I have a table called cakes that contains the columns: id, title, description, keywords. I also have a table called keywords, with cakes being the parent. The keywords table contains two columns: id and keyword
I need two queries: UPDATED
If a person types in ingredients such as chocolate, hazelnut, strawberry (could be anything separated by a comma) I need the query to search for cakes that contain all three keywords and display results. Display ONLY cakes that contain all three. If no cake matches, I need a message saying nothing found.
I have a label on the search box which says, Find similar cakes. If a person types in Vanilla Raspberry or example, the query needs to locate the cake in the database and match its keywords to the keywords of other cakes and display results. Display ONLY cakes that have the same keywords.
Not sure how to write these queries. Any help is appreciated. Thanks!
If the database must use a delimited long-string field for "keywords" rather than putting them in rows, then you will want to use the LIKE Operator
Assuming your [keywords] column is formatted like this:
'chocolate,ganache,strawberry'
You can search for "similar" cakes like this:
SELECT
columns
FROM
table t
WHERE
t.[keywords] LIKE '%chocolate%'
OR t.[keywords] LIKE '%cheesecake%'
Though, if you can change the schema, I would do so. Searching normalized keyword rows will be much more efficient and fast than having the DB parse through text using LIKE
If you could make a keywords table, which references the parent table by ID, you could do an equality search using a JOIN which would be superior, in my opinion.
It might have three columns: Id, ParentId, Keyword
EDIT: So based on your update, you have a cakewords table which can be searched.
This is untested, and there is likely a more efficient way using no IN clause. But the idea is that you know all the keyword id's for your specific cake. Then you are looking for other cakes having keywords in that collection.
SELECT
columns
FROM
cake AS cs
JOIN
cakewords AS csw
ON csw.[cakeid] = cs.[id]
WHERE
csw.[wordid] IN
(SELECT
cw.[wordid]
FROM
cakewords AS cw
JOIN
cakes AS c
ON c.[id] = cw.[cakeid]
WHERE
c.[id] = #pMyCurrenctCakeId
(
EDIT2: Here is a good related question:
What's the optimal solution for tag/keyword matching?
Based on an answer within, you might try this:
SELECT DISTINCT
c.[id]
FROM
cakewords AS cw1
INNER JOIN cakewords cw2
ON cw2.[wordid] = cw1.[wordid]
INNER JOIN cake AS c
ON c.[id] = cw.[cakeid]
WHERE
cw1.[cakeid] = #current_cake_id
Related
I am trying to SELECT id, description, title FROM table1, table2, table100
Say I get this working, is it better for me to just combine all my tables in phpmyadmin?
The problem is I have around 100 tables all of different categories of books so I want to keep them seperated in their individual tables.
I am trying to make a search engine that searches all the books in the entire database. All tables have the same column names.
So really all I really am trying to do is search the entire database's tables for an id, description, title. My search works, just I can only search 1 table and every solution online I have found only really works efficiantly with 2 or 3 tables.
Thanks in advance.
The best is to redesign your database, everything into a single table with an additional "category" column.
in the meantime, you can create a view which union the tables with an additional column for the category.
I recommend redesign the model and unifique this 100 tables to 1, and add a new column with category but integer value, not string value. In this way, you can index the category column with the other fields (id, description, title) for speed up the query.
This resolution is more easy for avoid pain later.
I recommend keeping one table A with id, description, title, category and create another table B with categories. Table A has to have a foreign key with table categories. Then create a query to retrieve the books with a specific category.
Example:
SELECT id, description, title, category FROM books WHERE category = "drama"
I think it speaks to the database design itself as mentioned by most here. You've a few options depending on how much time you have on your hands:
(Short Term / Quick Fix) Central table with all your current fields plus category as a flag to differentiate between the current tables you have. So your insert will be something like "INSERT INTO newtable (ID,AssetID,ServiceID,Category) SELECT id, description, title, 'Fiction' FROM table1 ;"
If you tables are incrementally named like table1, table2 upto table100, you could then maybe write a quick php script that will iterate through the insert loop while incrementing on table on each iteration until the last table.
In the long run, you could invest in a json field that will house all your other data excluding keys that pertaining to a single entry
I have a table called cakes that contains the columns: id, title, description, keywords. I also have a table called keywords, with cakes being the parent. The keywords table contains two columns: id and keyword. I need to write the following two queries:
If a person types in ingredients such as chocolate, hazelnut, strawberry (could be any number of keywords separated by a comma) I need the query to search for cakes that contain ALL of the keywords and display results. Display ONLY cakes that contain all keywords. If no cake matches, I need a message saying nothing found.
I have a label on the search box which says, Find similar cakes. If a person types in Vanilla Raspberry or example, the query needs to locate the cake in the database and match its keywords to the keywords of other cakes and display results. Display ONLY cakes that have the same keywords and a MINIMUM of three keywords that are the same.
Not sure how to write these queries. Any help is appreciated. Thanks!
SELECT CakeID, CakeName
FROM TableName
WHERE IngredientName IN ('chocolate', 'hazelnut', 'strawberry' )
GROUP BY CakeID, CakeName
HAVING COUNT(*) = 3
or if uniqueness was not enforce on ingredients for every cakes, use DISTINCT
SELECT CakeID, CakeName
FROM TableName
WHERE IngredientName IN ('chocolate', 'hazelnut', 'strawberry' )
GROUP BY CakeID, CakeName
HAVING COUNT(DISTINCT IngredientName) = 3
SQL of Relational Division
I would like to select all matches from a commaseparated column in table2, where column could be like this: 0,1,2 OR 2,4,5 OR 2,5 OR 1,3,5 etc.
I have tried with:
SELECT * from table where 1,3,5 IN(SELECT commaseparated FROM table2) WHERE ..
But error on statement when using commas.
I've also tried using REGEXP but in my case i need to search for all matches within 1,3,5
How can i solve this one? :)
Can't do that in standard SQL. it's
WHERE singlevalue IN (list, of, values)
if you want to compare lists against lists, you should revamp your tables so they're properly normalized. Storing formatted data in a field basically negates the purpose of having a relational database - you can't establish relationships with the data if it's not in a format that allows relationships to be formed.
If those CSV lists were in sub-tables, you could do a very simple JOIN query to meet your specifications.
I have a programme listing database with all the information needed for one programme packed into one table (I should have split programmes and episodes into their own) Now since there are multiple episodes for any given show I wish to display the main page with just the title names in ascending and chosen letter. Now I know how to do the basic query but this is all i know
SELECT DISTINCT title FROM programme_table WHERE title LIKE '$letter%'
I know that works i use it. But I am using a dynamic image loading that requires a series number to return that image full so how do I get the title to be distinct but also load the series number from that title?
I hope I have been clear.
Thanks for any help
Paul
You can substitute the DISTINCT keyword for a GROUP BY clause.
SELECT
title
, series_number
FROM
programme_table
WHERE title LIKE '$letter%'
GROUP BY
title
, series_number
There are currently two other valid options:
The option suggested by Mohammad is to use a HAVING clause in stead of the WHERE clause this is actually less optimal:
The WHERE clause is used to restrict records, and is also used by the query optimizer to determine which indexes and tables to use. HAVING is a "filter" on the final result set, and is applied after ORDER BY and GROUP BY, so MySQL cannot use it to optimize the query.
So HAVING is a lot less optimal and you should only use it when you cannot use 'WHERE' to get your results.
quosoo points out that the DISTINCT keyword is valid for all listed columns in the query. This is true, but generally people do not recommend it (there is no performance difference *In some specific cases there is a performance difference***)**. The MySQL optimizer however spits out the same query for both so there is no actual performance difference.
Update
Although MySQL does apply the same optimization to both queries, there is actually a difference: when DISTINCT is used in combination with a LIMIT clause, MySQL stops as soon as it finds enough unique rows. so
SELECT DISTINCT
title
, series_number
FROM
programme_table
WHERE
title LIKE '$letter%'
is actually the best option.
select title,series_number from programme_table group by title,series_number having title like '$letter%';
DISTINCT keyword works actually for a list of colums so if you just add the series to your query it should return a set of unique title, series combinations:
SELECT DISTINCT title, series FROM programme_table WHERE title LIKE '$letter%'
Hey thanks for that but i have about 1000 entries with the same series so it would single out the series as well rendering about 999 programmes useless and donot show.
I however found out away to make it unique and show the series number
SELECT * FROM four a INNER JOIN (SELECT title, MIN(series) AS MinPid FROM four WHERE title LIKE '$letter%' GROUP BY title) b ON a.title = b.title AND a.series = b.MinPid
Hopefully it helps anyone in the future and thank you for the replies :)
I want to make a search engine in an intranet. Now i use this clause in PHP.
$k = explode(" ",$_GET[key]);
$sql = "select entreprise.*, employee.* where entreprise.* or employee.* like '%$k[0]%' or '%$k[1]%'";
But it seems doesn't work. Do you know where is wrong?
Thanks in advance.
Edit:
$sql = "select * from entreprise, site, salarie where entreprise.*, site.*, salarie.* like '%$k[0]%' or '%$k[1]%'";
I have modified the query clause. With this code, i think you can know what i want to do.
I want to find anything that matches the content in all the columns of entreprise table and the content in all the columns of employee table.
It's hard to exactly see what you're trying to do, but you need, in your SQL query, to specify :
on which tables you are working, with a from clause
on which fields the search has to be done, in the where clause.
how the data between employees and enterprises are related :
do you want to search for entreprises and their employees ?
for employees and there enterprises ?
for all enterprises and the employees when the employee or the enterprise contains the words ?
You could use something like this to search for entreprises that contain the word, and get their employees to :
select *
from entreprise
inner join employee on employee.id_entreprise = entreprise.id
where entreprise.name like '%word%'
or entreprise.description like '%word%';
Or, to search for employees that match the criteria and get their entreprise too :
select *
from employee
inner join entreprise on entreprise.id = employee.id_entreprise
where employee.name like '%word%';
(just some ideas -- you'll have to build from there !)
This:
$sql = "select entreprise.*, employee.* where entreprise.* or employee.* like '%$k[0]%' or '%$k[1]%'";
is not valid SQL. It is hard to guess what you want to do, but I'm trying anyway: you want to find employees, and search them by name or by enterprise that employs them. Is that the case? Or do you want to search employess and/or enterprises?
EDIT
I want to find anything that matches the content in all the columns of entreprise table and the content in all the columns of employee table.
Ok, first of all you should realize that SQL is probably not the best tool for this job. See the other commenter - his suggestions about sphinx and friends are good. But still, if you really want to:
$sql = '
SELECT e.id, e.name
FROM enterprise e
-- first, look in column1
WHERE e.column1 LIKE '."'%".$k[0]."%'".'
OR e.column1 LIKE '."'%".$k[1]."%'".'
...etc for all entries in k...
OR e.column1 LIKE '."'%".$k[N]."%'".'
-- then, look in column2
OR e.column2 LIKE '."'%".$k[0]."%'".'
OR e.column2 LIKE '."'%".$k[1]."%'".'
...and so on and so forth for all entries in $k and all columns in enterprise...
UNION ALL
SELECT s.id, s.name
FROM salarie s
WHERE ...and the same for columns of salarie...
...
UNION ALL
...any other tables you want to search...
';
As you can see, not something that makes you happy.
Another approach that might give you more joy is having some overnight job to scan all rows in the tables you're interested in, parse the texts you want to search into separate words, and store those in a keyword table, and storing the association between an object from the source database and the keyword in a separate table. You can then search the keyword table and use the id's and table names you find for a collection of keywords to build the actual query to retrieve those rows. This is what I do, and it works great. It works better because there is a relatively small amount of words that you will encounter, whereas the collection of objects is quite possible very large.