There are 3 tables. Products, Options and Prod_Opts_relations. The latter holds product_id and option_id so i should be able to figure out which options are selected for any given product.
Now i want to retrieve all options from the options table where the value of an extra alias field should hold checked or unchecked depending on the existance of a mathing record in the relations table for a give product id.
Thus far i came up with this:
SELECT
IF(IN(SELECT id_option FROM prod_opt_relations WHERE id_product='18'),'y','n') AS booh
,optionstable.id AS parent_id
,optionstable.name_en AS parent_english
,optionstable.name_es AS parent_spanish
FROM product_options AS optionstable
WHERE 1
resulting in syntax errors.
Alas i just cannot figure out where things go wrong here
Use a left join between your two tables to retrieve all the data from the option table whenever there is a match or not. Then test if the value return from the right table is null to set your y/n flag.
SELECT
IF(por.id_product IS NULL, 'n', 'y') AS booh
,optionstable.id AS parent_id
,optionstable.name_en AS parent_english
,optionstable.name_es AS parent_spanish
FROM
product_options AS optionstable
LEFT JOIN prod_opt_relations as por ON (
por.id_product=18 AND por.id_option=optionstable.id_option
)
WHERE 1
You did not specify which expression should be compared to your IN-list:
IF( foo IN (...), 'y', 'n')
edit: Your statement lacks an equivalent to what is foo in this example.
See http://dev.mysql.com/doc/refman/5.0/en/comparison-operators.html#function_in
Related
I have four tables for a form-builder in my databse.
fields (fieldID(PK), typeID, fieldName, ...) - This table is a row by row list of all fields to be in the form
fields_types (typeID(PK), htmlType, ...) - This is a table that links fields to html types (and other settings)
fields_meta (FieldMetaID(PK), FieldID, mName, mValue) - Additional settings for fields, but more specific. A textarea field might have a height attribute, but almost no other field would use that.
fields_tyeps_meta (TypeMetaID(PK), typeID, tmName, tmValue) - Defines what extraneous settings a field can have, and also supplies default values if it's not explicitly set)
So my Query currently looks something like this
SELECT *
FROM Fields F
JOIN Field_Types FT
on FT.FieldID = F.FieldID
LEFT
JOIN Field_Meta FM
on FM.FieldID = F.FieldID
I was wondering if there's a way to join Fields_Types_Meta so that when the row's JOIN to Fields_Meta doesn't return a row (no mValue), it returns tmValue
I realize I can use something like (CASE WHEN mValue = "" THEN tmValue ELSE mValue END) AS UseValue, but I might have fields where I want to allow the value to be set to empty.
Edit: I could probably do something with a subquery and COUNT, using a CASE decision based on that. It might not be the healthiest performance-wise, but this query runs and caches itself til server restart, or until it's told to run again (updates to form design)
It looks like you just want ¢oalesce():
coalesce(FM.mValue, FT.tmValue) as UseValue
When FM.mValue is null, coalesce() returns FT.tmValue instead.
If you have null values in FM that you want to preserve in the result set, then use a case expression instead:
case when FM.FieldID IS NULL THEN FT.tmValue ELSE FM.mValue END as UseValue
This phrases as: when the left join did find a match in FM, use mValue from that row (even if it is null), else use FT.tmValue.
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.
From PHP Code $Lines is defined as a list of accessions e.g. 123,146,165,1546,455,155
plant table has sequential records with the highest idPlant (unique identifier) of say 1000.
My simple SQL Query:
SELECT * FROM plant WHERE `plant`.idPlant IN($Lines) order by plant.idPlant;
This brings back row data for '123,146,165' etc.
Is there away to be told that '1546' was not found? (and thus the user probably entered a typo, I can not use a 'confirm all numbers are below X' because in the real data the idPlant may not be sequential and the upper bound will increase during use).
Update:
Looking to get an output that will tell me what Numbers were not found.
You can build up a sub query using unions that returns a list of all your values, then LEFT JOIN against that, checking for NULL in the WHERE clause to find the non matching values.
Basic php for this would be something like this:-
<?php
$sub_array = explode(',', $Lines);
$sub = '(SELECT '.implode(' AS i UNION SELECT ', $sub_array).' AS i) sub0';
$sql = "SELECT sub0.i
FROM $sub
LEFT OUTER JOIN plant
ON plant.idPlant = sub0.i
WHERE plant.idPlant IS NULL";
?>
You can create a temporary table and compare it to the original table. It goes something like this:
CREATE TEMPORARY TABLE IF NOT EXISTS plantIDs (
ID INT(11) NOT NULL UNIQUE,
found INT(11) NOT NULL);
INSERT INTO plantIDs(ID) VALUES (123),(146),(165),(1546),(455),(155);
SELECT plantIDs.ID, COALESCE(plant.name, "Not Found") as PlantName, plant.* FROM plant RIGHT JOIN plantIDs ON plant.idPlant=plantIDs.ID ORDER BY plantIDs.ID;
Assuming you have a field named name inside the table plant, this code will produce a row for each plant and the column named PlantName will contain the name of hte plant or the text "Not Found", ofc you can change the coalesce value to anything that fits your needs.
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
I got the following sql question that I that won´t work for me. I know that the last CASE row are wrong but I would like to use a CASE statement like that in my where clause.
Short description of my situation:
I got several companies that got there own material linked to them with "companyID". Each material might be linked to a row in pricelist_entries. If I search for one row in the pricelist_entries table that is linked to many material rows all rows will be returned but I just want to return the one that belongs to the current company (the company that performs the search).
Conclusion: If materialID NOT NULL THEN materials.company="current.companyID".
SELECT peID, peName, materialID
FROM pricelist_entries
INNER JOIN pricelist ON pricelist_entries.peParentID=pricelist.pID
LEFT JOIN materials ON pricelist_entries.peID=materials.pricelist_entries_id
WHERE peBrand = 'Kama' AND pricelist.pCurrent = 1
AND (peName LIKE '%gocamp de%' OR peArtnr LIKE '%gocamp de%')
AND pricelist.country=0 AND pricelist_entries.peDeleted=0
CASE materialID WHEN IS NOT NULL THEN materials.companyID=10 END
Please tell me if I need to describe my problem in a better way.
Thanks in advance!
Sounds like just moving the condition into the join would make it simpler;
SELECT peID, peName, materialID
FROM pricelist_entries
INNER JOIN pricelist
ON pricelist_entries.peParentID=pricelist.pID
LEFT JOIN materials
ON pricelist_entries.peID=materials.pricelist_entries_id
AND materials.companyID=10 -- << condition
WHERE peBrand = 'Kama' AND pricelist.pCurrent = 1
AND (peName LIKE '%gocamp de%' OR peArtnr LIKE '%gocamp de%')
AND pricelist.country=0 AND pricelist_entries.peDeleted=0
It will only left join in material rows that are linked to the correct company.
You can't use CASE in the where clause that I'm aware of, you need to use it in the SELECT portion, but it will have the same effect. Something like this should work:
SELECT CASE materialid WHEN IS NOT NULL THEN companyid END as thiscompanyid
This will give you a new column named thiscompanyid and you can query off of that to get what you need.