How can I get the number of values specified in a MySQL SET column?
Is there any built function in mysql ?
SELECT id, LENGTH(colname) - LENGTH(REPLACE(colname, ',', '')) + 1 AS set_count
FROM YourTable
This answer:
https://stackoverflow.com/a/10738323/1176436
Assuming you don't have values like '123,123,' (note the comma at the end) this should work:
SELECT
LENGTH(yourColumn) - LENGTH(REPLACE(yourColumn, ',', '')) + 1 AS numberOfItemsInRow
FROM yourTable;
Find more information here.
But it would really be better to normalize your database!
Related
Hi I need help in sorting mysql query.
I have a column, where it contains the data like
R_5_TP(6),
R_5_TP(7),
R_5_TP(8),
R_6_TP(1),
R_6_TP(10),
R_6_TP(6),
R_50_TP(1),
R_7_TP(1),
I need to write a select query using order by and get the result as
R_5_TP(6),
R_5_TP(7),
R_5_TP(8),
R_6_TP(1),
R_6_TP(6),
R_6_TP(10),
R_7_TP(1),
R_50_TP(1),
Please help.Thank you.
This is a bit tricky. I think you want:
order by substring_index(substring_index(col, '_', 2), '_', -1) + 0, -- convert middle value to a number
substring_index(col, '(', -1) + 0 -- convert parenthesized value to number
I have a database that contains a column "Code" where the records have the following format "xx-xxx" and "xx-xx", for the later format i want to add a zero after the "-" to make it "xx-0xx", is there anyway to count the characters after a certain pattern in Mysql
Hmmm. If those are your only two possibilities, you can use case:
select (case when length(code) = 5
then replace(code, '-', '-0')
else code
end) as new_code
If you want to be more general, deconstruct the string and build it back again:
select concat_ws('-', substring_index(code, '-', 1),
lpad(substring_index(code, '-', -1), 3, '0')
)
Yes, you can use the CHAR_LENGTH(str) like this:
SELECT code,CHAR_LENGTH(SUBSTR(code,3))
from table
I have a table which i am using to query and getting its one column which matches regular expression which is (\/.+\/\?).
Content of the resulted column is like:
/Anything here/?
Example output:
\abc\cdf\?....
\ab\?....
\abc\cdf\?....
\sb\?....
where '....' can be anything
Desired result i want is unique values before \? such that rows with duplicate regexp matched content are shown once only like here (\abc\cdf\?.... showing twice instead of onece)
\abc\cdf\?....
\ab\?....
\sb\?....
OR
\abc\cdf\?
\ab\?
\sb\?
I have looked very much but couldn't find anything there is regexp_substr in oracle but that is not working in SQL.
Please if someone could help me with the sql query that would be awesome.
If you want everything before the last \, then you can use substring_index() and some string manipulation:
select substring_index(col, '\\',
length(col) - length(replace(col, '\\', ''))
) as firstpart,
count(*)
from table t
group by substring_index(col, '\\',
length(col) - length(replace(col, '\\', ''))
);
Is there an easy way to replace all the text in a VARCHAR 255 column from "300-21-2" to "300-21-02" with one query?
Thank you.
This is basic SQL
UPDATE tablename
SET columnname = '300-21-02'
WHERE columnname = '300-21-2'
If the pattern is always the same NNN-NN-N then what you need is:
update tablex
set column = concat( substr(column,1,7), lpad(substr(column,8),2,'0') )
see it at fiddle:
http://sqlfiddle.com/#!2/f59fe/1
EDIT As the op showed the pattern
update tablex
set column = CONCAT(
substring_index(col, '-',1), '-',
lpad(substring_index(substring_index(col, '-',-2), '-', 1),2,'0'), '-',
lpad(substring_index(col, '-',-1), 2, '0') )
If you like to convert the first set like 300 to 00300 as your pattern you add the lpad as this: lpad(substring_index(col, '-',1),5,'0')
This should be a lot easier if mysql has support to regex replace, but as it hasnt you have to work with the strings:
from this value: '300-02-1'
from substring_index(col, '-',1) I'm getting: 300
from substring_index(substring_index(col, '-',-2), '-', 1) I'm getting 02 I did this because just put the substring_index(col, '-',2) gave me 300-02 so, i got it from right to left (-2) then i get the first
and substring_index(col, '-',-1) it bring me 1 because it gets the value from right to left
Then I just concatenate it all formatting the ones I want.
i have a mysql table with this sort of data
TACOMA, Washington, 98477
Now i have thousands of such rows. I want the data to be manipulated in such a manner that it appears like:
TACOMA, Washington
Is it possible though mysql or do i have to manually do it.
You can use :
SELECT SUBSTRING_INDEX('TACOMA, Washington, 98477', ',', 2)
You can read more here.
And the update statement :
UPDATE my_table
SET my_col = SUBSTRING_INDEX(my_col, ',', 2)
Where you need to replace my_table with your table name and my_col with the column you need to be updated.
Possibly this way. Count the number of commas (by checking the length against the length with all the commas removed) and then use SUBSTRING_INDEX to get the string up to the number of commas:-
SELECT SUBSTRING_INDEX(col, ',', LENGTH(col) - LENGTH(REPLACE(col, ',', '')))
FROM SomeTable
substring_index(col, ',',-1)
will give the string from last index of comma to end of string
replace(col,concat(',',substring_index(col, ',',-1)),'')