get the label through the foreign key - mysql

These are my table.
My tables are
User table
id Name Sex
1 bob 1
2 taro 1
3 can 2
Sex table
id label
1 male
2 female
User.sex is foreign key of Sex.id
What I want to get is like this below
Name Sex
bob male
taro female
can female
$query = $em->createQuery(
SELECT a,id,a.sex
FROM UserBundle:User a)
it says
[Semantical Error] line 0, col 97 near 'sex': Error: Invalid PathExpression. Must be a StateFieldPathExpression
I guess Identity could help this problem.
So I tried such as
$query = $em->createQuery(
SELECT a,id,IDENTITY(a.sex) AS sex
FROM UserBundle:User a)
$user = $query->getResult();
$user[0]['sex'] //
it shows '1'(id) but I wan to show the label name
please give some hint.
thanks alot

The canonical way to accomplish this task in SQL is to use a subquery. Something to the effect of:
Select u.name s.label
From user u, sex s
where s.ID in (Select sex
from u
where u.id = 1);
will get you any one user record with a labeled sex.
so you'll need to modify your prepared statement in such a way as to run a subquery.
For multiple records in the result set, you may consider phrasing your SQL statement using an inner join.
Select u.name s.label
from user u inner join sex s
on u.sex = s.id;
will get you a matched set of each user's name and the label for their gender.
It looks like you're using something like a scripting language prepared statement functionality (is that php?), so make sure to read over your language's syntax on properly setting up a prepared statement to avoid an injection attack from a malicious user.

Related

Don't want to fetch single column (name)

def fetchProposalByStudio(studioId: Int): List[ProposalDetails] = {
ConnectionPoolManager.getDB(config = appConfig).localTx { implicit session: DBSession =>
logger.info("Querying proposal table to fetch all the proposals")
SQL("""SELECT [except name] p.id, id, proposal_title, challenge, possible_solution, explanation,
| submission_date, status, submitted_by, remark
| FROM proposal p inner join knolder k on k.id = p.knolder_id
| where k.studio_id =? order by p.id desc""".stripMargin)
.bind(studioId)
.map(rs =>
ProposalDetails(
rs.int("id"),
rs.int("id"),
rs.string("proposal_title"),
rs.string("challenge"),
rs.string("possible_solution"),
rs.string("explanation"),
rs.string("submission_date"),
Some(ProposalStatus.withName(rs.string("status"))),
rs.string("submitted_by"),
rs.string("remark"),
**rs.string("name")**
)
)
.list().apply()
}
}
I don't want to fetch this column name in my query but without involving this in the query i am getting this error due to using case class.
13:28:24.446 [default-akka.actor.default-dispatcher-8] INFO c.k.l.b.ProposalImpl - Something went wrong while fetching the proposals. Exception message: ERROR: syntax error at or near "["
Position: 8
Smells of a syntax problem...
Perhaps:
SELECT [except name] -- should be
SELECT `except name` -- in mysql
If you don't want a particular column in an SQL resultset, you simply don't mention it in the SELECT.
There is no notion of SELECT * EXCEPT FirstName FROM person - if Person has FirstName, LastName, Age, Address and you don't want FirstName, you don't put it in the select list:
SELECT LastName, Age, Address FROM Person
^^^^^^^
no FirstName mentioned here
Mention every column you do want, do not mention any column you don't want.
If the complaint is "but there are 527 columns and I want all except one" - you can do something like:
SELECT CONCAT(column_name, ',') FROM information_schema.columns WHERE table_name = 'Person' and column_name <> 'FirstName'
which produces a resultset like:
LastName,
Age,
Address,
... 523 other columns
And you can then copy that resultset and paste it into your code, and it already has commas on the end..
If you want the columns all on one line, use GROUP_CONCAT or use a decent text editor to replace \r\n with nothing. If you want to surround the column name in backticks, put it into the CONCAT.. The ultimate point here is that you're a software developer: you can write code that writes code, then you can copy the output, which is valid code, and paste it into some other code somewhere else

Joining and filtering one-to-many relationship

I need some help about optimal structuring of SQL query. I have model like this:
I'm trying some kind of join between tables NON_NATURAL_PERSON and NNP_NAME. Because I have many names in table NNP_NAME for one person I can't do one-to-one SELECT * from NON_NATURAL_PERSON inner join NNP_NAME etc. That way I'll get extra rows for every name one person has.
Data in tables:
How to extend this query to get rows marked red on picture shown below? My wannabe query criteria is: Always join name of typeA only if exists. If not, join name of typeB. If neither exists join name of typeC.
SELECT nnp.ID, name.NAME, name.TYPE
FROM NON_NATURAL_PERSON nnp
INNER JOIN NNP_NAME name ON (name.NON_NATURAL_PERSON = nnp.ID)
If type is spelled exactly as it's written (typeA, typeB, typeC) then you can use MIN() function:
SELECT NON_NATURAL_PERSON, MIN(type) AS min_type
FROM NNP_NAME
GROUP BY NON_NATURAL_PERSON
if you also want the username you can use this query:
SELECT
n1.NON_NATURAL_PERSON AS ID,
n1.Name,
n1.Type
FROM
NNP_NAME n1 LEFT JOIN NNP_NAME n2
ON n1.NON_NATURAL_PERSON = n2.NON_NATURAL_PERSON
AND n1.Type > n2.type
WHERE
n2.type IS NULL
Please see this fiddle. If Types are not literally sorted, change this line:
AND n1.Type > n2.type
with this:
AND FIELD(n1.Type, 'TypeA', 'TypeB', 'TypeC') >
FIELD(n2.type, 'TypeA', 'TypeB', 'TypeC')
MySQL FIELD(str, str1, str2, ...) function returns the index (position) of str in the str1, str2, ... list, and 0 if str is not found. You want to get the "first" record, ordered by type, for every NON_NATURAL_PERSON. There are multiple ways to get this info, I chose a self join:
ON n1.NON_NATURAL_PERSON = n2.NON_NATURAL_PERSON
AND n1.Type > n2.type -- or filed function
with the WHERE condition:
WHERE n2.type IS NULL
this will return all rows where the join didn't succeed - the join won't succeed when there is not n2.type that is less than n1.type - it will return the first record.
Edit
If you want a platform independent solution, avoiding the creation of new tables, you could use CASE WHEN, just change
AND n1.Type > n2.Type
with
AND
CASE
WHEN n1.Type='TypeA' THEN 1
WHEN n1.Type='TypeB' THEN 2
WHEN n1.Type='TypeC' THEN 3
END
>
CASE
WHEN n2.Type='TypeA' THEN 1
WHEN n2.Type='TypeB' THEN 2
WHEN n2.Type='TypeC' THEN 3
END
There is a piece of information missing. You say:
Always join name of typeA only if exists. If not, join name of typeB. If neither exists join name of typeC.
But you do not indicate why you prefer typeA over typeB. This information is not included in your data.
In the answer of #fthiella, either lexicographical is assumed, or an arbitrary order is given using FIELD. This is also the reason why two joins with the table nnp_name is necessary.
You can solve this problem by adding a table name_type (id, name, order) and changing the type column to contain the id. This will allow you to add the missing information in a clean way.
With an additional join with this new table, you will be able get the preferred nnp_name for each row.

SQL Joining the correct username

Say I have the following tables
User
__________
id
username
email
FriendGame
__________
id
useroneid
usertwoid
status
I want to get games that the current user is part of, so I do this:
SELECT *
FROM FriendGame
WHERE useroneid=1663702020516206
OR usertwoid=1663702020516206
AND STATUS =1;
This is fine. Now I want to join the username, but only for the user that ISNT the supplied user (1663702020516206) since in FriendGame the given user exists EITHER as useroneid or usertwoid.
You can pretty much translate your logic directly into an on clause:
SELECT fg.*
FROM FriendGame fg JOIN
User u
ON (fg.useroneid = 1663702020516206 and fg.usertwoid = u.id) or
(fg.usertwoid = 1663702020516206 and fg.useroneid = u.id)
WHERE 1663702020516206 in (fg.useroneid, fg.usertwoid) AND
STATUS = 1;
Actually, the where clause is not necessary to get the right result set, but I think it makes the intention of the query clearer.

Sql Result IN a Query

dont blame for the database design.I am not its database architect. I am the one who has to use it in current situation
I hope this will be understandable.
I have 3 tables containing following data with no foreign key relationship b/w them:
groups
groupId groupName
1 Admin
2 Editor
3 Subscriber
preveleges
groupId roles
1 1,2
2 2,3
3 1
roles
roleId roleTitle
1 add
2 edit
Query:
SELECT roles
from groups
LEFT JOIN preveleges ON (groups.groupId=preveleges.groupId)
returns specific result i.e roles.
Problem: I wanted to show roleTitle instead of roles in the above query.
I am confused how to relate table roles with this query and returns required result
I know it is feasible with coding but i want in SQL.Any suggestion will be appreciated.
SELECT g.groupName,
GROUP_CONCAT(r.roleTitle
ORDER BY FIND_IN_SET(r.roleId, p.roles))
AS RoleTitles
FROM groups AS g
LEFT JOIN preveleges AS p
ON g.groupId = p.groupId
LEFT JOIN roles AS r
ON FIND_IN_SET(r.roleId, p.roles)
GROUP BY g.groupName ;
Tested at: SQL-FIDDLE
I would change the data structure it self. Since It's not normalised, there are multiple elements in a single column.
But it is possible with SQL, if for some (valid) reason you can't change the DB.
A simple "static" solution:
SELECT REPLACE(REPLACE(roles, '1', 'add'), '2', 'edit') from groups
LEFT JOIN preveleges ON(groups.groupId=preveleges.groupId)
A more complex but still ugly solution:
CREATE FUNCTION ReplaceRoleIDWithName (#StringIds VARCHAR(50))
RETURNS VARCHAR(50)
AS
BEGIN
DECLARE #RoleNames VARCHAR(50)
SET #RoleNames = #StringIds
SELECT #RoleNames = REPLACE(#RoleNames, CAST(RoleId AS VARCHAR(50)), roleTitle)
FROM roles
RETURN #RoleNames
END
And then use the function in the query
SELECT ReplaceRoleIDWithName(roles) from groups
LEFT JOIN preveleges ON(groups.groupId=preveleges.groupId)
It is possible without function, but this is more readable. Made without editor so it's not tested in anyway.
You also tagged the question with PostgreSQL and it's actually quite easy with Postgres to work around this broken design:
SELECT grp.groupname, r.roletitle
FROM groups grp
join (
select groupid, cast(regexp_split_to_table(roles, ',') as integer) as role_id
from privileges
) as privs on privs.groupid = grp.groupid
join roles r on r.roleid = privs.role_id;
SQLFiddle: http://sqlfiddle.com/#!12/5e87b/1
(Note that I changed the incorrectly spelled name preveleges to the correct spelling privileges)
But you should really, really re-design your data model!
Fixing your design also enables you to define foreign key constraints and validate the input. In your current model, the application would probably break (just as my query would), if someone inserted the value 'one,two,three' into the roles table.
Edit
To complete the picture, using Postgres's array handling the above could be slightly simplified using a similar approach as MySQL's find_in_set()
select grp.groupname, r.roletitle
from groups grp
join privileges privs on grp.groupid = privs.groupid
join roles r on r.roleid::text = any (string_to_array(privs.roles, ','))
In both cases if all role titles should be shown as a comma separated list, the string_agg() function could be used (which is equivalent to MySQL's group_concat()
select grp.groupname, string_agg(r.roletitle, ',')
from groups grp
join privileges privs on grp.groupid = privs.groupid
join roles r on r.roleid::text = any (string_to_array(privs.roles, ','))
group by grp.groupname

How do I copy multiple values from within the same table to other values in that same table in SQL?

First of all I'm rather new to SQL and so even though I believe a similar question was asked in this thread ( SQL Query - Copy Values in Same Table ) I literally can't understand it well enough to utilize the information. For that I apologize.
Now, I have a table that looks something like this:
company id | parameter name | parameter title
P | Parameter One | First Parameter
P | Parameter Two | Second Parameter
P | Parameter Three| Third Parameter
W | Parameter One | NULL
W | Parameter Two | NULL
Except that my table obviously has quite a lot of rows. I already went through filling in all the parameter titles where the company id was 'P' and would like to avoid manually doing the same for those with company id 'W'. My question is what SQL statement (this is in Microsoft SQL Server 2008) can I use to copy the values in the column "parameter title" where the company id is 'P' to the values in the same column where the company id is 'W' and both parameter names match up (W has less parameters than P)?
Using the previously linked thread I was able to come up with the following, but it spits out an error and I know it's not done correctly:
UPDATE COMP_PARAMETER_COPY
SET PARAM_TITLE=(SELECT PARAM_TITLE FROM COMP_PARAMETER_COPY P
WHERE P.COMP_ID = 'P' AND P.PARAM_TITLE=PARAM_TITLE)
WHERE COMP_ID='W'
(I'm playing around with a copy of the table instead of the actual table)
The error I get is "Msg 512, Level 16, State 1, Line 1
Subquery returned more than 1 value. This is not permitted when the subquery follows =, !=, <, <= , >, >= or when the subquery is used as an expression.
The statement has been terminated."
Thank you for your help and advice,
-Asaf
You need to ensure that your subquery is only returning one result. Right now that error message is telling you that you're getting more than one record returned.
UPDATE W
SET PARAM_TITLE = (
SELECT PARAM_TITLE FROM COMP_PARAMETER_COPY P
WHERE P.COMP_ID = 'P' AND P.PARAM_NAME = W.PARAM_NAME
)
FROM COMP_PARAMETER_COPY W
WHERE W.COMP_ID = 'W'
Try giving the above SQL a whirl. This could still give you more than one result, but without knowing what your table looks like and what the data constraints are it's hard to give you something guaranteed to work.
Try adding the DISTINCT keyword to your query:
UPDATE COMP_PARAMETER_COPY
SET PARAM_TITLE=(SELECT DISTINCT PARAM_TITLE FROM COMP_PARAMETER_COPY P
WHERE P.COMP_ID = 'P' AND P.PARAM_TITLE=PARAM_TITLE)
WHERE COMP_ID='W'