數據庫學習筆記---pgsql

創建表

drop table test_create_table;

create table test_create_table (
    id int8 not null primary key ,
    user_id int8 not null,
    user_name varchar(20) not null default '',
    user_sex boolean
)

給主鍵設置自增（需要先設置sequence）

 /*增加自增索引*/
create sequence id;
alter table test_create_table alter column id set default nextval('id');

添加索引

create unique index unq_user_id_user_name on test_create_table(user_id,user_name)

/*設置更新觸發器函數*/
create or replace function upd_timestamp() returns trigger as
$$
begin
    new.update_time = current_timestamp;
    return new;
end
$$
language plpgsql;

/*創建觸發器*/
create trigger trigger_test_study
    before update
    on test_create_table
    for each row
execute procedure upd_timestamp();