I'm trying to create a CONCAT() that gets the last number in the exp_id column, then adds the filename to display as a separate column. The column would display the following.
copy \\\resfs\reo\reoexps\87\5\7040445i.pdf C:\temp\images
CONCAT('copy \\\resfs\reo\reoexps\87\',', SUBSTRING(exp_id, 1,CHAR_LENGTH(exp_id) -1) '\', file_name, 'C:\temp\images') AS D,
try this:
CONCAT('copy ','\\','\\','\\','resfs\\reo\\reoexps\\87\\', SUBSTRING(CAST(exp_id AS char), 1,CHAR_LENGTH(exp_id) -1),'\\', file_name, ' C:\\temp\\images') AS D
The backslash (\) is used as an escape character. Use a double backslash (\\) where you want a literal backslash:
CONCAT('copy \\\\resfs\\reo\\reoexps\\87\\', SUBSTRING(exp_id, 1, CHAR_LENGTH(exp_id) -1), '\\', file_name, 'C:\\temp\\images') AS D
Related
I have a table 'car_purchases' with a 'description' column. The column is a string that includes first name initial followed by full stop, space and last name.
An example of the Description column is
'Car purchased by J. Blow'
I am using 'substring_index' function to extract the letter preceding the '.' in the column string. Like so:
SELECT
Description,
SUBSTRING_INDEX(Description, '.', 1) as TrimInitial,
SUBSTRING_INDEX(
SUBSTRING_INDEX(Description, '.', 1),' ', -1) as trimmed,
length(SUBSTRING_INDEX(
SUBSTRING_INDEX(Description, '.', 1),' ', -1)) as length
from car_purchases;
I will call this query 1.
picture of the result set (Result 1) is as follows
As you can see the problem is that the 'trimmed' column in the select statement starts counting the 2nd delimiter ' ' instead of the first from the right and produces the result 'by J' instead of just 'J'. Further the length column indicates that the string length is 5 instead of 4 so WTF?
However when I perform the following select statement;
select SUBSTRING_INDEX(
SUBSTRING_INDEX('Car purchased by J. Blow', '.', 1),' ', -1); -- query 2
Result = 'J' as 'Result 2'.
As you can see from result 1 the string in column 'Description' is exactly (as far as I can tell) the same as the string from 'Result 2'. But when the substring_index is performed on the column (instead of just the string itself) the result ignores the first delimiter and selects a string from the 2nd delimiter from the right of the string.
I've racked my brains over this and have tried 'by ' and ' by' as delimiters but both options do not produce the desired result of a single character. I do not want to add further complexity to query 1 by using a trim function. I've also tried the cast function on result column 'trimmed' but still no success. I do not want to concat it either.
There is an anomaly in the 'length' column of query 1 where if I change the length function to char_length function like so:
select length(SUBSTRING_INDEX(
SUBSTRING_INDEX(Description, '.', 1),' ', -1)) as length -- result = 5
select char_length(SUBSTRING_INDEX(
SUBSTRING_INDEX(Description, '.', 1),' ', -1)) as length -- result = 4
Can anyone please explain to me why the above select statement would produce 2 different results? I think this is the reason why I am not getting my desired result.
But just to be clear my desired outcome is to get 'J' not 'by J'.
I guess I could try reverse but I dont think this is an acceptable compromise. Also I am not familiar with collation and charset principles except that I just use the defaults.
Cheers Players!!!!
CHAR_LENGTH returns length in characters, so a string with 4 2-byte characters would return 4. LENGTH however returns length in bytes, so a string with 4 2-byte characters would return 8. The discrepancy in your results (including SUBSTRING_INDEX) says that the "space" between by and J is not actually a single-byte space (ASCII 0x20) but a 2-byte character that looks like a space. To workaround this, you could try replacing all unicode characters with spaces using CONVERT and REPLACE. In this example, I have an en-space unicode character in the string between by and J. The CONVERT changes that to a ?, and the REPLACE then converts that to a space:
SELECT SUBSTRING_INDEX( SUBSTRING_INDEX("Car purchased by J. Blow", '.', 1),' ', -1)
Output:
by J
With CONVERT and REPLACE:
SELECT SUBSTRING_INDEX( SUBSTRING_INDEX(REPLACE(CONVERT("Car purchased by J. Blow" USING ASCII), '?', ' '), '.', 1),' ', -1)
Output
J
For your query, you would replace the string with your column name i.e.
SELECT SUBSTRING_INDEX( SUBSTRING_INDEX(REPLACE(CONVERT(description USING ASCII), '?', ' '), '.', 1),' ', -1)
Demo on DBFiddle
I would need to get value from given regexp.
For example:
> :"postalCode";s:4:"3150";
Is there any way I can extract 3150, from this part of column value. Column value stored serialized objects, so postalCode variable can be null type, that way I should check if positive integer follows ;s:POSITIVE_INT:"postalCodeValue
Use SUBSTRING_INDEX:
SELECT
SUBSTRING(SUBSTRING_INDEX(col, '"', -2), 1,
INSTR(SUBSTRING_INDEX(col, '"', -2), '"') - 1) AS num
FROM yourTable;
This query will extract the last quoted number in your string.
Demo
avoiding regexp you could use some string function eg:
SELECT LENGTH(':"postalCode";s:4:"3150"') - LOCATE(':', REVERSE(':"postalCode";s:4:"3150"'))+1
from dual ;
or
SELECT LENGTH(col_name) - LOCATE(':', REVERSE(col_name))+1
from my_table ;
It also work with 2 times SUBSTRING_INDEX
SELECT
SUBSTRING_INDEX (SUBSTRING_INDEX( ':"postalCode";s:4:"3150";', '"',-2) , '"', 1);
I would like to remove the trailing spaces from the expressions in my column and add them to beginning of the expression. So for instance, I currently have the expressions:
Sample_four_space
Sample_two_space
Sample_one_space
I would like to transform this column into:
Sample_four_space
Sample_two_space
Sample_one_space
I have tried this expression:
UPDATE My_Table
SET name = REPLACE(name,'% ',' %')
However, I would like a more robust query that would work for any length of trailing spaces. Can you help me develop a query that will remove all trailing spaces and add them to the beginning of the expression?
If you know all spaces are at the end (as in your example, then you can count them and put them at the beginning:
select concat(space(length(name) - length(replace(name, ' ', ''))),
replace(name, ' ', '')
)
Otherwise the better solution is:
select concat(space( length(name) - length(trim(trailing ' ' from name)) ),
trim(trailing ' ' from name)
)
or:
select concat(space( length(name) - length(rtrim(name)) ),
rtrim(name)
)
Both these cases count the number of spaces (in or at the end of). The space() function then replicates the spaces and concat() puts them at the beginning.
how to format number with "." as thousand separator, and "," as decimal separator in MySql?
I'm using Format function like
SELECT Format(myNumber,2) as myNumberFormatted FROM ...
But return type is a number like:
1,000,000.00
instead i want
1.000.000,00
How to do in MySQL ?
Thanks
MySQL>=5.5:
SELECT FORMAT(10000000.5, 2, 'de_DE') AS format
MySQL<5.5:
SELECT REPLACE(REPLACE(REPLACE(FORMAT(10000000.5,2), ',', ':'), '.', ','), ':', '.') AS format
specify locale.
FORMAT(myNumber, 2, 'de_DE')
SQLFiddle Demo
I have a MySQL database table 'photos' with a column 'filename'.
I need to replace the spaces in the filename column values with underscores.
Is it possible with a single/multiple query? If so how?
You can use the REPLACE function :
REPLACE(str,from_str,to_str)
Returns the string str with all
occurrences of the string from_str
replaced by the string to_str.
REPLACE() performs a case-sensitive
match when searching for from_str.
So, to replace all occurences of a character by another one in all lines of a table, something like this should do :
update photos set filename = replace(filename, ' ', '_');
ie, you search for ' ' in the column filename and use '_' instead ; and put the result back into filename.
update photos set filename = replace(filename,' ', '_');