mysql复合主键和联合主键的区别浅谈_mysql联合主键和复合主键

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create table index_test

(

    a int not null,

    b int not null,

    c int not null,

    d int null,

    primary key (c, a, b)

);

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create table index_test_a

(

    id int not null,

    a int not null

    primary key (id)

);

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create table index_test_b

(

    id int not null,

    b int not null

    primary key (id)

);

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create table index_test_a_b

(

    id int not null,

    a_id int not null,

    b_id int not null,

    primary key (id)

);

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index_test_a_b表的id为表index_test_a和表index_test_b的联合主键，就是个逻辑概念