,
    entry_date DATE NOT NULL,
    favs INT NOT NULL
)
;
ALTER TABLE blog_entry ADD CONSTRAINT UNIQUE (written_by, entry_date)
;

INSERT INTO blog_entry VALUES

psappho

/* **************************
ランキングを求める : MySQL
************************** */
create table products (
    name varchar(32) not null,
    price int not null
)
;

insert into products values

psappho

create temporary table lovers
select * from (
    select 'shidou' school, 'ギイ' pair1, '託生' pair2, TRUE is_coupled
    union all select 'shidou' school, '三洲' pair1, '真行寺' pair2, TRUE is_coupled
    union all select NULL school, '赤池' pair1, NULL pair2, FALSE is_coupled
) X
;

select * from lovers
;

psappho

create table emp (
    id int primary key auto_increment,
    name varchar(32) not null unique, salary int not null
)
;
insert into emp (name, salary) values ('foo', 250000), ('bar', 320000), ('baz', 130000);

select
    id, name, salary old_salary,
    case