I want to use an if statement in a mysql select I know I can use if function and case, but can I achieve the same results with an if statement? can I do it without a stored procedure?
#IF function
SELECT *,if(productLine = 'Motorcycles','Es moto','No es moto' ) as Que_es
from products;
#Case
SELECT *,CASE WHEN productLine = 'Motorcycles'
THEN 'Es moto'
ELSE 'No es moto'
END AS Que_es
from products;
#If... i got problems here
SELECT *,IF productLine='Motorcycles'
THEN 'Es moto'
ELSE 'No es moto'
END IF AS Que_es
from products;
Try using another nested select or try using the alias to perform the select but nothing.
Related
I'm trying to run a somewhat complex sql statement using the 'group_concat' function for statistics.
When I run the sql statement using navicat, the correct result is returned.But when I use mybatis debug this sql in idea, it returns null value.
I use HashMapHashMap<String,Long> to receive the result set executed by mybatis,
I guess the result set returned by mybatis executing sql is wrongly encapsulated.
But I tried for a long time and couldn't find a solution.
I can't post pictures here,I display the results in a table.
cha
hege
lianghao
youxiu
1
1
2
1
Receive declaration at the mapper layer
HashMap<String, Long> getOption(#Param("column") String column);
Here is the sql code:
<select id="getOption" resultType="java.util.HashMap">
SELECT GROUP_CONCAT(form.cha SEPARATOR '') cha,
GROUP_CONCAT(form.hege SEPARATOR '') hege,
GROUP_CONCAT(form.lianghao SEPARATOR '') lianghao,
GROUP_CONCAT(form.youxiu SEPARATOR '') youxiu
FROM (
SELECT
( CASE WHEN #{column} = '0' THEN count(*) ELSE NULL END) AS 'cha',
( CASE WHEN #{column} = '1' THEN count(*) ELSE NULL END ) AS 'hege',
( CASE WHEN #{column} = '2' THEN count(*) ELSE NULL END ) AS 'lianghao',
( CASE WHEN #{column} = '3' THEN count(*) ELSE NULL END ) AS 'youxiu'
FROM corp_feedback_student
GROUP BY #{column}
) form
</select>
Thanks everyone for helping me！！
I need to have an oridinal number from mysql database. I found how emulate of row_num in mysql like this:
SET #row=0;
SELECT * FROM (
SELECT (#row:=#row+1) AS no, id, name FROM `attribute` ORDER BY id
) t WHERE name LIKE "%Jo%"
I begin code with:
$this->getEntityManager()->getConnection()->exec("SET #counter = 0");
and I tried:
$this->result = $this->createQueryBuilder('a')
->select('a')
->where($expr->in('att.ordinal_number', $this->createQueryBuilder('att')->
select('(#counter:=#counter+1) AS ordinal_number')->
from(\App\Entity\Attribute::class, 'att')->
orderBy('att.id')->getDQL()))
and I tried:
$this->result = $this->createQueryBuilder('a')
->select('a')
->addSelect('(SELECT (#counter:=#counter+1) AS oridinal_number, id, '
.' name FROM App:Entity:Atrribute ORDER BY id)')
Above give me:
Error: Expected Literal, got '#'
Anybody know how to emulate row_number in doctrine with mysql?
Thanks in advance.
AFAIK there is no direct way to incorporate these DB variables in DQL or query builder, you will need to execute Native SQL and then use ResultSetMapping class to map the result of query to your entity
SQL
SELECT *
FROM (
SELECT (#row:=#row+1) AS no,
id,
name
FROM `attribute` ,(SELECT #row:=0) t
ORDER BY id
) t WHERE name LIKE "%Jo%"
Resultset Mapping
$rsm = new ResultSetMapping;
$rsm->addEntityResult('Attribute', 'a');
$rsm->addFieldResult('a', 'id', 'id');
$rsm->addFieldResult('a', 'name', 'name');
$rsm->addScalarResult('no', 'no');
$query = $this->_em->createNativeQuery('SELECT *
FROM (
SELECT (#row:=#row+1) AS no,
id,
name
FROM attribute ,(SELECT #row:=0) t
ORDER BY id
) t WHERE name LIKE ?',$rsm);
$query->setParameter(1, '%Jo%');
$users = $query->getResult();
I have the following query:
select coalesce(round(sum(vdamesatual) /
(select count(*)
from feriados
where month(data)=month(current_date) and
day(data)<day(current_date) and
diadasemana in(2,3,4,5,6) and
feriadonacional=0 and
uf <> (select distinct uforigem from baseprodutos where Empresa = 'test'))
*
(select count(*)
from feriados
where month(data)=month(current_date) and
day(data)>=day(current_date) and
diadasemana in(2,3,4,5,6) and
feriadonacional=0 and
uf <> (select distinct uforigem from baseprodutos where Empresa = 'test'))),0) as projecao
from baseprodutos
where Empresa = 'test' and
UFDest = 'uf' and
Fabricante = 'sample';
As you can see I have a coalesce right after the first select, and I am having trouble finding the right way to write this with sequelize; Would you have some suggestion?
I don't really follow the logic of your query, but the rule in Sequelize is that you can call any function with sequelize.fn() so a simple example of using COALESCE in Sequelize to get a value from 2 columns with an alias would be like this in your attributes:
[[sequelize.fn('COALESCE', mysql.col('col_name'), mysql.col('col_2_name')), 'alias'], 'another_col']
You can include another function if needed, like SUM by doing like this:
[[sequelize.fn('COALESCE', sequelize.fn('SUM', (mysql.col('col_name'), mysql.col('col_2_name'))), (some other code here ...)),'alias']]
I have got an error "ERROR: subquery must return only one column " when I am runing this query:
INSERT INTO details (id, object_id, detail)
(
SELECT
CASE
WHEN (SELECT * FROM details WHERE NOT EXISTS(SELECT 1 FROM main_base WHERE main_base.id = details.id))
THEN
concat(SUBSTRING(main_base.id, '(\d+.\d+.)'), n.counted :: TEXT, 'A')
ELSE
concat( SUBSTRING (main_base.id, '(\d+.\d+.)'), n.counted :: TEXT)
END AS id,
main_base.object_id,
main_base.details
FROM main_base
CROSS JOIN LATERAL
generate_series(1, COALESCE ((string_to_array(main_base.id, '-')) [2] :: INT, 1)) AS n (counted)
WHERE main_base.id LIKE '%-%' AND NOT main_base.details ~ '^\.\d+|\(\.\d+\)'
);
I have not clue what is wrong. I've read some topic that people had the same problem but still dont know how to fix it.
I think the problem is that:
SELECT * FROM details WHERE NOT EXISTS(SELECT 1 FROM main_base WHERE main_base.id = details.id)
Can return more than one row, so causes problems in the WHEN statement. It can return more than one row, as the subquery will return 1 every time the condition is met.
If you want to trigger the case statement based on when there exists some records in this set, could you use:
(SELECT COUNT(*) FROM details WHERE NOT EXISTS(SELECT 1 FROM main_base WHERE main_base.id = details.id)) > 1
Can I use REPLACE function conditionally?
e.g. I have a query:
SELECT diag_type FROM DIAGNOSIS
It returns AXIS, AXISI, AXISII, AXIS-C, etc. I want if it returns a result that has AXIS, it makes it AXISIII. Can it be possible?
Thanks in advance.
;with DIAGNOSIS(diag_type) as
(
select 'AXIS' union all
select 'AXISI' union all
select 'AXISII' union all
select 'AXIS-C'
)
select
case diag_type
when 'AXIS' then 'AXISIII'
else diag_type
end as diag_type
from DIAGNOSIS
Result:
diag_type
---------
AXISIII
AXISI
AXISII
AXIS-C
If all you want is it to return AXISIII you can just write:
SELECT 'AXISIII' FROM DIAGNOSIS WHERE diag_type = 'AXIS'
You can also use a CASE-statement to add more options (if you need).
SELECT CASE(diag_type)
WHEN 'AXIS' THEN 'AXISIII'
WHEN 'AXIS-C' THEN'AXISIII-C'
WHEN 'AXISII' THEN'AXISII'
ELSE 'Something'
END
FROM DIAGNOSIS