I can add virtual columns as
SELECT '1' as id
| id |
-------
| 1 |
But I want add multiple values, example:
SELECT ('1','2','3') as id
| id |
-------
| 1 |
| 2 |
| 3 |
But this don't work
Like Marc B said in a comment you can't have a single query split a single row into multiple rows, but you can have multiple queries, each producing one of the values, by chaining them together with union.
SELECT 1 id
UNION
SELECT 2
UNION
SELECT 3
As the answer was provided in a couple of comments I'll post it as a community wiki.
Related
This question already has answers here:
SQL select only rows with max value on a column [duplicate]
(27 answers)
Closed 4 years ago.
I'm currently trying to select unique entries in only the name column. I have tried using this query but it will not return prices that are the same as well. I've tried other variations with no success either.
SELECT DISTINCT name, price from table;
Here's the table I'm working with:
+----+-------------------+
| id | name | price |
+----+-----------+-------+
| 1 | Henry | 20 |
| 2 | Henry | 30 |
| 3 | Robert | 20 |
| 4 | Joshua | 10 |
| 5 | Alexander | 30 |
+----+-----------+-------+
The output that I'm seeking is:
+----+-------------------+
| id | name | price |
+----+-----------+-------+
| 1 | Henry | 20 |
| 3 | Robert | 20 |
| 4 | Joshua | 10 |
| 5 | Alexander | 30 |
+----+-----------+-------+
The desired output as you can tell only removed the duplicate name and none of the prices. Is there something I can add to my query above to only select unique entries in the name column? Any help is really appreciated as I have tried to find a solution on here, Google, DuckDuckGo, etc. with no luck.
From your sample data, this should work.
SELECT MIN(Id) AS Id, name, MIN(price) AS price
FROM table
GROUP BY name;
This is what GROUP BY is for:
SELECT * FROM `table` GROUP BY `name`
Usually people run into trouble because they will now get an arbitrarily-chosen row when more than one matches for a given name — you have to use aggregate functions to pick a specific one, e.g. "the one with the maximum price".
But in your case, since you don't seem to care which row is returned, this is perfect as-is.
So you want to select distinct list of rows AND then select that given entire row from the table? Try this query where temporary query is just a list of uniqueid then that row is linked back to the table.
Select n.*
From nameprices n
Join (Select MIN(id) as id
From nameprices
Group by name
Order By id) aTemp On (aTemp.id=n.id);
This is a common problem in SQL queries where we want to use that given fully row data but filter was using a distinct/groupby formula.
I have an MySQL table creatures:
id | name | base_hp | quantity
--------------------------------
1 | goblin | 5 | 2
2 | elf | 10 | 1
And I want to create creature_instances based on it:
id | name | actual_hp
------------------------
1 | goblin | 5
2 | goblin | 5
3 | elf | 10
The ids of creatures_instances are not important and not relevant to creatures.ids.
How can I make it with just the MySQL in the most optimal (in terms of execution time) way? The single query would be best, but procedure is ok too. I use InnoDB.
I know that with a help of e.g. php I could:
select each row separately,
make for($i=0; $i<line->quantity; $i++) loop in which I insert one row to creatures_instances for each iteration.
The most efficient way is to do everything in SQL. It helps if you have a numbers table. Without one, you can generate the numbers in a subquery. The following works up to 4 copies:
insert into creatures_instances(id, name, actual_hp)
select id, name, base_hp
from creatures c join
(select 1 as n union all select 2 union all select 3 union all select 4
) n
on n.n <= c.quantity;
I have a MySQL table like below:
| ID | userIDs
---------------
| 1 | 4,3,5
| 2 | 2,3
| 3 | 1,2,3
I want to retrieve all the rows in which userIDs doesn't contain 1.
I tried
SELECT * FROM tablename WHERE 1 NOT IN (userIDs)
But it's not working.
Use FIND_IN_SET
SELECT * FROM tablename
WHERE find_in_set(1, userIDs) = 0
But actually you should rather change your table design. Never store multiple values in a single column!
I have two tables
one as td_job which has these structure
|---------|-----------|---------------|----------------|
| job_id | job_title | job_skill | job_desc |
|------------------------------------------------------|
| 1 | Job 1 | 1,2 | |
|------------------------------------------------------|
| 2 | Job 2 | 1,3 | |
|------------------------------------------------------|
The other Table is td_skill which is this one
|---------|-----------|--------------|
|skill_id |skill_title| skill_slug |
|---------------------|--------------|
| 1 | PHP | 1-PHP |
|---------------------|--------------|
| 2 | JQuery | 2-JQuery |
|---------------------|--------------|
now the job_skill in td_job is actualy the list of skill_id from td_skill
that means the job_id 1 has two skills associated with it, skill_id 1 and skill_id 2
Now I am writing a query which is this one
SELECT * FROM td_job,td_skill
WHERE td_skill.skill_id IN (SELECT td_job.job_skill FROM td_job)
AND td_skill.skill_slug LIKE '%$job_param%'
Now when the $job_param is PHP it returns one row, but if $job_param is JQuery it returns empty row.
I want to know where is the error.
The error is that you are storing a list of id's in a column rather than in an association/junction table. You should have another table, JobSkills with one row per job/skill combination.
The second and third problems are that you don't seem to understand how joins work nor how in with a subquery works. In any case, the query that you seem to want is more like:
SELECT *
FROM td_job j join
td_skill s
on find_in_set(s.skill_id, j.job_skill) > 0 and
s.skill_slug LIKE '%$job_param%';
Very bad database design. You should fix that if you can.
Hey all, I am looking for a way to query my database table only once in order to add an item and also to check what last item count was so that i can use the next number.
strSQL = "SELECT * FROM productr"
After that code above, i add a few product values to a record like so:
ID | Product | Price | Description | Qty | DateSold | gcCode
--------------------------------------------------------------------------
5 | The Name 1 | 5.22 | Description 1 | 2 | 09/15/10 | na
6 | The Name 2 | 15.55 | Description 2 | 1 | 09/15/10 | 05648755
7 | The Name 3 | 1.10 | Description 3 | 1 | 09/15/10 | na
8 | The Name 4 | 0.24 | Description 4 | 21 | 09/15/10 | 658140
i need to count how many times it sees gcCode <> 'na' so that i can add a 1 so it will be unique. Currently i do not know how to do this without opening another database inside this one and doing something like this:
strSQL2 = "SELECT COUNT(gcCode) as gcCount FROM productr WHERE gcCode <> 'na'
But like i said above, i do not want to have to open another database query just to get a count.
Any help would be great! Thanks! :o)
There's no need to do everything in one query. If you're using InnoDB as a storage engine, you could wrap your COUNT query and your INSERT command in a single transaction to guarantee atomicity.
In addition, you should probably use NULL instead of na for fields with unknown or missing values.
They're two queries; one is a subset of the other which means getting what you want in a single query will be a hack I don't recommend:
SELECT p.*,
(SELECT COUNT(*)
FROM PRODUCTR
WHERE gccode != 'na') AS gcCount
FROM PRODUCTR p
This will return all the rows, as it did previously. But it will include an additional column, repeating the gcCount value for every row returned. It works, but it's redundant data...