I want to choose from a list of strings and assign that as the value of one of the columns for my SELECT.
Something like the following:
SELECT id, name, GET_RANDOM_TYPE('Basic', 'Silver', 'Gold', 'Premium') AS type
FROM tbl
I'm just doing some tests hence why I need this.
Not terribly familiar with oracle, but perhaps you can simply use round(dbms_random.value(1,4)) in conjunction with a CASE expression:
SELECT id,
CASE round(dbms_random.value(1,4))
WHEN 1 THEN 'Basic'
WHEN 2 THEN 'Silver'
WHEN 3 THEN 'Gold'
WHEN 4 THEN 'Premium'
END AS type
FROM table
Create a table with your list of values that has a number as a primary key.
Then
Select your_text
from your_random_table
where ID = TRUNC(DBMS_RANDOM.value(1,10));
The statement above will give you any one 10 pseudo random numbers and assumes you have 10 random values in your table. It's not really random but works for testing. See here.
Related
I have a table, Ellipses (...), represent multiple columns of a similar type
TABLE: diagnosis_info
COLUMNS: visit_id,
patient_diagnosis_code_1 ...
patient_diagnosis_code_100 -- char(100) with a value of ‘0’ or ‘1’
How do I find the most common diagnosis_code? There are 101 columns including the visit_id. The table is like a matrix table of 0s and 1s. How do I write something that can dynamically account for all the columns and count all the rows where the value is 1?
What I would normally do is not feasable as there are too many columns:
SELECT COUNT(patient_diagnostic_code_1), COUNT(patient_diagnostic_code_2),... FROM diagnostic_info WHERE patient_diagnostic_code_1 = ‘1’ and patient_diagnostic_code_2 = ‘1’ and ….
Then even if I typed all that out how would I select which column had the highest count of values = 1. The table is more column oriented instead of row oriented.
Unfortunately your data design is bad from the start. Instead it could be as simple as:
patient_id, visit_id, diagnosis_code
where a patient with 1 dignostic code would have 1 row, a patient with 100 diagnostic codes 100 rows and vice versa. At any given time you could transpose this into the format you presented (what is called a pivot or cross tab). Also in some databases, for example postgreSQL, you could put all those diagnostic codes into an array field, then it would look like:
patient_id, visit_id, diagnosis_code (data type -bool or int- array)
Now you need the reverse of it which is called unpivot. On some databases like SQL server there is UNPIVOT as an example.
Without knowing what your backend this, you could do that with an ugly SQL like:
select code, pdc
from
(
select 1 as code, count(*) as pdc
from myTable where patient_diagnosis_code_1=1
union
select 2 as code, count(*) as pdc
from myTable where patient_diagnosis_code_2=1
union
...
select 100 as code, count(*) as pdc
from myTable where patient_diagnosis_code_100=1
) tmp
order by pdc desc, code;
PS: This would return all the codes with their frequency ordered from most to least. You could limit to get 1 to get the max (with ties in case there are more than one code to match the max).
How can I return a unique value based on a set of non unique values being searched?
For example:
If I wanted to return one phone number for a list of 4 people who can have more than one phone number - but I can only use one phone number for each person. It doesn't matter which phone number I use to reach them because any number that belongs to them will get me to them.
I don't think something like this exists - but if I could use something like the DISTINCT modifier except it would be called FIRST - it would solve my problem:
SELECT FIRST ID
FROM Sample_Table
WHERE ID in ("Bob", "Sam", "Kyle", "Jordan")
In picture - from this
I'd like that (or any) query to return
.
I'm using this type of query in a db where for 200 "ID"s there are millions of "Unique Values", so it is hard to get crafty.
EDIT The Unique value in my db has numbers and letters in each value
There is no such thing as a "first id" in a SQL table. Tables represent unordered sets. You can accomplish what you want (if I understand correctly) using aggregation:
SELECT ID, MIN(UniqueValue)
FROM Sample_Table
WHERE ID in ('Bob', 'Sam', 'Kyle', 'Jordan')
GROUP BY ID;
using group by and max method can help you:
select id
,uniquvalue
,max (typeofvalue)
from Sample_Table
group by
id
,uniquvalue
I've a table that has id_categoria field having comma separated value, e.g., 1,2,3,4,64,31,12,14, because a record can belong to multiple categories. If I want to select records that belongs to category 1, I have to run following SQL query
SELECT *
FROM cme_notizie
WHERE id_categoria LIKE '1%'
ORDER BY `id` ASC
and then select all records from the record set that have id_categoria exactly 1 in id_categoria. Let's assume that the value 1 does not exist, but column value like 12, 15, 120 ... still contains 1.
There is a way to take only 1? without taking derivatives or other?
As comments say, you probably shouldn't do that. Instead, you should have another table with one row per category. But if you decide to go with this inferior solution, you can do the following:
SELECT *
FROM cme_notizie
WHERE CONCAT(',', id_categoria, ',') LIKE '%,1,%'
ORDER BY id ASC
Okay, I probably could have come up with a better title, but wasn't sure how to word it so let me explain.
Say I have a table with the column 'CODE'. Each record in my table will have either 'A', 'B', or 'C' as it's value in the 'CODE' column. What I would like is to get a count of how many 'A's, 'B's, and 'C's I have.
I know I could accomplish this with 3 different queries, but I'm wondering if there is a way to do it with just 1.
Use:
SELECT t.code,
COUNT(*) AS numInstances
FROM YOUR_TABLE t
GROUP BY t.code
The output will resemble:
code numInstances
--------------------
A 3
B 5
C 1
If a code exists that has not been used, it will not show up. You'd need to LEFT JOIN to the table containing the list of codes in order to see those that don't have any references.
I wish to do a select on a table and order the results by a certain keyword or list of keywords. For example I have a table like so:
ID Code
1 Health
2 Freeze
3 Phone
4 Phone
5 Health
6 Hot
so rather than just do a simple Order By asc/desc I'd like to order by Health, Phone, Freeze, Hot. Is this possible?
Try using this:
select * from table
order by FIELD(Code, 'Health', 'Phone', 'Freeze', 'Hot')
Here's a horrible hack:
select * from table
order by (
case Code
when 'Health' then 0
when 'Phone' then 1
when 'Freeze' then 2
when 'Hot' then 3
end
)
You can join with the Keywords table, and include a sequence column, and ORDER BY Keyword.Sequence.
Example your keywords table looks like this:
ID Code Sequence
1 Health 1
2 Freeze 3
3 Phone 2
4 Hot 4
Then you can join.
SELECT *
FROM MyTable INNER JOIN
Keywords ON Keywords.ID = MyTable.KeywordID
ORDER BY Keywords.Sequence
Hope this gives you the idea.
Nowadays MySQL has a function called find_in_set()
Use it like this:
select * from table
order by find_in_set(Code,'Health','Phone','Freeze','Hot')
Is this just a one off ORDER BY or something that you're going to want to do often and on more values than specified here?
The order that you have given is arbitrary, therefore an identifier needs to be given to achieve what you want
SELECT
ID,
Code,
CASE Code
WHEN 'Health' THEN 1
WHEN 'Phone' THEN 2
WHEN 'Freeze' THEN 3
WHEN 'Hot' THEN 4
END As OrderBy
FROM Table
ORDER BY
OrderBy
Or
SELECT
ID,
Code
FROM Table
ORDER BY
CASE Code
WHEN 'Health' THEN 1
WHEN 'Phone' THEN 2
WHEN 'Freeze' THEN 3
WHEN 'Hot' THEN 4
END
(I'm not familiar with MySQL but the above would work in SQL Server. The syntax for MySQL won't be too different)
If you're likely to want to do this often, then create an OrderBy column on the table or create an OrderBy table with a FK link to this table and specify an OrderBy numerical field in that.
Hi this is a SQL Server query but I am sure you can do this in MySQL as well:
SELECT ID, Code
FROM x
ORDER BY
CASE Code WHEN 'Health' THEN 1
WHEN 'Phone' THEN 2
WHEN 'Freeze' THEN 4
WHEN 'Hot' THEN 5
ELSE 6 END ASC
, Code ASC
Couple options:
Add OrderCode column with numerical
desired order
Add a table with FK to this table ID
and OrderCode
Yes join your results to your code table and then order by code.CodeOrder
EDIT: Explaing the use of the code table...
Create a separate table of Codes (CodeId, Code, CodeOrder) and join to this and order by CodeOrder. This is nicer than doing the order by (case...) hack suggested since you can easily change the codes and the orders.