Matching records from two tables - mysql

I have two Tables: ads_info and ads.
I want to match records from two tables.
SQL Schema for ads:
| id | title |
|----|-----------------------|
| 1 | This Dog is very nice |
SQL Schema for ads_info:
| id | infotext | tag |
|----|------------------------------|-----------|
| 1 | Dogs can eat a lot of things | dog, pets |
I want to check if the title of the Ads with id 1 has tags in ads_info. I have tried this:
SELECT * FROM `ads` where id = '1' UNION
SELECT * FROM `ads_info` where tag like '%ads.title%'
HERE IS SQL FIDDLE: LINK

Do you want a simple join?
select a.*, ai.tag,
(tag like concat('%', ads.title, '%')) as flag
from ads a join
ads_info ai
on ai.id = a.id;
The flag is, of course, false. It is rather hard to see situations where it would evaluate to true as you have expressed the logic.

Well you can do it this way : DEMO I am sure there are better ways and even this example can be better executed :) But it will maybe help...
First you create function for split and procedure for inserting those values in table(I have used here a answer from here LINK and corrected some small errors):
FUNCTION
CREATE FUNCTION SPLIT_STR(
x VARCHAR(255),
delim VARCHAR(12),
pos INT
)
RETURNS VARCHAR(255)
RETURN REPLACE(SUBSTRING(SUBSTRING_INDEX(x, delim, pos),
LENGTH(SUBSTRING_INDEX(x, delim, pos -1)) + 1),
delim, '');
PROCEDURE
CREATE PROCEDURE ABC(in fullstr VARCHAR(255))
BEGIN
DECLARE a int default 0;
DECLARE str VARCHAR(255);
simple_loop: LOOP
SET a=a+1;
SET str=SPLIT_STR(fullstr,",",a);
IF str='' THEN
LEAVE simple_loop;
END IF;
insert into my_temp_table values (str);
END LOOP simple_loop;
END;
I have created a table for this values:
create table my_temp_table (temp_columns varchar(100));
Called the procedure:
call ABC((select tag from ads_info));
And then you can use this:
Select * from ads B where exists
(select * from my_temp_table where
find_in_set(UPPER(trim(temp_columns)), replace(UPPER(B.TITLE), ' ', ',')) > 0 );
Or this:
SELECT * FROM ads, my_temp_table
WHERE find_in_set(UPPER(trim(temp_columns)), replace(UPPER(ads.TITLE), ' ', ',')) > 0 ;

Related

How to update every each rows in different values in MySQL?

id INT | food TEXT | memo TEXT
1 | Cucumbers | NULL
2 | Dandelions | NULL
3 | Salmons | NULL
3 | Cucumbers | NULL
4 | Tomatoes | NULL
Evening.
I have a table called results that splits each food values in several rows like the above.
A column named id refers to an individual animal, and a column food is an object what the animals would eat.
I would like to fill up a column memo by using REPLACE or UPDATE keywords like this:
3 | Salmons | Mostly liked it, only 15% didn't eat.
3 | Cucumbers | Only 10% have eaten, rest of all didn't even try.
A problem is MySQL always updates the same line like this:
3 | Salmons | Mostly liked it, only 15% didn't eat.
3 | Cucumbers | Mostly liked it, only 15% didn't eat.
This is my progress:
DROP FUNCTION IF EXISTS fx_length;
DROP FUNCTION IF EXISTS fx_splitter;
DROP FUNCTION IF EXISTS fx_split_row;
DROP PROCEDURE IF EXISTS App_forEach_memo;
DELIMITER //
CREATE FUNCTION fx_length(str TEXT, del VARCHAR(2), pos INT)
RETURNS INT
RETURN LENGTH(SUBSTRING_INDEX(str, del, pos - 1)) + 1 //
CREATE FUNCTION fx_splitter(str TEXT, del VARCHAR(2), pos INT)
RETURNS TEXT
RETURN SUBSTRING(SUBSTRING_INDEX(str, del, pos), fx_length(str, del, pos)) //
CREATE FUNCTION fx_split_row(str TEXT, del VARCHAR(2), pos INT)
RETURNS TEXT
BEGIN
DECLARE output TEXT;
SET output = REPLACE(fx_splitter(str, del, pos), del, '');
IF output = '' THEN SET output = NULL; END IF;
RETURN output;
END //
CREATE PROCEDURE App_forEach(IN target INT, strings TEXT)
BEGIN
DECLARE i INT DEFAULT 1;
REPEAT
UPDATE results
SET id = target, memo = fx_split_row(strings, '| ', i)
WHERE id = target;
SET i = i + 1;
UNTIL i = target
END REPEAT;
END //
DELIMITER ;
CALL App_forEach(3, "Mostly liked it, only 15% didn't eat.| Only 10% have eaten, rest of all didn't even try.");
I think I need to change this part SET id = target . . . for counting per same id numbers, but I don't know how to do this.
Are there any ways to update the memo values w/o creating an extra temp table?
Any tips, suggestions and answers for resolving this problem would be huge appreciated.
Thanks.
WITH cte AS ( SELECT food, ROW_NUMBER() OVER () rn
FROM results
WHERE #id = id )
UPDATE results, cte
SET results.memo = TRIM(SUBSTRING_INDEX(SUBSTRING_INDEX(#memo, '|', cte.rn), '|', -1))
WHERE results.food = cte.food
AND results.id = #id
AND cte.rn <= 1 + LENGTH(#memo) - LENGTH(REPLACE(#memo, '|', ''));
fiddle
You may put this query into a procedure if needed.
If you have ancient MySQL version which does not support CTE and window functions then emulate them in subquery using user-defined variables.

Select Next 10 Characters Following Specific String

I'm trying to figure out how to create a single MySQL query that will allow me to display only the next 10 characters following the string "filter" in the Message field. The string "filter" appears at various positions in each record, so I can't use a position filter.
I've been trying to use something like like what I have below, however I've been unable to get the correct query.
SELECT RIGHT(Message,LOCATE('filter',Message) - 10) FROM table
The Message field records within the table looks like:
QgySSW8fwD25iQ.filter0019p3las1-31205-59C3D
6t2fJw.filter0010p3las1-9745-59
filter0025p3las1-13130-59C3D317
And I'm looking for them to look like this after the query:
0019p3las1
0010p3las1
0025p3las1
Any help is greatly appreciated.
Use a combination of LOCATE() within SUBSTRING(). See this SQL Fiddle
CREATE TABLE Table1
(`message` varchar(200))
;
INSERT INTO Table1
(`message`)
VALUES
('QgySSW8fwD25iQ.filter0019p3las1-31205-59C3D'),
('6t2fJw.filter0010p3las1-9745-59'),
('filter0025p3las1-13130-59C3D317')
;
Query 1:
select
SUBSTRING(message,LOCATE('filter',Message)+6,10)
from table1
Note that the +6 is to offset for the length of "filter" because LOCATE finds the position of the "f" and you then need to add 6 for the other characters "ilter". Once that number is determined then just get the next 10 characters.
Results:
| SUBSTRING(message,LOCATE('filter',Message)+6,10) |
|--------------------------------------------------|
| 0019p3las1 |
| 0010p3las1 |
| 0025p3las1 |
See SQLFiddle.
Result table structure
Create table resulttbl (
id int(6) primary key auto_increment ,
resultFIlter varchar(1000)
);
Function to split string
CREATE FUNCTION strSplit(x VARCHAR(65000), delim VARCHAR(12), pos INTEGER)
RETURNS VARCHAR(65000)
BEGIN
DECLARE output VARCHAR(65000);
SET output = REPLACE(SUBSTRING(SUBSTRING_INDEX(x, delim, pos)
, LENGTH(SUBSTRING_INDEX(x, delim, pos - 1)) + 1)
, delim
, '');
IF output = '' THEN SET output = null; END IF;
RETURN output;
END;
Stored procedure to split and insert into result table
CREATE PROCEDURE FilterTable()
BEGIN
DECLARE i INTEGER;
DECLARE endpos INTEGER;
DECLARE fullstr VARCHAR(1000);
DECLARE result VARCHAR(1000);
SET fullstr = 'QgySSW8fwD25iQ.filter0019p3las1-31205-59C3D 6t2fJw.filter0010p3las1-9745-59 filter0025p3las1-13130-59C3D317';
SET i = 2;
SET endpos=LENGTH(fullstr) - LENGTH(REPLACE(fullstr, 'filter', '')) ;
delete from resulttbl;
REPEAT
SET result=strSplit(fullstr, 'filter', i);
IF result IS NOT NULL THEN
SET result=LEFT(result,10);
INSERT INTO resulttbl (resultFIlter) values(result);
END IF;
SET i = i + 1;
UNTIL i >= endpos
END REPEAT;
END ;
Call the procedure using the statement CALL FilterTable().
Now the result of your procedure is available on the table resulttbl.
You can get the values from that table using select statement as SELECT * from resulttbl.
Result
id resultFIlter
1 0019p3las1
2 0010p3las1
3 0025p3las1

MySQL Second (or third) Index Of in String

What would be the simplest way to locate the index of the third space in a string.
My goal is to get CCC out of this space separated list: AAAA BBBB CCCC DDDD EEE. where A and B and D are fixed length, and C is variable length, E F G are optional.
In Java I would use indexof, with a starting point of 10 and that would get me the third space, but it seems that I cannot do that in MySQL, so I thought maybe I could find a 'third index of' function?
You would want to use SUBSTRING_INDEX function like this
SELECT SUBSTRING_INDEX(SUBSTRING_INDEX(field, ' ', 3), ' ', -1)
FROM table
The inner function call would get you to AAAA BBBB CCCC while the outer function call would pare that down to just CCCC.
Generally you can select the nth word in a string using:
SET #N = 3; -- 3rd word
SET #delimiter = ' ';
SELECT
SUBSTRING_INDEX(SUBSTRING_INDEX(words, #delimiter, #N), #delimiter, -1)
FROM
my_table
DROP FUNCTION IF EXISTS `Find_string_by_position`$$
CREATE DEFINER=`root`#`localhost` FUNCTION
`Find_string_by_position`(str VARCHAR(255), delimeter VARCHAR(255),pos INT(2)) RETURNS VARCHAR(255) CHARSET utf8mb4 BEGIN
DECLARE s VARCHAR(255);
DECLARE d VARCHAR(255);
DECLARE p INT DEFAULT 1;
DECLARE val VARCHAR(255);
SET s = LCASE(str);
SET d = delimeter;
SET p = pos;
SELECT SUBSTRING_INDEX(SUBSTRING_INDEX(s,d,p),d,-1) INTO #val;
RETURN #val;
END$$
DELIMITER ;
use below query to find any random id from table after group by.
Here id is the autoincrement_id.
SELECT SUBSTRING_INDEX(SUBSTRING_INDEX(GROUP_CONCAT(id),",",FLOOR(RAND()*COUNT(DISTINCT id))+1),",",-1) AS random_id FROM tableName GROUP BY groupbyColumn
Id
Name
Department
1
Amit Kumar Sharma
Computer Science
*You can extract third string by simple query
Query :-
SELECT SUBSTRING_INDEX(Name, ' ', -1) as last_name FROM table_name
Output :-
Sharma

How can I simulate an array variable in MySQL?

It appears that MySQL doesn't have array variables. What should I use instead?
There seem to be two alternatives suggested: A set-type scalar and temporary tables. The question I linked to suggests the former. But is it good practice to use these instead of array variables? Alternatively, if I go with sets, what would be the set-based idiom equivalent to foreach?
Well, I've been using temporary tables instead of array variables. Not the greatest solution, but it works.
Note that you don't need to formally define their fields, just create them using a SELECT:
DROP TEMPORARY TABLE IF EXISTS my_temp_table;
CREATE TEMPORARY TABLE my_temp_table
SELECT first_name FROM people WHERE last_name = 'Smith';
(See also Create temporary table from select statement without using Create Table.)
You can achieve this in MySQL using WHILE loop:
SET #myArrayOfValue = '2,5,2,23,6,';
WHILE (LOCATE(',', #myArrayOfValue) > 0)
DO
SET #value = ELT(1, #myArrayOfValue);
SET #myArrayOfValue= SUBSTRING(#myArrayOfValue, LOCATE(',',#myArrayOfValue) + 1);
INSERT INTO `EXEMPLE` VALUES(#value, 'hello');
END WHILE;
EDIT:
Alternatively you can do it using UNION ALL:
INSERT INTO `EXEMPLE`
(
`value`, `message`
)
(
SELECT 2 AS `value`, 'hello' AS `message`
UNION ALL
SELECT 5 AS `value`, 'hello' AS `message`
UNION ALL
SELECT 2 AS `value`, 'hello' AS `message`
UNION ALL
...
);
Try using FIND_IN_SET() function of MySql
e.g.
SET #c = 'xxx,yyy,zzz';
SELECT * from countries
WHERE FIND_IN_SET(countryname,#c);
Note: You don't have to SET variable in StoredProcedure if you are passing parameter with CSV values.
Nowadays using a JSON array would be an obvious answer.
Since this is an old but still relevant question I produced a short example.
JSON functions are available since mySQL 5.7.x / MariaDB 10.2.3
I prefer this solution over ELT() because it's really more like an array and this 'array' can be reused in the code.
But be careful: It (JSON) is certainly much slower than using a temporary table. Its just more handy. imo.
Here is how to use a JSON array:
SET #myjson = '["gmail.com","mail.ru","arcor.de","gmx.de","t-online.de",
"web.de","googlemail.com","freenet.de","yahoo.de","gmx.net",
"me.com","bluewin.ch","hotmail.com","hotmail.de","live.de",
"icloud.com","hotmail.co.uk","yahoo.co.jp","yandex.ru"]';
SELECT JSON_LENGTH(#myjson);
-- result: 19
SELECT JSON_VALUE(#myjson, '$[0]');
-- result: gmail.com
And here a little example to show how it works in a function/procedure:
DELIMITER //
CREATE OR REPLACE FUNCTION example() RETURNS varchar(1000) DETERMINISTIC
BEGIN
DECLARE _result varchar(1000) DEFAULT '';
DECLARE _counter INT DEFAULT 0;
DECLARE _value varchar(50);
SET #myjson = '["gmail.com","mail.ru","arcor.de","gmx.de","t-online.de",
"web.de","googlemail.com","freenet.de","yahoo.de","gmx.net",
"me.com","bluewin.ch","hotmail.com","hotmail.de","live.de",
"icloud.com","hotmail.co.uk","yahoo.co.jp","yandex.ru"]';
WHILE _counter < JSON_LENGTH(#myjson) DO
-- do whatever, e.g. add-up strings...
SET _result = CONCAT(_result, _counter, '-', JSON_VALUE(#myjson, CONCAT('$[',_counter,']')), '#');
SET _counter = _counter + 1;
END WHILE;
RETURN _result;
END //
DELIMITER ;
SELECT example();
Dont know about the arrays, but there is a way to store comma-separated lists in normal VARCHAR column.
And when you need to find something in that list you can use the FIND_IN_SET() function.
I know that this is a bit of a late response, but I recently had to solve a similar problem and thought that this may be useful to others.
Background
Consider the table below called 'mytable':
The problem was to keep only latest 3 records and delete any older records whose systemid=1 (there could be many other records in the table with other systemid values)
It would be good if you could do this simply using the statement
DELETE FROM mytable WHERE id IN (SELECT id FROM `mytable` WHERE systemid=1 ORDER BY id DESC LIMIT 3)
However this is not yet supported in MySQL and if you try this then you will get an error like
...doesn't yet support 'LIMIT & IN/ALL/SOME subquery'
So a workaround is needed whereby an array of values is passed to the IN selector using variable. However, as variables need to be single values, I would need to simulate an array. The trick is to create the array as a comma separated list of values (string) and assign this to the variable as follows
SET #myvar = (SELECT GROUP_CONCAT(id SEPARATOR ',') AS myval FROM (SELECT * FROM `mytable` WHERE systemid=1 ORDER BY id DESC LIMIT 3 ) A GROUP BY A.systemid);
The result stored in #myvar is
5,6,7
Next, the FIND_IN_SET selector is used to select from the simulated array
SELECT * FROM mytable WHERE FIND_IN_SET(id,#myvar);
The combined final result is as follows:
SET #myvar = (SELECT GROUP_CONCAT(id SEPARATOR ',') AS myval FROM (SELECT * FROM `mytable` WHERE systemid=1 ORDER BY id DESC LIMIT 3 ) A GROUP BY A.systemid);
DELETE FROM mytable WHERE FIND_IN_SET(id,#myvar);
I am aware that this is a very specific case. However it can be modified to suit just about any other case where a variable needs to store an array of values.
I hope that this helps.
DELIMITER $$
CREATE DEFINER=`mysqldb`#`%` PROCEDURE `abc`()
BEGIN
BEGIN
set #value :='11,2,3,1,';
WHILE (LOCATE(',', #value) > 0) DO
SET #V_DESIGNATION = SUBSTRING(#value,1, LOCATE(',',#value)-1);
SET #value = SUBSTRING(#value, LOCATE(',',#value) + 1);
select #V_DESIGNATION;
END WHILE;
END;
END$$
DELIMITER ;
Maybe create a temporary memory table with columns (key, value) if you want associative arrays. Having a memory table is the closest thing to having arrays in mysql
Here’s how I did it.
First, I created a function that checks whether a Long/Integer/whatever value is in a list of values separated by commas:
CREATE DEFINER = 'root'#'localhost' FUNCTION `is_id_in_ids`(
`strIDs` VARCHAR(255),
`_id` BIGINT
)
RETURNS BIT(1)
NOT DETERMINISTIC
CONTAINS SQL
SQL SECURITY DEFINER
COMMENT ''
BEGIN
DECLARE strLen INT DEFAULT 0;
DECLARE subStrLen INT DEFAULT 0;
DECLARE subs VARCHAR(255);
IF strIDs IS NULL THEN
SET strIDs = '';
END IF;
do_this:
LOOP
SET strLen = LENGTH(strIDs);
SET subs = SUBSTRING_INDEX(strIDs, ',', 1);
if ( CAST(subs AS UNSIGNED) = _id ) THEN
-- founded
return(1);
END IF;
SET subStrLen = LENGTH(SUBSTRING_INDEX(strIDs, ',', 1));
SET strIDs = MID(strIDs, subStrLen+2, strLen);
IF strIDs = NULL or trim(strIds) = '' THEN
LEAVE do_this;
END IF;
END LOOP do_this;
-- not founded
return(0);
END;
So now you can search for an ID in a comma-separated list of IDs, like this:
select `is_id_in_ids`('1001,1002,1003',1002);
And you can use this function inside a WHERE clause, like this:
SELECT * FROM table1 WHERE `is_id_in_ids`('1001,1002,1003',table1_id);
This was the only way I found to pass an "array" parameter to a PROCEDURE.
I'm surprised none of the answers mention ELT/FIELD.
ELT/FIELD works very similar to an array especially if you have static data.
FIND_IN_SET also works similar but doesn't have a built in complementary
function but it's easy enough to write one.
mysql> select elt(2,'AA','BB','CC');
+-----------------------+
| elt(2,'AA','BB','CC') |
+-----------------------+
| BB |
+-----------------------+
1 row in set (0.00 sec)
mysql> select field('BB','AA','BB','CC');
+----------------------------+
| field('BB','AA','BB','CC') |
+----------------------------+
| 2 |
+----------------------------+
1 row in set (0.00 sec)
mysql> select find_in_set('BB','AA,BB,CC');
+------------------------------+
| find_in_set('BB','AA,BB,CC') |
+------------------------------+
| 2 |
+------------------------------+
1 row in set (0.00 sec)
mysql> SELECT SUBSTRING_INDEX(SUBSTRING_INDEX('AA,BB,CC',',',2),',',-1);
+-----------------------------------------------------------+
| SUBSTRING_INDEX(SUBSTRING_INDEX('AA,BB,CC',',',2),',',-1) |
+-----------------------------------------------------------+
| BB |
+-----------------------------------------------------------+
1 row in set (0.01 sec)
Is an array variable really necessary?
I ask because I originally landed here wanting to add an array as a MySQL table variable. I was relatively new to database design and trying to think of how I'd do it in a typical programming language fashion.
But databases are different. I thought I wanted an array as a variable, but it turns out that's just not a common MySQL database practice.
Standard Practice
The alternative solution to arrays is to add an additional table, and then reference your original table with a foreign key.
As an example, let's imagine an application that keeps track of all the items every person in a household wants to buy at the store.
The commands for creating the table I originally envisioned would have looked something like this:
#doesn't work
CREATE TABLE Person(
name VARCHAR(50) PRIMARY KEY
buy_list ARRAY
);
I think I envisioned buy_list to be a comma-separated string of items or something like that.
But MySQL doesn't have an array type field, so I really needed something like this:
CREATE TABLE Person(
name VARCHAR(50) PRIMARY KEY
);
CREATE TABLE BuyList(
person VARCHAR(50),
item VARCHAR(50),
PRIMARY KEY (person, item),
CONSTRAINT fk_person FOREIGN KEY (person) REFERENCES Person(name)
);
Here we define a constraint named fk_person. It says that the 'person' field in BuyList is a foreign key. In other words, it's a primary key in another table, specifically the 'name' field in the Person table, which is what REFERENCES denotes.
We also defined the combination of person and item to be the primary key, but technically that's not necessary.
Finally, if you want to get all the items on a person's list, you can run this query:
SELECT item FROM BuyList WHERE person='John';
This gives you all the items on John's list. No arrays necessary!
This is my solution to use a variable containing a list of elements.
You can use it in simple queries (no need to use store procedures or create tables).
I found somewhere else on the site the trick to use the JSON_TABLE function (it works in mysql 8, I dunno of it works in other versions).
set #x = '1,2,3,4' ;
select c.NAME
from colors c
where
c.COD in (
select *
from json_table(
concat('[',#x,']'),
'$[*]' columns (id int path '$') ) t ) ;
Also, you may need to manage the case of one or more variables set to empty_string.
In this case I added another trick (the query does not return error even if x, y, or both x and y are empty strings):
set #x = '' ;
set #y = 'yellow' ;
select c.NAME
from colors
where
if(#y = '', 1 = 1, c.NAME = #y)
and if(#x = '', 1, c.COD) in (
select *
from json_table(
concat('[',if(#x = '', 1, #x),']'),
'$[*]' columns (id int path '$') ) t) ;
This works fine for list of values:
SET #myArrayOfValue = '2,5,2,23,6,';
WHILE (LOCATE(',', #myArrayOfValue) > 0)
DO
SET #value = ELT(1, #myArrayOfValue);
SET #STR = SUBSTRING(#myArrayOfValue, 1, LOCATE(',',#myArrayOfValue)-1);
SET #myArrayOfValue = SUBSTRING(#myArrayOfValue, LOCATE(',', #myArrayOfValue) + 1);
INSERT INTO `Demo` VALUES(#STR, 'hello');
END WHILE;
Both versions using sets didn't work for me (tested with MySQL 5.5). The function ELT() returns the whole set. Considering the WHILE statement is only avaible in PROCEDURE context i added it to my solution:
DROP PROCEDURE IF EXISTS __main__;
DELIMITER $
CREATE PROCEDURE __main__()
BEGIN
SET #myArrayOfValue = '2,5,2,23,6,';
WHILE (LOCATE(',', #myArrayOfValue) > 0)
DO
SET #value = LEFT(#myArrayOfValue, LOCATE(',',#myArrayOfValue) - 1);
SET #myArrayOfValue = SUBSTRING(#myArrayOfValue, LOCATE(',',#myArrayOfValue) + 1);
END WHILE;
END;
$
DELIMITER ;
CALL __main__;
To be honest, i don't think this is a good practice. Even if its realy necessary, this is barely readable and quite slow.
Isn't the point of arrays to be efficient? If you're just iterating through values, I think a cursor on a temporary (or permanent) table makes more sense than seeking commas, no? Also cleaner. Lookup "mysql DECLARE CURSOR".
For random access a temporary table with numerically indexed primary key. Unfortunately the fastest access you'll get is a hash table, not true random access.
Another way to see the same problem.
Hope helpfull
DELIMITER $$
CREATE PROCEDURE ARR(v_value VARCHAR(100))
BEGIN
DECLARE v_tam VARCHAR(100);
DECLARE v_pos VARCHAR(100);
CREATE TEMPORARY TABLE IF NOT EXISTS split (split VARCHAR(50));
SET v_tam = (SELECT (LENGTH(v_value) - LENGTH(REPLACE(v_value,',',''))));
SET v_pos = 1;
WHILE (v_tam >= v_pos)
DO
INSERT INTO split
SELECT SUBSTRING_INDEX(SUBSTRING_INDEX(v_value,',',v_pos),',', -1);
SET v_pos = v_pos + 1;
END WHILE;
SELECT * FROM split;
DROP TEMPORARY TABLE split;
END$$
CALL ARR('1006212,1006404,1003404,1006505,444,');
If we have one table like that
mysql> select * from user_mail;
+------------+-------+
| email | user |
+------------+-------+-
| email1#gmail | 1 |
| email2#gmail | 2 |
+------------+-------+--------+------------+
and the array table:
mysql> select * from user_mail_array;
+------------+-------+-------------+
| email | user | preferences |
+------------+-------+-------------+
| email1#gmail | 1 | 1 |
| email1#gmail | 1 | 2 |
| email1#gmail | 1 | 3 |
| email1#gmail | 1 | 4 |
| email2#gmail | 2 | 5 |
| email2#gmail | 2 | 6 |
We can select the rows of the second table as one array with CONCAT function:
mysql> SELECT t1.*, GROUP_CONCAT(t2.preferences) AS preferences
FROM user_mail t1,user_mail_array t2
where t1.email=t2.email and t1.user=t2.user
GROUP BY t1.email,t1.user;
+------------+-------+--------+------------+-------------+
| email | user | preferences |
+------------+-------+--------+------------+-------------+
|email1#gmail | 1 | 1,3,2,4 |
|email2#gmail | 2 | 5,6 |
+------------+-------+--------+------------+-------------+
In MYSQL version after 5.7.x, you can use JSON type to store an array. You can get value of an array by a key via MYSQL.
Inspired by the function ELT(index number, string1, string2, string3,…),I think the following example works as an array example:
set #i := 1;
while #i <= 3
do
insert into table(val) values (ELT(#i ,'val1','val2','val3'...));
set #i = #i + 1;
end while;
Hope it help.
Here is an example for MySQL for looping through a comma delimited string.
DECLARE v_delimited_string_access_index INT;
DECLARE v_delimited_string_access_value VARCHAR(255);
DECLARE v_can_still_find_values_in_delimited_string BOOLEAN;
SET v_can_still_find_values_in_delimited_string = true;
SET v_delimited_string_access_index = 0;
WHILE (v_can_still_find_values_in_delimited_string) DO
SET v_delimited_string_access_value = get_from_delimiter_split_string(in_array, ',', v_delimited_string_access_index); -- get value from string
SET v_delimited_string_access_index = v_delimited_string_access_index + 1;
IF (v_delimited_string_access_value = '') THEN
SET v_can_still_find_values_in_delimited_string = false; -- no value at this index, stop looping
ELSE
-- DO WHAT YOU WANT WITH v_delimited_string_access_value HERE
END IF;
END WHILE;
this uses the get_from_delimiter_split_string function defined here: https://stackoverflow.com/a/59666211/3068233
I Think I can improve on this answer. Try this:
The parameter 'Pranks' is a CSV. ie. '1,2,3,4.....etc'
CREATE PROCEDURE AddRanks(
IN Pranks TEXT
)
BEGIN
DECLARE VCounter INTEGER;
DECLARE VStringToAdd VARCHAR(50);
SET VCounter = 0;
START TRANSACTION;
REPEAT
SET VStringToAdd = (SELECT TRIM(SUBSTRING_INDEX(Pranks, ',', 1)));
SET Pranks = (SELECT RIGHT(Pranks, TRIM(LENGTH(Pranks) - LENGTH(SUBSTRING_INDEX(Pranks, ',', 1))-1)));
INSERT INTO tbl_rank_names(rank)
VALUES(VStringToAdd);
SET VCounter = VCounter + 1;
UNTIL (Pranks = '')
END REPEAT;
SELECT VCounter AS 'Records added';
COMMIT;
END;
This method makes the searched string of CSV values progressively shorter with each iteration of the loop, which I believe would be better for optimization.
I would try something like this for multiple collections. I'm a MySQL beginner. Sorry about the function names, couldn't decide on what names would be best.
delimiter //
drop procedure init_
//
create procedure init_()
begin
CREATE TEMPORARY TABLE if not exists
val_store(
realm varchar(30)
, id varchar(30)
, val varchar(255)
, primary key ( realm , id )
);
end;
//
drop function if exists get_
//
create function get_( p_realm varchar(30) , p_id varchar(30) )
returns varchar(255)
reads sql data
begin
declare ret_val varchar(255);
declare continue handler for 1146 set ret_val = null;
select val into ret_val from val_store where id = p_id;
return ret_val;
end;
//
drop procedure if exists set_
//
create procedure set_( p_realm varchar(30) , p_id varchar(30) , p_val varchar(255) )
begin
call init_();
insert into val_store (realm,id,val) values (p_realm , p_id , p_val) on duplicate key update val = p_val;
end;
//
drop procedure if exists remove_
//
create procedure remove_( p_realm varchar(30) , p_id varchar(30) )
begin
call init_();
delete from val_store where realm = p_realm and id = p_id;
end;
//
drop procedure if exists erase_
//
create procedure erase_( p_realm varchar(30) )
begin
call init_();
delete from val_store where realm = p_realm;
end;
//
call set_('my_array_table_name','my_key','my_value');
select get_('my_array_table_name','my_key');
Rather than Saving data as a array or in one row only you should be making diffrent rows for every value received. This will make it much simpler to understand rather than putting all together.
Have you tried using PHP's serialize()?
That allows you to store the contents of a variable's array in a string PHP understands and is safe for the database (assuming you've escaped it first).
$array = array(
1 => 'some data',
2 => 'some more'
);
//Assuming you're already connected to the database
$sql = sprintf("INSERT INTO `yourTable` (`rowID`, `rowContent`) VALUES (NULL, '%s')"
, serialize(mysql_real_escape_string($array, $dbConnection)));
mysql_query($sql, $dbConnection) or die(mysql_error());
You can also do the exact same without a numbered array
$array2 = array(
'something' => 'something else'
);
or
$array3 = array(
'somethingNew'
);

MySql: Count amount of times the words occur in a column

For instance, if I have data in a column like this
data
I love book
I love apple
I love book
I hate apple
I hate apple
How can I get result like this
I = 5
love = 3
hate = 2
book = 2
apple = 3
Can we achieve this with MySQL?
Here is a solution only using a query:
SELECT SUM(total_count) as total, value
FROM (
SELECT count(*) AS total_count, REPLACE(REPLACE(REPLACE(x.value,'?',''),'.',''),'!','') as value
FROM (
SELECT SUBSTRING_INDEX(SUBSTRING_INDEX(t.sentence, ' ', n.n), ' ', -1) value
FROM table_name t CROSS JOIN
(
SELECT a.N + b.N * 10 + 1 n
FROM
(SELECT 0 AS N UNION ALL SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3 UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL SELECT 6 UNION ALL SELECT 7 UNION ALL SELECT 8 UNION ALL SELECT 9) a
,(SELECT 0 AS N UNION ALL SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3 UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL SELECT 6 UNION ALL SELECT 7 UNION ALL SELECT 8 UNION ALL SELECT 9) b
ORDER BY n
) n
WHERE n.n <= 1 + (LENGTH(t.sentence) - LENGTH(REPLACE(t.sentence, ' ', '')))
ORDER BY value
) AS x
GROUP BY x.value
) AS y
GROUP BY value
Here is the full working fiddle: http://sqlfiddle.com/#!2/17481a/1
First we do a query to extract all words as explained here by #peterm(follow his instructions if you want to customize the total number of words processed). Then we convert that into a sub-query and then we COUNT and GROUP BY the value of each word, and then make another query on top of that to GROUP BY not grouped words cases where accompanied signs might be present. ie: hello = hello! with a REPLACE
If you want to perform such kind of text analysis, I would recommend using something like lucene, to get the termcount for each term in the document.
This query is going to take a long time to run if your table is of any decent size. It may be better to keep track of the counts in a separate table and update that table as values are inserted or, if real time results are not necessary, to only run this query every so often to update the counts table and pull your data from it. That way, you're not spending minutes to get data from this complex query.
Here's what I've for you so far. It's a good start. The only thing you need to do is modify it to iterate through the words in each row. You could use a cursor or a subquery.
Create test table:
create table tbl(str varchar(100) );
insert into tbl values('data');
insert into tbl values('I love book');
insert into tbl values('I love apple');
insert into tbl values('I love book');
insert into tbl values('I hate apple');
insert into tbl values('I hate apple');
Pull data from test table:
SELECT DISTINCT str AS Word, COUNT(str) AS Frequency FROM tbl GROUP BY str;
create a user defined function like this and use it in your query
DELIMITER $$
CREATE FUNCTION `getCount`(myStr VARCHAR(1000), myword VARCHAR(100))
RETURNS INT
BEGIN
DECLARE cnt INT DEFAULT 0;
DECLARE result INT DEFAULT 1;
WHILE (result > 0) DO
SET result = INSTR(myStr, myword);
IF(result > 0) THEN
SET cnt = cnt + 1;
SET myStr = SUBSTRING(myStr, result + LENGTH(myword));
END IF;
END WHILE;
RETURN cnt;
END$$
DELIMITER ;
Hope it helps
Refer This
Split-string procedure is not my job. You can find it here
http://forge.mysql.com/tools/tool.php?id=4
I wrote you the rest of code.
drop table if exists mytable;
create table mytable (
id int not null auto_increment primary key,
mytext varchar(1000)
) engine = myisam;
insert into mytable (mytext)
values ('I love book,but book sucks!What do you,think about it? me too'),('I love apple! it rulez.,No, it sucks a lot!!!'),('I love book'),('I hate apple!!! Me too.,!'),('I hate apple');
drop table if exists mywords;
create table mywords (
id int not null auto_increment primary key,
word varchar(50)
) engine = myisam;
delimiter //
drop procedure if exists split_string //
create procedure split_string (
in input text
, in `delimiter` varchar(10)
)
sql security invoker
begin
declare cur_position int default 1 ;
declare remainder text;
declare cur_string varchar(1000);
declare delimiter_length tinyint unsigned;
drop temporary table if exists SplitValues;
create temporary table SplitValues (
value varchar(1000) not null
) engine=myisam;
set remainder = input;
set delimiter_length = char_length(delimiter);
while char_length(remainder) > 0 and cur_position > 0 do
set cur_position = instr(remainder, `delimiter`);
if cur_position = 0 then
set cur_string = remainder;
else
set cur_string = left(remainder, cur_position - 1);
end if;
if trim(cur_string) != '' then
insert into SplitValues values (cur_string);
end if;
set remainder = substring(remainder, cur_position + delimiter_length);
end while;
end //
delimiter ;
delimiter //
drop procedure if exists single_words//
create procedure single_words()
begin
declare finish int default 0;
declare str varchar(200);
declare cur_table cursor for select replace(replace(replace(replace(mytext,'!',' '),',',' '),'.',' '),'?',' ') from mytable;
declare continue handler for not found set finish = 1;
truncate table mywords;
open cur_table;
my_loop:loop
fetch cur_table into str;
if finish = 1 then
leave my_loop;
end if;
call split_string(str,' ');
insert into mywords (word) select * from splitvalues;
end loop;
close cur_table;
end;//
delimiter ;
call single_words();
select word,count(*) as word_count
from mywords
group by word;
+-------+------------+
| word | word_count |
+-------+------------+
| a | 1 |
| about | 1 |
| apple | 3 |
| book | 3 |
| but | 1 |
| do | 1 |
| hate | 2 |
| I | 5 |
| it | 3 |
| lot | 1 |
| love | 3 |
| me | 2 |
| No | 1 |
| rulez | 1 |
| sucks | 2 |
| think | 1 |
| too | 2 |
| What | 1 |
| you | 1 |
+-------+------------+
19 rows in set (0.00 sec)
The code must be improved in order to consider any punctuation but this is the general idea.