I have a table with following Data in a table
abcd
abcd , pgw
ABcd , Pgw
I want output as
Abcd
Abcd , Pgw
Abcd , Pgw
the First letter in capitals and letter after ',' in capital.
to make first letter upper-case use this
select CONCAT(UPPER(LEFT(`field`, 1)), SUBSTRING(`field`, 2)) from mytable
to do it to also to word after comma declare a function like :
DELIMITER ||
CREATE FUNCTION `ucwords`( str VARCHAR(128) ) RETURNS VARCHAR(128) CHARSET latin1
BEGIN
DECLARE c CHAR(1);
DECLARE s VARCHAR(128);
DECLARE i INT DEFAULT 1;
DECLARE BOOL INT DEFAULT 1;
SET s = LCASE( str );
WHILE i < LENGTH( str ) DO
BEGIN
SET c = SUBSTRING( s, i, 1 );
IF c = ',' THEN
SET BOOL = 1;
ELSEIF BOOL=1 THEN
BEGIN
IF c >= 'a' AND c <= 'z' THEN
BEGIN
SET s = CONCAT(LEFT(s,i-1),UCASE(c),SUBSTRING(s,i+1));
SET BOOL = 0;
END;
END IF;
END;
END IF;
SET i = i+1;
END;
END WHILE;
RETURN s;
END ||
DELIMITER ;
and use
select ucwords(`field`) from mytable
Please don't do this if you ever expect your database to scale well. If you're only ever going to be using this for your personal phone book application or equally tiny data sets, you can get away with doing this at select time, as you suggest.
But, if you want a robust scalable database, you should sacrifice space (disk storage) for time (speed). Per-row functions on select statement rarely scale well.
One time-honored and tested way of doing this is to add another column of identical specifications to the one you already have and use an insert/update trigger to populate it with the data in the format you desire.
Then the cost of the transformation is incurred only when you have to (when the data is updated), not every single time you read the data. This amortises the cost across the reads which, in the vast majority of databases, outweigh writes considerably.
This answer shows an SQL formula which seems close to what you want but I do strongly suggest that you use it in a trigger rather than inefficiently running it every select.
take a look at this solution mysql-update-script-problem-all-txt-is-lower-case-just-first-letter-is-upper-cas , it should give you enough information to adapt to what you're trying to do. Change update to SELECT, etc. etc.
Related
Requirements: Before, I used instr() in Oracle to achieve the requirements, but now I want to use MySQL to achieve the same effect, and try to use the functions in MySQL to achieve it.
INSTR(A.SOME_THING.B,".",1,2)<>0 --ORACLE
As far as I can tell, that's not that difficult for simple cases. But, as number of parameters raises, MySQL "replacement" for the same Oracle functionality gets worse.
As your code:
instr(some_thing, '.', 1, 2)
means
search through some_thing
for a dot
starting from the first position
and find dot's second occurrence
you can't do that in a simple manner using MySQL, as you'll need a user-defined function. Something like this (source is INSTR Function - Oracle to MySQL Migration; I suggest you have a look at the whole document. I'm posting code here because links might get broken):
DELIMITER //
CREATE FUNCTION INSTR4 (p_str VARCHAR(8000), p_substr VARCHAR(255),
p_start INT, p_occurrence INT)
RETURNS INT
DETERMINISTIC
BEGIN
DECLARE v_found INT DEFAULT p_occurrence;
DECLARE v_pos INT DEFAULT p_start;
lbl:
WHILE 1=1
DO
-- Find the next occurrence
SET v_pos = LOCATE(p_substr, p_str, v_pos);
-- Nothing found
IF v_pos IS NULL OR v_pos = 0 THEN
RETURN v_pos;
END IF;
-- The required occurrence found
IF v_found = 1 THEN
LEAVE lbl;
END IF;
-- Prepare to find another one occurrence
SET v_found = v_found - 1;
SET v_pos = v_pos + 1;
END WHILE;
RETURN v_pos;
END;
//
DELIMITER ;
Use it as
SELECT INSTR4('abcbcb', 'b', 3, 2);
and get 6 as a result.
In OracleDB the code
INSTR(column, ".", 1, 2) <> 0 --ORACLE
checks does the column contains at least 2 point chars in the value.
In MySQL this can be replaced with, for example,
LENGTH(column) - LENGTH(REPLACE(column, '.', '')) >= 2
Thanks to this answer https://stackoverflow.com/a/8180159/16349298 , i'm able to translate
a string into a temporary table (usable for WHERE <id> IN <tmpTable>.<colomn>)
The only modification i made is at the end (The select) :
CREATE PROCEDURE stringToTmpTable(IN inputString VARCHAR(255), IN sep VARCHAR(255))
BEGIN
declare pos int; -- Keeping track of the next item's position
declare item varchar(100); -- A single item of the input
declare breaker int; -- Safeguard for while loop
-- The string must end with the delimiter
if right(inputString, 1) <> sep then
set inputString = concat(inputString, sep);
end if;
DROP TABLE IF EXISTS MyTemporaryTable;
CREATE TEMPORARY TABLE MyTemporaryTable ( columnName varchar(100) );
set breaker = 0;
while (breaker < 2000) && (length(inputString) > 1) do
-- Iterate looking for the delimiter, add rows to temporary table.
set breaker = breaker + 1;
set pos = INSTR(inputString, sep);
set item = LEFT(inputString, pos - 1);
set inputString = substring(inputString, pos + 1);
insert into MyTemporaryTable values(item);
end while;
SELECT * FROM MyTemporaryTable;
END
I would like to use this process in a function or procedure in order to call it in any procedure that needs it.
So here is the problem :
I don't know how to store the result of this procedure into a variable : i can't use the SELECT * INTO #p FROM ...; like CALL stringToTmpTable(<string>,<separator>) INTO #table;
An other way would be to add OUT parameter to stringToTmpTable() but it can't return multiple rows. Unfortunatly the amount of parameters in the string is variable so i can't define as much variable as there is parameters in the string.
Finally the FIND_IN_SET() isn't the solution i need.
In the worst case I could copy / past the stringToTmpTable() process in any other procedure that needs it, but that doesn't seem like the best way to me.
Any suggestions ?
"i'm able to translate a string into a temporary table" too, but I am using a different method:
SET #input = 'Banana, Apple, Orange, Pears';
WITH RECURSIVE cte1 as (
select
#input as s,
substring_index(substring_index(#input,',',1),',',-1) as w,
length(#input)-length(replace(#input,',','')) x
union all
select
substring_index(s,',',-x),
trim(substring_index(substring_index(substring_index(s,',',-x),',',1),',',-1)) as w,
x-1 x
from cte1 where s<>'' and x>0
)
select * from cte1
DBFIDDLE
But it's a bit of a problem to determine the real problem you have, which is causing you to ask this question. So this is not an answer, but just a different way of selecting all words from a comma-delimted string.
I wrote a function to generate unique id's,its working but sometimes two people are getting same id,I mean duplicates are formed. My unique id looks like
2016-17NLR250001, I deal with only last four digits 0001. I am posting my function please correct it and please help me in avoiding duplicates even though users login into same account or if they do it on same time.
MY FUNCTION:
DELIMITER $$
USE `olmsap`$$
DROP FUNCTION IF EXISTS `fun_generate_uniqueid`$$
CREATE DEFINER=`root`#`%` FUNCTION `fun_generate_uniqueid`( V_DATE DATE,V_MANDALID INT ) RETURNS VARCHAR(30) CHARSET latin1
DETERMINISTIC
BEGIN
DECLARE MDLCODE VARCHAR(5);
SET MDLCODE = ' ';
SELECT COUNT(*) INTO #CNT FROM `st_com_mandal` WHERE MANDAL_VS_MC=V_MANDALID;
SELECT dist_mandal_code INTO MDLCODE FROM `st_com_mandal` WHERE MANDAL_VS_MC=V_MANDALID;
IF #CNT>0 THEN
SET #YR=`FUN_FISCAL_YR`(V_DATE);
SELECT CONCAT(IF(DIST_SAN_CODE='GUN','GNT',DIST_SAN_CODE),IFNULL(`dist_mandal_code`,'NULL'))INTO #MANDAL
FROM `st_com_dist` SCD INNER JOIN `st_com_mandal` STM ON STM.`mandal_dist_id`= SCD.`DIST_VC_DC` WHERE MANDAL_VS_MC=V_MANDALID;
IF MDLCODE >0 THEN
SELECT COUNT(Soil_Sample_ID)+1 INTO #ID FROM `tt_mao_soil_sample_dtls` WHERE MANDAL_ID=V_MANDALID AND SUBSTR(UNIQUE_ID,1,7)=#YR ;
ELSE
SELECT COUNT(Soil_Sample_ID)+1 INTO #ID FROM `tt_mao_soil_sample_dtls` WHERE SUBSTR(UNIQUE_ID,1,14)=CONCAT(#YR,#MANDAL) ;
END IF ;
IF LENGTH(#ID)=1 THEN
SET #ID=CONCAT('000',#ID);
ELSEIF LENGTH(#ID)=2 THEN
SET #ID=CONCAT('00',#ID);
ELSEIF LENGTH(#ID)=3 THEN
SET #ID=CONCAT('0',#ID);
ELSE
SET #ID=#ID;
END IF ;
RETURN CONCAT(#YR,#MANDAL,#ID);
ELSE
RETURN 'Mandal Doesnt Exists';
END IF;
END$$
DELIMITER ;
I do not think community will be able to help you with this question. This is a complex function that requires very careful analysis of table / index access and locking.
The only thing I can recommend is to not use existing table data to calculate next sequence as this is a bad practice.
Besides Race conditions that you are experiencing you will also get problems if the record with the last sequence is deleted.
I suggest you read this to get an idea on how to write a custom sequence generator:
http://en.latindevelopers.com/ivancp/2012/custom-auto-increment-values/
I was wondering if you know of a way I could filter a mysql query to only show the ‘alpha’ characters from a specific field
So something like
SELECT col1, col2, **alpha_chars_only(col3)** FROM table
I am not looking to update only select.
I have been looking at some regex but without much luck most of what turned up was searching for fields that only contain ‘alpha’ chars.
In a much watered down context...
I have col1 which contains abc and col two contains abc123 and I want to match them on alpha chars only. There can be any number of letters or numbers.
Any help very much wel come
You probably need to write a custom function for this. If you want to do it in MySQL, you could create a stored function like this:
DELIMITER $$
drop function if exists alpha_chars_only $$
create function alpha_chars_only (p_string text) returns text
begin
declare v_return_val text default '';
declare v_iter int unsigned default 1;
declare v_length int unsigned default 0;
declare v_char char(1) default null;
set v_length = char_length(p_string);
while (v_iter <= v_length)
do
set v_char = substring(p_string,v_iter,1);
if (v_char REGEXP '[a-z]')
then
set v_return_val = concat(v_return_val,v_char);
end if;
set v_iter = v_iter + 1;
end while;
return v_return_val;
end $$
DELIMITER ;
I have a character string and for reporting/alignment purpose I need to insert a space after each character. Unfortunately I will have to do it in a SQL or I can write format function.
e.g. "abcd123" to be converted it to "a b c d 1 2 3 ".
Since it's for a considerable number of rows I was wondering how optimized it will be to parse each character and build a new string each time?
Any help is appreciated.
Thanks
Here's a quick & dirty mysql function which solves your problem:
delimiter ||
DROP FUNCTION IF EXISTS concat_whitespace||
CREATE FUNCTION concat_whitespace( x longtext) RETURNS longtext
LANGUAGE SQL NOT DETERMINISTIC READS SQL DATA
BEGIN
DECLARE len INT UNSIGNED;
DECLARE erg LONGTEXT;
SET len = LENGTH(x);
REPEAT
SET erg = CONCAT_WS(' ',SUBSTRING(x,len,1),erg);
SET len = len - 1;
UNTIL len < 1 END REPEAT;
return erg;
END;
||
Now try this:
Select concat_whitespace("abcd123")
which returns
"a b c d 1 2 3"
This function basically loops for each character and concats a space. Direction is from end to beginning, which saves a counter variable.
I havn't done any performance test, fur sure you somehow could optimize this..
I would not recommend storing unnecessary spaces in SQL. This will only waste space.
How about writing a custom retrieval method that will return all strings from your DB with spaces after each character?
update tablename set comment= trim(concat(substr(comment, 1,1),space(1),substr(comment, 2,1),space(1),substr(comment, 3,1),space(1),substr(comment, 4,1),space(1),substr(comment, 5,1),space(1),substr(comment, 6,1),substr(comment, 7)));
here comment is column name