I am writing a PHP and MySQL application in which i have to concatenate multiple column values into one single column.I would have used the concat() function,but it does not handle null values,and the concat_ws(),which does not return the result in the output i want.
What i need can be achieved in the Oracle database like this:
Select 'The Surname Is'||last_name from employees;
My Issue is how can i achieve this same result with MySQL..without using the above named functions?
CONCAT with IFNULL:
SELECT
CONCAT('The Surname Is ', IFNULL(last_name, 'sadly not available'))
FROM `employees`
#Minesh: CONCAT_WS does not 'take care' of NULL values. To illustrate this...
CONCAT_WS("~",house.name,house.address,house.type)
In the above example, if house.address is NULL the returned result will not contain a neat double tilda (~~) as expected. It will be a tilda separated list with only 1 tilda. eg "fun House~mansion"
You can also use CONCAT_WS function which takes care of NULL values
SELECT
CONCAT_WS(' ','The Surname Is',lastname)
FROM `employees`
Use coalesce to concat an empty string
select concat(coalesce(null, ''));
A little trick: Use empty string like separator with CONCAT_WS (Some times you wan't insert white spaces)
CONCAT_WS('','The Surname Is:',lastname)
FROM `employees`
Related
I have a varchar(255) field within a source table and the following contents:
50339 My great example
2020002 Next ID but different title
202020 Here we go
Now I am processing the data and do an insert select query on it. From this field I would need the INT number at the beginning of the field. IT IS followed by 2 spaces and a text with var length, this text is what I need as well but for another field. In General I want to to put text and ID in two fields which are now in one.
I tried to grab it like this:
SELECT STATUS REGEXP '^(/d{6,8}) ' FROM products_test WHERE STATUS is not null
But then I learned that in MySQL 5.x there are no regexp within the SELECT statement.
How could I seperate those values within a single select statment, so I can use it in my INSERT SELECT?
From the correct solution of user slaakso, resulted another related problem since somtimes the STATUS field is empty which then results in only one insert, but in case there is a value I split it into two fields. So the count does not match.
My case statement with his solution somehow contains a syntax problem:
CASE STATUS WHEN ''
THEN(
NULL,
NULL
)
ELSE(
cast(STATUS as unsigned),
substring(STATUS, locate(' ', STATUS)+3)
)
END
You can do following. Note that you need to treat the columns separately:
select
if(ifnull(status, '')!='', cast(status as unsigned), null),
if(ifnull(status, '')!='', substring(status, locate(' ', status)+2), null)
from products_test;
See db-fiddle
I've searched in mysql query a word in multiple column in java program. The number of column is variable.
It is correct this query:
select * from customer with (city, name) like%'adelaide'%
You can use CONCAT() function:
select * from customer WHERE concat(city,name) like '%adelaide%'
You can add as many columns to the concat function as you like.
Also as you see I changed your like syntax, '%WORD%' and used a simple where clause.
It's better to use CONCAT_WS() function.
CONCAT() returns NULL if any argument is NULL.
CONCAT_WS() skip any NULL values after the separator argument.
multiple like statements can not be used with or directly. You have to use column name for each like statement.
Use multiple like as mentioned below.
Select *
from animals
where
(
[animalscolumn] like ('%dog%') or
[animalscolumn] like ('%cat%') or
[animalscolumn] like ('%gerbil%') or
[animalscolumn] like ('%hamster%') or
[animalscolumn] like ('%guinea pig%')
)
select * from customer with city like%'adelaide'% or name like%'adelaide'%
I'm trying to join two columns of the same table but, if there are null values (in my case they are in the second column), I want to take anyway the row that interests me and, rather than putting the null value, I would put ''. The columns that I want to join are Surname and Name. In other words, I tried to use :
SELECT CONCAT(CSurname, ' ', CName)
FROM Client;
In this way if I have a valid value for surname and a null value for name I obtain null. I use MySql, thanks.
If you want to avoid the problem with a leading space, then the easiest way is probably CONCAT_WS():
SELECT CONCAT_WS(' ', CSurname, CName)
FROM Client;
Unlike most other functions, CONCAT_WS() ignores NULL values (except for the separator), greatly simplifying this logic -- particularly when you are working with more than two columns.
Without it, the equivalent logic could be expressed as:
SELECT CONCAT(COALESCE(CONCAT(CSurname, ' '), ''), COALESCE(CName, ''))
Try the ifnull function
SELECT CONCAT(CSurname, ' ', IFNULL(CName,'')) FROM Client;
I don't have a local mysql installation to try it out but the IFNULL function should achieve what you need.
eg : field name = User_id
Value=abc later i want to insert xyz without disturbing abc Value= abc,xyz i want to insert efg without disturbing abc then Value= abc,xyz,efg and so on
i want to seperating each value by using ","(comma). can any one help me out
In MySQL you could often refer to the value of a column just by using the column name. And to concatenate strings with a separator there's a nifty function called concat_ws (concat with separator).
In your case the code would look something like
UPDATE YourTable
SET Value = CONCAT_WS(',', Value, 'cde')
WHERE User_id = 123;
Good Luck!
MySQL CONCAT_WS() function is used to join two or more strings with separator. The separator specified in the first argument is added between two strings. The separator itself can be a string. If the separator is NULL the result is NULL.
Click hear for more information
I have values stored like this in a field 1,255,230,265.
Is there a function in MySQL that will give me the second value in that string? In this case it'll be 255.
I tried using locate, but that does not seem to be meant for this.
Try this
select SUBSTRING_INDEX(SUBSTRING_INDEX(field_name,',',2),",",-1) from table_name
You might want to use SUBSTRING_INDEX() function.
SELECT SUBSTRING_INDEX(SUBSTRING_INDEX(field,',',2),',',-1)
FROM yourTable.
This grabs everything infront of the second comma, then grabs everything after the last comma (-1)
Try This
select * from Table1 where ',' + Nos+ ',' like '%,255,%'
Refer:
MySQL query finding values in a comma separated string
mysql check if numbers are in a comma separated list
Use FIND_IN_SET() function:
SELECT *
FROM tableA
WHERE FIND_IN_SET(255, columnName)
OR
Use LIKE operator
SELECT *
FROM tableA
WHERE CONCAT(',', columnName, ',') LIKE '%,255,%'