insert into tag_category (t_name, is_category)
values (#{name}, true);
update tag_category
set t_name=#{name}
where t_id = #{id}
and is_category = true
update tag_category
set is_delete= true
where t_id = #{id}
and is_category = true
select *
from tag_category
where t_name = #{name}
and is_category = true
select *
from tag_category
where t_id = #{id}
and is_category = true
select *
from tag_category
where is_category = true
select t_name
from tag_category
where is_category = true
select t_name
from tag_category
where is_category = true
and t_id = #{id}
select t_id
from tag_category
where is_category = true
and t_name = #{name}
SELECT EXISTS(SELECT * FROM tag_category WHERE t_name = #{name} and is_category = true)
SELECT EXISTS(SELECT * FROM tag_category WHERE t_id = #{id})
select *
from tag_category
where is_category = true
order by t_id desc
limit 1;
select count(*)
from tag_category
where is_category = true
and is_delete = false;