#pg_sql之增删改查
#修改:
inset into table_name
(id,
name,
age,
address
)
select
replace(old_id,old_id,new_id),#old_id字段的old_id数据,替换为new_id
replace(name,name,substring(concat('【新名字】'),name),1,20)),#name字段替换为【新名字】+name
20,
address
from
table_name
where
id ='201901'
#增加
inset into table_name
(id,
name,
age,
address,
date
)
values(
'201901',
'xiaoming',
'23',
'上海',
TO_DATE('2006-03-01','YYYY-MM-DD'))
#更新
update table_name
set id =3
where id = 2 and name ='xiaoming'
#联表搜索 join on
mybatis注解多条件查询
@Selct({"<script>"+"查询语句"+"</script>"})
List<DemoBo> getListByForm(Page<DemoBo> page,DemoForm demoForm)
查询语句如下:
select
A.id,
B.name,
A.address,
A.age
from table_nameA as A
left join table_nameB as B on A.id = B.id
where A.id = 0
<if test 'id != null'> and A.id <![CDATA[=]]> #{id}</if>
<if test 'name != null'> and A.name <![CDATA[=]]> #{name}</if>
order by A.age desc,A.id desc
#条件判断 case when
selct a.id ,a.name,a.age
case when
b.begindate = b.enddate
then 1
else 0
end as f_date
from table_nameA as a
inner join(
selct id,
count(*) as count,
sum(case when age =2 then 1 else 0 end) as age
from table_nameB
group by id
) as b on a.id = b.id
where a.id =1232