SQL search for string within string - php

I want to create a search function on my site that will return strings within strings. For example: if there was a record in the SQL database where a column's value was "My name is Harry Potter", then the user could search for "Harry P" or "ott" or "My Name", and the record would come up in the search results.


use this in your SQL:
SELECT * FROM `table` WHERE title LIKE '%$search_word%'


select * from your_table
where instr(some_column, 'string_to_search') > 0


Use LIKE function.
SELECT * FROM myTable WHERE myName LIKE '%Harry P%'
SELECT * FROM myTable WHERE myName LIKE '%ott%'
SELECT * FROM myTable WHERE myName LIKE '%My Name%'
Here I have assume myName is the field name that you have in your database & myTable is the table name.
In PHP, your query should be
SELECT * FROM myTable WHERE myName LIKE '%$yourWord%'


If the table is / will be small, then a statement with LIKE '%word%' will be fine.
Although you might be tempted to use a MyISAM table to be able to use a Fulltext index, this is possible in InnoDB too. It will be a bit harder to implement it this way, but it will combine the high-performance text searching that MyISAM offers with all the benefits of InnoDB (transactions, row-level locking etc.).

Related

select data where %column% like $variable

I have a table name deny_keywords in database with this structure:
id
word
1
thief
2
crook
3
killer
and I have an input that user can send a text and this text Placed in variable name $user_text.
Now I want to check if $user_text includes any of deny keywords or no.
Is there a way to do this just using SQL?
A way like this:
SELECT * FROM deny_keywords WHERE %word% like $user_text;

You can create a fulltext index on the word column of the deny_keywords table to accomplish this.
To create the index you would run:
alter table deny_keywords add fulltext(word);
To use the index in the query you are trying to run:
select *
from deny_keywords
where match(word) against ('$user_text' in natural language mode);
A fiddle is here: http://sqlfiddle.com/#!9/443eb6/1/0
For security reasons, you should use mysqli or PDO, where you prepare the statement and bind the user_text variable as a parameter. That's a separate discussion.

This is the solution I found and it works:
SELECT * FROM deny_keywords WHERE INSTR('{$user_text}' , `word`) > 0

FIND_IN_SET with like clause mysql

I have a MySQL table where I am using comma separated values like:
user_name books
abc PHP,Java
xyz Net,Shift,PHP
I can handle comma-separated value searching using the FIND_IN_SET function of MySQL.
Now books names are auto suggested means if any one search with keyword "J" , system should search and match the word Java and give result of user "abc".
I tried to use like clause with FIND_IN_SET but it's not working.
Does anyone have any suggestions?

Not a clean solution but you can use something like this:
SELECT * FROM `library` WHERE `books` LIKE 'J%' OR `books` LIKE '%,J%'

Advanced search in mysql column with row of words separated by coma

Hello everyone as the topic says I am looking for alternative or advanced using of "LIKE".
I have column which contains a row of words p.e. "keyword1,keyword2,another_keyword" and when I use
$sql = mysql_query("SELECT * FROM table WHERE `column` LIKE '%keyword1%' ");
It hardly find it p.e. this example works but when i try to find shorter strings it has problems and sometimes it does not find anything.
I tried put a whitespace after comas and it helped but if there is a way where I can search for match with this specification of column I would be happy.

You may move keywords into individual table.
Or you can use SET field type, if the list of your keywords don't change.

Storing comma separated list of your words is a bad idea example using like in your scenario is hard to find the exact work in comma separated list instead you can add new table which relates to your current table and store each the word in a new row with the associated identity like
table1
id title
1 test1
2 test2
kewords_table
table1_id word
1 word1
1 word2
1 word3
and query will be
select t.*
from table1 t
join kewords_table k
on(t.id = k.table1_id)
where k.word = 'your_keyword'
If you can't alter your structure you can use find_in_set()
SELECT * FROM table WHERE find_in_set('your_keyword',`column`) > 0

try something like this:
SELECT * FROM tablename
WHERE column LIKE '%keyword1%'
OR column LIKE '%keyword2%';
for more info see here:Using SQL LIKE and IN together

MySQL allows you to perform a full-text search based on very complex queries in the Boolean mode along with Boolean operators. This is why the full-text search in Boolean mode is suitable for experienced users.
First You have to add FULLTEXT index to that perticuler column :
ALTER TABLE table_name ADD search_column TEXT CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NULL DEFAULT NULL, ADD FULLTEXT search_column (search_column);
Run following query for searching :
SELECT * FROM table WHERE MATCH(search_column) AGAINST("keyword1")
for more info see here : https://dev.mysql.com/doc/refman/8.0/en/fulltext-boolean.html

How to select rows from a table where a word appears? (MySQL + PHP)

I have to make a search for keywords as part of my Computer Science work.
I have the names and descriptions of several DVD's.
The user has to search a word, and then displayed are all the names of DVD's where the word appeared in either the title or description.
Let's say my columns in my table
were "dvd title" and "description", and the word the person has entered is $keyword.
How would i select rows in mysql where $keyword appears at least once in either columns "dvd title" and "description".
Thanks for reading. Any help appreciated.

You could create a full text index on those columns, but that probably isn't what they want you do do.
You need wildcards, and to you wildcards compare with the keyword LIKE instead of =. A wildcard in mysql is %
SELECT * FROM mutable WHERE dvdtitle like '%keyword%' or description like '%keyword%';
As for using PHP variable and creating the string, you've got to do some of your own homework.

$sql = "SELECT * FROM table_name WHERE dvdtitle LIKE '%".$keyword."%' OR description LIKE '%".$keyword."%'";
Executing the above SQL query would return all the rows in the table that has the specified keyword in either the column dvdtitle or description.

Use this query:
SELECT *
FROM table_name
WHERE dvd_title like '%$keyword%'
OR description like '%$keyword%'

You can use following code sample, it's not a full code but will give you an idea:
$query_str = "select * from dvd_table_name where dvd_title like '%$keyword%' or description like '%$keyword%'";
$qh = mysql_query($query_str);
Then use mysql_fetch_assoc($qh) to retrive data using while loop;

Comma separated values in MySQL "IN" clause

I have a column in one of my table where I store multiple ids seperated by comma's.
Is there a way in which I can use this column's value in the "IN" clause of a query.
The column(city) has values like 6,7,8,16,21,2
I need to use as
select * from table where e_ID in (Select city from locations where e_Id=?)
I am satisfied with Crozin's answer, but I am open to suggestions, views and options.
Feel free to share your views.

Building on the FIND_IN_SET() example from #Jeremy Smith, you can do it with a join so you don't have to run a subquery.
SELECT * FROM table t
JOIN locations l ON FIND_IN_SET(t.e_ID, l.city) > 0
WHERE l.e_ID = ?
This is known to perform very poorly, since it has to do table-scans, evaluating the FIND_IN_SET() function for every combination of rows in table and locations. It cannot make use of an index, and there's no way to improve it.
I know you said you are trying to make the best of a bad database design, but you must understand just how drastically bad this is.
Explanation: Suppose I were to ask you to look up everyone in a telephone book whose first, middle, or last initial is "J." There's no way the sorted order of the book helps in this case, since you have to scan every single page anyway.
The LIKE solution given by #fthiella has a similar problem with regards to performance. It cannot be indexed.
Also see my answer to Is storing a delimited list in a database column really that bad? for other pitfalls of this way of storing denormalized data.
If you can create a supplementary table to store an index, you can map the locations to each entry in the city list:
CREATE TABLE location2city (
location INT,
city INT,
PRIMARY KEY (location, city)
);
Assuming you have a lookup table for all possible cities (not just those mentioned in the table) you can bear the inefficiency one time to produce the mapping:
INSERT INTO location2city (location, city)
SELECT l.e_ID, c.e_ID FROM cities c JOIN locations l
ON FIND_IN_SET(c.e_ID, l.city) > 0;
Now you can run a much more efficient query to find entries in your table:
SELECT * FROM location2city l
JOIN table t ON t.e_ID = l.city
WHERE l.e_ID = ?;
This can make use of an index. Now you just need to take care that any INSERT/UPDATE/DELETE of rows in locations also inserts the corresponding mapping rows in location2city.

From MySQL's point of view you're not storing multiple ids separated by comma - you're storing a text value, which has the exact same meaing as "Hello World" or "I like cakes!" - i.e. it doesn't have any meaing.
What you have to do is to create a separated table that will link two objects from the database together. Read more about many-to-many or one-to-many (depending on your requirements) relationships in SQL-based databases.

Rather than use IN on your query, use FIND_IN_SET (docs):
SELECT * FROM table
WHERE 0 < FIND_IN_SET(e_ID, (
SELECT city FROM locations WHERE e_ID=?))
The usual caveats about first form normalization apply (the database shouldn't store multiple values in a single column), but if you're stuck with it, then the above statement should help.

This does not use IN clause, but it should do what you need:
Select *
from table
where
CONCAT(',', (Select city from locations where e_Id=?), ',')
LIKE
CONCAT('%,', e_ID, ',%')
but you have to make sure that e_ID does not contain any commas or any jolly character.
e.g.
CONCAT(',', '6,7,8,16,21,2', ',') returns ',6,7,8,16,21,2,'
e_ID=1 --> ',6,7,8,16,21,2,' LIKE '%,1,%' ? FALSE
e_ID=6 --> ',6,7,8,16,21,2,' LIKE '%,6,%' ? TRUE
e_ID=21 --> ',6,7,8,16,21,2,' LIKE '%,21,%' ? TRUE
e_ID=2 --> ',6,7,8,16,21,2,' LIKE '%,2,%' ? TRUE
e_ID=3 --> ',6,7,8,16,21,2,' LIKE '%,3,%' ? FALSE
etc.

Don't know if this is what you want to accomplish. With MySQL there is feature to concatenate values from a group GROUP_CONCAT
You can try something like this:
select * from table where e_ID in (Select GROUP_CONCAT(city SEPARATOR ',') from locations where e_Id=?)

this one in for oracle ..here string concatenation is done by wm_concat
select * from table where e_ID in (Select wm_concat(city) from locations where e_Id=?)
yes i agree with raheel shan .. in order put this "in" clause we need to make that column into row below code one do that job.
select * from table where to_char(e_ID)
in (
select substr(city,instr(city,',',1,rownum)+1,instr(city,',',1,rownum+1)-instr(city,',',1,rownum)-1) from
(
select ','||WM_CONCAT(city)||',' city,length(WM_CONCAT(city))-length(replace(WM_CONCAT(city),','))+1 CNT from locations where e_Id=? ) TST
,ALL_OBJECTS OBJ where TST.CNT>=rownum
) ;

you should use
FIND_IN_SET Returns position of value in string of comma-separated values
mysql> SELECT FIND_IN_SET('b','a,b,c,d');
-> 2

You need to "SPLIT" the city column values. It will be like:
SELECT *
FROM table
WHERE e_ID IN (SELECT TO_NUMBER(
SPLIT_STR(city /*string*/
, ',' /*delimiter*/
, 1 /*start_position*/
)
)
FROM locations);
You can read more about the MySQL split_str function here: http://blog.fedecarg.com/2009/02/22/mysql-split-string-function/
Also, I have used the TO_NUMBER function of Oracle here. Please replace it with a proper MySQL function.

IN takes rows so taking comma seperated column for search will not do what you want but if you provide data like this ('1','2','3') this will work but you can not save data like this in your field whatever you insert in the column it will take the whole thing as a string.

You can create a prepared statement dynamically like this
set #sql = concat('select * from city where city_id in (',
(select cities from location where location_id = 3),
')');
prepare in_stmt from #sql;
execute in_stmt;
deallocate prepare in_stmt;

Ref: Use a comma-separated string in an IN () in MySQL
Recently I faced the same problem and this is how I resolved it.
It worked for me, hope this is what you were looking for.
select * from table_name t where (select (CONCAT(',',(Select city from locations l where l.e_Id=?),',')) as city_string) LIKE CONCAT('%,',t.e_ID,',%');
Example: It will look like this
select * from table_name t where ',6,7,8,16,21,2,' LIKE '%,2,%';

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