I have a table like this
d_id | d_name | d_desc | sid
1 |flu | .... |4,13,19
Where sid is VARCHAR. What i want to do is when enter 4 or 13 or 19, it will display flu. However my query only works when user select all those value. Here is my query
SELECT * FROM diseases where sid LIKE '%sid1++%'
From above query, I work with PHP and use for loop to put the sid value inside LIKE value. So there I just put sid++ to keep it simple. My query only works when all of the value is present. If let say user select 4 and 19 which will be '%4,19%' then it display nothing. Thanks all.
If you must do what you ask for, you can try to use FIND_IN_SET().
SELECT d_id, d_name, d_description
FROM diseases
WHERE FIND_IN_SET(13,sid)<>0
But this query will not be sargable, so it will be outrageously slow if your table contains more than a few dozen rows. And the ICD10 list of disease codes contains almost 92,000 rows. You don't want your patient to die or get well before you finish looking up her disease. :-)
So, you should create a separate table. Let's call it diseases_sid.
It will contain two columns. For your example the contents will be
d_id sid
1 4
1 13
1 19
If you want to find a row from your diseases table by sid, do this.
SELECT d.d_id, d.d_name, d.d_description
FROM diseases d
JOIN diseases_sid ds ON d.d_id = ds.d_id
WHERE ds.sid = 13
That's what my colleagues are talking about in the comments when they mention normalization.
Related
I have a small problem with a php mysql query, I am looking for help.
I have a family tree table, where I am storing for each person his/her ancestors id separated by a comma. like so
id ancestors
10 1,3,4,5
So the person of id 10 is fathered by id 5 who is fathered by id 4 who is fathered by 3 etc...
Now I wish to select all the people who have id x in their ancestors, so the query will be something like:
select * from people where ancestors like '%x%'
Now this would work fine except, if id x is lets say 2, and a record has an ancestor id 32, this like query will retrieve 32 because 32 contains 2. And if I use '%,x,%' (include commas) the query will ignore the records whose ancestor x is on either edge(left or right) of the column. It will also ignore the records whose x is the only ancestor since no commas are present.
So in short, I need a like query that looks up an expression that either is surrounded by commas or not surrounded by anything. Or a query that gets the regular expression provided that no numbers are around. And I need it as efficient as possible (I suck at writing regular expressions)
Thank you.
Edit: Okay guys, help me come up with a better schema.
You are not storing your data in a proper way. Anyway, if you still want to use this schema you should use FIND_IN_SET instead of LIKE to avoid undesired results.
SELECT *
FROM mytable
WHERE FIND_IN_SET(2, ancestors) <> 0
You should consider redesigning your database structure. Add new table "ancestors" to database with columns:
id id_person ancestor
1 10 1
2 10 3
3 10 4
After -- use JOIN query with "WHERE IN" to choose right rows.
You're having this issue because of wrong design of database.First DBMS based db's aren't meant for this kind of data,graph based db's are more likely to fit for this kind of solution.
if it contain small amount of data you could use mysql but still the design is still wrong,if you only care about their 'father' then just add a column to person (or what ever you call it) table. if its null - has no father/unknown otherwise - contains (int) of his parent.
In case you need more then just 'father' relationship you could use a pivot table to contain two persons relationship but thats not a simple task to do.
There are a few established ways of storing hierarchical data in RDBMS. I've found this slideshow to be very helpful in the past:
Models for Hierarchical Design
Since the data deals with ancestry - and therefore you wouldn't expect it to change that often - a closure table could fit the bill.
Whatever model you choose, be sure to look around and see if someone else has already implemented it.
You could store your values as a JSON Array
id | ancestors
10 | {"1","3","4","5"}
and then query as follows:
$query = 'select * from people where ancestors like \'%"x"%\'';
Better is of course using a mapping table for your many-to-many relation
You can do this with regexp:
SELECT * FROM mytable WHERE name REGEXP ',?(x),?'
where x is your searched value
DROP TABLE IF EXISTS my_table;
CREATE TABLE my_table
(id INT NOT NULL AUTO_INCREMENT PRIMARY KEY
,ancestors VARCHAR(250) NOT NULL
);
INSERT INTO my_table VALUES(10,',1,3,4,5');
SELECT *
FROM my_table
WHERE CONCAT(ancestors,',') LIKE '%,5,%';
+----+-----------+
| id | ancestors |
+----+-----------+
| 10 | ,1,3,4,5 |
+----+-----------+
SELECT *
FROM my_table
WHERE CONCAT(ancestors,',') LIKE '%,4,%';
+----+-----------+
| id | ancestors |
+----+-----------+
| 10 | ,1,3,4,5 |
+----+-----------+
Trying to write statement where in single statement select all (*) and sum one column from the same database and the same table, depending on conditions.
Wrote such statement (based on this Multiple select statements in Single query)
SELECT ( SELECT SUM(Amount) FROM 2_1_journal), ( SELECT * FROM 2_1_journal WHERE TransactionPartnerName = ? )
I understand that SELECT SUM(Amount) FROM 2_1_journal will sum all values in column Amount (not based on codition).
But at first want to understand what is correct statement
With above statement get error SQLSTATE[21000]: Cardinality violation: 1241 Operand should contain 1 column(s)
Can not understand error message. From advice here MySQL - Operand should contain 1 column(s) understand that subquery SELECT * FROM 2_1_journal WHERE TransactionPartnerName = ? must select only one column?
Tried to change statement to this SELECT ( SELECT * FROM 2_1_journal WHERE TransactionPartnerName = ? ), ( SELECT SUM(Amount) FROM 2_1_journal), but get the same error...
What would be correct statement?
SELECT *, (SELECT SUM(Amount) FROM 2_1_journal)
FROM 2_1_journal
WHERE TransactionPartnerName = ?
This selects sums up Amount from the entire table and "appends" all rows where TransactionPartnerName is the parameter you bind in the client code.
If you want to limit the sum to the same criteria as the rows you select, just include it:
SELECT *, (SELECT SUM(Amount) FROM 2_1_journal WHERE TransactionPartnerName = ?)
FROM 2_1_journal
WHERE TransactionPartnerName = ?
A whole different thing: table names like 2_1_journal are strong indicators of a broken database design. If you can redo it, you should look into how to normalize the database properly. It is most likely pay back many times over.
With regard to normalization (added later):
Since the current design uses keys in table names (such as the 2 and 1 in 2_1_journal), I'll quickly illustrate how I think you can vastly improve that design. Lets say that the table 2_1_journal has the following data (I'm just guessing here because the tables haven't been described anywhere yet):
title | posted | content
------+------------+-----------------
Yes! | 2013-01-01 | This is just a test
2nd | 2013-01-02 | Another test
This stuff belongs to user 2 in company 1. But hey! If you look at the rows, the fact that this data belongs to user 2 in company 1 is nowhere to be found.
The problem is that this design violates one of the most basic principles of database design: don't use keys in object (here: table) names. A clear indication that something is very wrong is if you have to create new tables if something new is added. In this case, adding a new user or a new company requires adding new tables.
This issue is easilly fixed. Create one table named journal. Next, use the same columns, but add another two:
company | user | title | posted | content
--------+------+-------+------------+-----------------
1 | 2 | Yes! | 2013-01-01 | This is just a test
1 | 2 | 2nd | 2013-01-02 | Another test
Doing it like this means:
You never add or modify tables unless the application changes.
Doing joins across companies or users (and anything else that used to be part of the table naming scheme is now possible with a single, fairly simple select statement).
Enforcing integrity is easy - if you upgrade the application and want to change the tables, the changes doesn't have to be repeated for each company and user. More importantly, this lowers the risk of having the application get out of sync with the tables in the database (such as adding the field comments to all x_y_journal tables, but forgetting 5313_4324_journal causing the application to break only when user 5313 logs in. This is the kind of problem you don't want to deal with.
I am not writing this because it is a matter of personal taste. Databases are just designed to handle tables that are laid out as I describe above. The design where you use object keys as part of table names has a host of other problems associated with it that are very hard to deal with.
This is an example of my table:
|..id.|.class...|.group....|..name....|
|..5..|....1....|.....A....|....XX....|
|.19..|....1....|.....B....|....XX....|
|.12..|....2....|.....A....|....XX....|
|.28..|....2....|.....B....|....XX....|
|..8..|....3....|.....A....|....XX....|
|.50..|....3....|.....B....|....XX....|
It has about 30 rows per class and group. What I'm trying to do is to fetch all data after the row | 12 | 2 | A | XX |. Can't just state "where class > 2" since there are still some rows with class and group 2A that I need to be in the select.
Is there a way to do that, from SELECT or maybe a Fetch() argument in PHP & Mysql
Thanks!
Try this:
SELECT * FROM `table`
WHERE
CONCAT(`CLASS`, `GROUP`, `NAME`) >= '2AMarcus'
Select all ids and loop through them creating a comma-delimited list in PHP of the ids after 12 is found. Then do your select where id in ().
Or
Create the list of ids to exclude until 12 is found. Then do select where id not in ().
It looks like you need some work on normalizing tables, out of sql sentences.
If you need the rows after Class 2 Group A Name Marcus, it says to me that something occur in real life from that point in the time, an event, so, i would add a new column for timestamp or for another data for that event, and then back to sql sentences and use that new column for the apropiate SELECT / WHERE.
I am quite new to PHP and MySQL, but have experience of VBA and C++. In short, I am trying to count the occurrences of a value (text string), which can appear in 11 columns in my table.
I think I will need to populate a single-dimensional array from this table, but the table has 14 columns (named 'player1' to 'player14'). I want each of these 'players' to be entered into the one-dimensional array (if not NULL), before proceeding to the next row.
I know there is the SELECT DISTINCT statement in MySQL, but can I use this to count distinct occurrences across 14 columns?
For background, I am building a football results database, where player1 to player14 are the starting 11 (and 3 subs), and my PHP code will count the number of times a player has made an appearance.
Thanks for all your help!
Matt.
Rethink your database schema. Try this:
Table players:
player_id
name
Table games:
game_id
Table appearances:
appearance_id
player_id
game_id
This reduces the amount of duplicate data. Read up on normalization. It allows you to do a simple select count(*) from appearances inner join players on player_id where name='Joe Schmoe'
First of all, the database schema you're using is terrible, and you just found out a reason why.
That being said, I see no other way then to first get a list of all players by distinctly selecting the names of players into an array. Before each insertion, you would have to check if the name is already in the array (if it is already in, don't add it again).
Then, when you have the list of names, you would have to run an SQL statement for each player, adding up the number of occurences, like so:
SELECT COUNT(*)
FROM <Table>
WHERE player1=? OR player2=? OR player3=? OR ... OR player14 = ?
That is all pretty complicated, and as I said, you should really change your database schema.
This sounds like a job for fetch_assoc (http://php.net/manual/de/mysqli-result.fetch-assoc.php).
If you use mysqli, you would get each row as an associative array.
On the other hand the table design seems a bit flawed, as suggested before.
If you had on table team with team name and what not and one table player with player names.
TEAM
| id | name | founded | foo |
PLAYER
| id | team_id | name | bar |
With that structure you could add 14 players, which point at the same team and by joining the two tables, extract the players that match your search.
I have a MySQL query that results in something like this:
person | some_info
==================
bob | pphsmbf24
bob | rz72nixdy
bob | rbqqarywk
john | kif9adxxn
john | 77tp431p4
john | hx4t0e76j
john | 4yiomqv4i
alex | n25pz8z83
alex | orq9w7c24
alex | beuz1p133
etc...
(This is just a simplified example. In reality there are about 5000 rows in my results).
What I need to do is go through each person in the list (bob, john, alex, etc...) and pull out a row from their set of results. The row I pull out is sort of random but sort of also based on a loose set of conditions. It's not really important to specify the conditions here so I'll just say it's a random row for the example.
Anyways, using PHP, this solution is pretty simple. I make my query and get 5000 rows back and iterate through them pulling out my random row for each person. Easy.
However, I'm wondering if it's possible to get what I would from only a MySQL query so that I don't have to use PHP to iterate through the results and pull out my random rows.
I have a feeling it might involve a BUNCH of subselects, like one for each person, in which case that solution would be more time, resource and bandwidth intensive than my current solution.
Is there a clever query that can accomplish this all in one command?
Here is an SQLFiddle that you can play with.
To get a random value for a distinct name use
SELECT r.name,
(SELECT r1.some_info FROM test AS r1 WHERE r.name=r1.name ORDER BY rand() LIMIT 1) AS 'some_info'
FROM test AS r
GROUP BY r.name ;
Put this query as it stands in your sqlfiddle and it will work
Im using r and r1 as table alias names. This will also use a subquery to select a random some_info for the name
SQL Fiddle is here
My first response would be to use php to generate a random number:
$randId = rand($min, $max);
Then run a SQL query that only gets the record where your index equals $randID.
Here is the solution:
select person, acting from personel where id in (
select lim from
(select count(person) c, min(id) i, cast(rand()*(count(person)-1) +min(id)
as unsigned) lim from personel group by person order by i) t1
)
The table used in the example is below:
create table personel (
id int(11) not null auto_increment,
person char(16),
acting char(19),
primary key(id)
);
insert into personel (person,acting) values
('john','abd'),('john','aabd'),('john','adbd'),('john','abfd'),
('alex','ab2d'),('alex','abd3'),('alex','ab4d'),('alex','a6bd'),
('max','ab2d'),('max','abd3'),('max','ab4d'),('max','a6bd'),
('jimmy','ab2d'),('jimmy','abd3'),('jimmy','ab4d'),('jimmy','a6bd');
You can limit the number of queries, and order by "rand()" to get your desired result.
Perhaps if you tried something like this:
SELECT name, some_info
FROM test
WHERE name = 'tara'
ORDER BY rand()
LIMIT 1