ModelName.all(:having=>"count(receipt_no)>1",:select=>"school_id,group_concat(id SEPARATOR ',') as f_ids,receipt_no,count(distinct id) as id_count,count(receipt_no) as rec_count",:conditions=>"receipt_no is not null",:group=>"receipt_no")
Output is
+------------+-----------+----------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+-----------+
| receipt_no | school_id | id_count | f_ids | rec_count |
+------------+-----------+----------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+-----------+
| 1261 | 1783 | 2 | 557660,557661 | 2 |
| 14/15- | 1783 | 1209 | 68352,77056,113664,56320,68353,77057,113665,56321,68354,56322,68355,81923,173571,113667,56323,68356,94980,56324,68357,56325,68358,80390,56326,68359,80391,110599,56327,80392,885... | 1209 |
| 15- | 1783 | 112 | 344067,344068,344069,344070,344075,326923,373261,373262,345882,360218,344091,361755,347685,341542,347689,360233,351530,358705,352829,324674,341576,324684,360018,368469,371541,3... | 112 |
Here group_concat does not show all the values but the count of items as same as the count receipt no. Suppose the items in the f_ids column is more than 200 character then its not showing all the values . In other case it will show correct value
I got the solution
SET SESSION group_concat_max_len = 1000000;
Run this code in MySQL console, then this code will change default group_concat character limit to 1000000 characters.
If you want to use in rails console,you can use in this following way
sql = "SET SESSION group_concat_max_len = 1000000"
ActiveRecord::Base.connection.execute(sql)
Please note:
This configuration will work only in that session
Related
System info:
$ uname -srvm
Linux 5.15.0-56-generic #62-Ubuntu SMP Tue Nov 22 19:54:14 UTC 2022 x86_64
$ mysql --version
mysql Ver 8.0.31-0ubuntu0.22.04.1 for Linux on x86_64 ((Ubuntu))
I am very inexperienced with MySQL & have been looking for an answer to this for about half a week. I am working with two tables named character_stats & halloffame that I want to join in a query. They look like this:
mysql> SELECT name, level FROM character_stats;
+-----------+-------+
| name | level |
+-----------+-------+
| foo | 0 |
| bar | 0 |
| baz | 3 |
| tester | 4 |
| testertoo | 2 |
+-----------+-------+
mysql> SELECT * from halloffame;
+----+-----------+----------+--------+
| id | charname | fametype | points |
+----+-----------+----------+--------+
| 1 | bar | T | 0 |
| 2 | foo | T | 0 |
| 3 | baz | T | 0 |
| 4 | tester | T | 0 |
| 5 | testertoo | T | 0 |
| 6 | tester | D | 40 |
| 7 | tester | M | 92 |
| 8 | bar | M | 63 |
+----+-----------+----------+--------+
In my query, I want to display all the rows from character_stats & I want to join the points column from halloffame for fametype='M'. If there is no row for fametype='M', I want to set points to 0 for that character name, instead of omitting the entire row as is done in the following:
mysql> SELECT name, level, points FROM character_stats JOIN
-> (SELECT charname, points FROM halloffame WHERE fametype='M')
-> AS hof ON (hof.charname=name);
+--------+-------+--------+
| name | level | points |
+--------+-------+--------+
| tester | 4 | 92 |
| bar | 0 | 63 |
+--------+-------+--------+
So I want it to output this:
+-----------+-------+--------+
| name | level | points |
+-----------+-------+--------+
| foo | 0 | 0 |
| bar | 0 | 63 |
| baz | 3 | 0 |
| tester | 4 | 92 |
| testertoo | 2 | 0 |
+-----------+-------+--------+
I have tried to learn how to use IFNULL, IF-THEN-ELSE, CASE, COALESCE, & COUNT statements from what I have found in documentation & answers on stackoverflow.com. But as I said, I am very inexperienced & don't know how to implement them.
The following works on its own:
SELECT IFNULL((SELECT points FROM halloffame WHERE fametype='M'
AND charname='foo' LIMIT 1), 0) as points;
But I don't know how to join it to the character_stats table. The following would work if I knew how to get the value of character_stats.name before COALESCE is called:
SELECT name, level, 'M' AS fametype, points FROM character_stats
JOIN (SELECT COALESCE((SELECT points FROM halloffame WHERE
fametype='M' AND charname=name LIMIT 1), 0) AS points) AS hof;
According to Adding Default Values on Joining Tables I should be able to use CROSS JOIN, but I am doing something wrong as it still results in Unknown column 'cc.name' in 'where clause':
SELECT name, level, points FROM character_stats
CROSS JOIN (SELECT DISTINCT name FROM character_stats) AS cc
JOIN (SELECT COALESCE((SELECT points FROM halloffame WHERE
fametype='M' AND charname=cc.name LIMIT 1), 0) AS points) AS hof;
Some references I have looked at:
Returning a value even if no result
Usage of MySQL's "IF EXISTS"
Return Default value if no row found
MySQL.. Return '1' if a COUNT returns anything greater than 0
How do write IF ELSE statement in a MySQL query
Simple check for SELECT query empty result
Is there a function equivalent to the Oracle's NVL in MySQL?
MySQL: COALESCE within JOIN
Unknown Column In Where Clause With Join
Adding Default Values on Joining Tables
https://www.tutorialspoint.com/returning-a-value-even-if-there-is-no-result-in-a-mysql-query
I found that I can do the following:
SELECT name, level, COALESCE((SELECT points FROM
halloffame WHERE fametype='M' AND charname=name
LIMIT 1), 0) AS points FROM character_stats;
Though I would still like to know how to do it within a JOIN statement.
Let me say i have a table called test with the following data
+---------+-----------------+
| id | t_number |
+---------+-----------------+
| 1 | 864291100247345 |
| 2 | 355488020906457 |
| 3 | 864296100098739 |
| 4 | 864296100098325 |
| 5 | 864296100119956 |
What i want to do is to be able to write a select statement that returns a 3 rows with two random values and one mandatory value from the t_number column
for example if the mandatory value is 864291100247345 the output should something like below
+---------+-----------------+
| id | t_number |
+---------+-----------------+
| 1 | 864291100247345 |
| 2 | 355488020906457 |
| 4 | 864296100098325 |
OR
+---------+-----------------+
| id | t_number |
+---------+-----------------+
| 1 | 864291100247345 |
| 3 | 864296100098739 |
| 4 | 864296100098325 |
I have tried the below query but it's not yielding the output i expect, in a sense that it does return a result but without the mandatory value
SELECT * FROM test WHERE t_number = 864291100247345 OR id LIMIT 3;
What is the best way to go about this?
Thank you.
You can use order by:
SELECT t.*
FROM test
ORDER BY (t_number = 864291100247345) DESC,
rand()
LIMIT 3;
This returns the mandatory number first and then random numbers after that.
MySQL treats boolean values (the result of the = expression) as numbers in a numeric context, with "1" for true and "0" for false. So the first expression in the order by sorts the result set with the "true" conditions first, followed by the others.
Here is my table:
| ID | NUMBER |
| 1 | 523 |
| 2 | 293 |
| 3 | 948 |
And now, I want to get all NUMBER values but I want to add in result two numbers - 48 - (without upadting existing results). So finally I want print these results:
| NUMBER |
| 48523 |
| 48293 |
| 48948 |
So I need a query, something like this:
SELECT '48' + `number` FROM `table`
but this query doesn't work fine (this query only update column name from NUMBER to 48 + NUMBER).
Any ideas?
Thanks.
You need CONCAT
SELECT CONCAT('48' , `number`) AS number FROM table
Demo
I've got a a table with rows, and one of the rows has a field with data like this
{"name":"Richard","lastname":null,"city":"Olavarria","cityId":null}
And i want to select all the distinct "city" values i've got. Only using mysql server.
Is it possible? I'm trying with something like this
SELECT id FROM table_name WHERE field_name REGEXP '"key_name":"([^"]*)key_word([^"]*)"';
But i can't make the regexp work
Thanks in advance
MySQL has got support for JSON in version 5.7.7
http://mysqlserverteam.com/json-labs-release-native-json-data-type-and-binary-format/
You will be able to use the jsn_extract function to efficiently parse your JSON string.
If you have an older version and you want to solve it purely in mysql then I am afraid you have to treat it as a string and cut the value out of it (just normal string functions or use regular expressions)
This is not elegant but it will work
http://sqlfiddle.com/#!9/97cfd/14
SELECT
DISTINCT(substring(jsonfield, locate('"city":',jsonfield)+8,
locate('","', jsonfield, locate('"city":',jsonfield))-locate('"city":',jsonfield)-8)
)
FROM
ForgeRock
I have wrapped this into a stored function for those constrained to MySQL <5.7.7:
CREATE FUNCTION `json_extract_string`(
p_json text,
p_key text
) RETURNS varchar(40) CHARSET latin1
BEGIN
SET #pattern = CONCAT('"', p_key, '":"');
SET #start_i = LOCATE(#pattern, p_json) + CHAR_LENGTH(#pattern);
if #start_i = CHAR_LENGTH(#pattern) then
SET #end_i = 0;
else
SET #end_i = LOCATE('"', p_json, #start_i) - #start_i;
end if;
RETURN SUBSTR(p_json, #start_i, #end_i);
END
Note this only works with string values but is a bit more robust than #DmitryK's answer, in that it returns an empty string if the key is not found and the key can be anywhere in the JSON string.
Yes , you can definitely to it using JSON_EXTRACT() function in mysql.
lets take a table that contains JSON (table client_services here) :
+-----+-----------+--------------------------------------+
| id | client_id | service_values |
+-----+-----------+------------+-------------------------+
| 100 | 1000 | { "quota": 1,"data_transfer":160000} |
| 101 | 1000 | { "quota": 2,"data_transfer":800000} |
| 102 | 1000 | { "quota": 3,"data_transfer":70000} |
| 103 | 1001 | { "quota": 1,"data_transfer":97000} |
| 104 | 1001 | { "quota": 2,"data_transfer":1760} |
| 105 | 1002 | { "quota": 2,"data_transfer":1060} |
+-----+-----------+--------------------------------------+
To Select each JSON fields , run this query :
SELECT
id, client_id,
json_extract(service_values, '$.quota') AS quota,
json_extract(service_values, '$.data_transfer') AS data_transfer
FROM client_services;
So the output will be :
+-----+-----------+----------------------+
| id | client_id | quota | data_transfer|
+-----+-----------+----------------------+
| 100 | 1000 | 1 | 160000 |
| 101 | 1000 | 2 | 800000 |
| 102 | 1000 | 3 | 70000 |
| 103 | 1001 | 1 | 97000 |
| 104 | 1001 | 2 | 1760 |
| 105 | 1002 | 2 | 1060 |
+-----+-----------+----------------------+
NOW, if you want lets say DISTINCT quota , then run this query :
SELECT
distinct( JSON_EXTRACT(service_values, '$.quota')) AS quota
FROM client_services;
So this will result into your desired output :
+-------+
| quota |
+-------+
| 1 |
| 2 |
| 3 |
+-------+
hope this helps!
See MariaDB's Dynamic Columns.
Also, search this forum for [mysql] [json]; the topic has been discussed often.
This may be a little late, but the accepted answer didn't work for me. I used SUBSTRING_INDEX to achieve the desired result.
SELECT
ID, SUBSTRING_INDEX(SUBSTRING_INDEX(JSON, '"mykey" : "', -1), '",', 1) MYKEY
FROM MY_TABLE;
Hope this helps.
I don't know why i am not getting the exact result
SELECT MAX(MID(order_id,3,20)) As Id FROM `tbl_orders` WHERE `domain_id`=2
+------------+
| id |
+------------+
| 10121452 |
+------------+
Even i tried the same function without MID function
SELECT MAX(order_id) As Id FROM `tbl_orders` WHERE `domain_id`=2
+------------+
| id |
+------------+
| Hy10121452 |
+------------+
any my database have highest order
+--------+------------+
| id | order_id |
+--------+------------+
| 1 | Hy10121452 |
| 2 | Hy10121453 |
| 3 | Hy10121454 |
| 4 | Hy10121455 |
| 5 | Hy10121456 |
| 6 | Hy10121457 |
| 7 | Hy10121458 |
| 8 | Hy10121459 |
| 9 | Hy10121460 |
+--------+------------+
i have to increment in the highest number to generate new order No.
Is i am doing something wrong?
check your database -> table-> column the data does not contain the same values like this abc1 abc2 abc3 xxx1 if you differnt series then the result always wrong
Change MAX(MID(order_id,3,20)) to MAX(MID(order_id,3,))
Syntax:from W3School
SELECT MID(column_name,start[,length]) AS some_name FROM table_name;
where
column_name Required. The field to extract characters from
start Required. Specifies the starting position (starts at 1)
length Optional. The number of characters to return. If omitted, the MID() function returns the rest of the text
Since you want the highest id then you can use order by DESC and limit
SELECT order_id As Id FROM `tbl_orders` WHERE `domain_id`=2 ORDER BY order_id DESC LIMIT 1
Problem Solved i just have to rectify Order_id column it contains the duplicate entries. duplicate entries removed and problem solved like a charm.