Output 0 if calculations is negative, else do calculations - mysql

=MAX(IF
(Table_ExternalData_2[name]=$A$2,Table_ExternalData_2[date_booked])) - MIN(IF(Table_ExternalData_2[name]=$A$2,Table_ExternalData_2[date_booked]))
Sorry if this is such an easy question but I can't figure it out. What I'm trying to do is, if the result is negative, the output will be zero, if not then minus the columns.
| Col1 | Col2 |
| 42 | 233 |
If i minus 42 - 233, I will get -191.
How can I tell mysql that if the result is a negative, output 0 and if not then minus the two columns?
SELECT IF(Col1-Col2 =< 0, 0, Col1-Col2)
Is as simple as this?

You can use CASE WHEN (condition) THEN (true) ELSE (false) END
SELECT CASE WHEN (Col1-Col2) =< 0 THEN 0 ELSE (Col1-Col2) END AS Num1 FROM ....

Related

Creating a column being the multiple of others

I need some help. I have 2 colluns from mysql query result: 1 with text, and another with decimal values. Like that:
select desc, value from table a
|5,50 % | 2984.59 |
|Subs | 10951.70 |
|Isent | 3973.17 |
|13,30 % | 560.26 |
From the rows that have the %, I want to multiply the values and create a third result column, rounding up to two decimal places. See above
2984,59 * 0,055 = 164,15245
560,26 * 0,133 = 74,514
I need make the sql query that show something like above.
+-------+-----------+-----------+
|5,50 % | 2984,59 | 164,16 |
|Subs | 10951,70 | 0 or NULL |
|Isent | 3973,17 | 0 or NULL |
|13,30% | 560,26 | 74,52 |
+-------+-----------+-----------+
How i can do it?
Thanks so much for help
It would be better to have floaring numbers in the first place, converting costs time
You have commas in your procentage, but mysql needs dots there
If value isn't always a number, you can use the mysql way to add a 0 0 to it, that remioves all non numerical characters
SELECT `desc`, `value`, (REPLACE(`desc`,',','.') + 0) * `value` / 100 FROM val
desc
value
(REPLACE(`desc`,',','.') + 0) * `value` / 100
5,50 %
2985
164.175
Subs
10952
0
Isent
3973
0
13,30 %
560
74.48
fiddle
SELECT `desc`, `value`, CEIL((REPLACE(`desc`,',','.') + 0) * `value`) / 100 FROM val
desc
value
CEIL((REPLACE(`desc`,',','.') + 0) * `value`) / 100
5,50 %
2985
164.18
Subs
10952
0
Isent
3973
0
13,30 %
560
74.48
fiddle

Two things to do in MySQL IF()

I have a problem concerning the IF() function in MySQL.
I would like to return a string and change the value of a variable. Somwhat like:
IF(#firstRow=1, "Dear" AND #firstRow:=0, "dear")
This outputs only '0' instead of 'Dear'...
I would be very thankful for some input on ways I could solve this problem!
Louis :)
AND is a boolean operator, not a "also do this other thing" operator.
"Dear" AND 0 returns 0 because 0 is treated as false in MySQL and <anything> AND false will return false.
Also because the integer/boolean value of "Dear" is 0 as well. Using a string in a numeric context just reads initial digits in the string, if any, and ignores the rest.
It's not clear what your problem is, but I guess you want to capitalize the word "dear" if the row is the first one in the result set.
Instead of being too clever by half trying to fit the side-effect into your expression, do yourself a favor and break it out into a separate column:
mysql> SELECT IF(#firstRow=1, 'Dear', 'dear'), #firstRow:=0 AS _ignoreThis
-> FROM (SELECT #firstRow:=1) AS _init
-> CROSS JOIN
-> mytable;
+---------------------------------+-------------+
| IF(#firstRow=1, 'Dear', 'dear') | _ignoreThis |
+---------------------------------+-------------+
| Dear | 0 |
| dear | 0 |
| dear | 0 |
+---------------------------------+-------------+
But if you really want to make your code as confusing and unreadable as possible, you can do something like this:
SELECT IF(#firstRow=1, CONCAT('Dear', IF(#firstRow:=0, '', '')), 'dear')
FROM (SELECT #firstRow:=1) AS _init
CROSS JOIN
...
But remember this important metric of code quality: WTFs per minute.
Use a case expression instead of IF() as the syntax is far easier to follow e.g.
select
case when #firstRow = 1 then 'Dear' else 'dear' end AS Salutation
, #firstRow := 0
from (
select 1 n union all
select 2 n union all
select 3
) d
cross join (SELECT #firstRow:=1) var
+---+------------+----------------+
| | Salutation | #firstRow := 0 |
+---+------------+----------------+
| 1 | Dear | 0 |
| 2 | dear | 0 |
| 3 | dear | 0 |
+---+------------+----------------+
Demo

SQL statement equivalent to ternary operator

I would like to create a statement that is equivalent to (x - y == 0) ? return 0 : return 100 in MySQL. Something that might look like this:
SELECT id, [(integer_val - 10 == 0) ? 0 : 100] AS new_val FROM my_table
I want to compare an attribute in each row to a certain number, and if the difference between that number and the number in the row is 0, I want it to give me 0, otherwise, I want it to give me 100.
Example:
Applying this query on my_table (with 10 being the 'compared to' number):
id | integer_val
===================
1 10
2 10
3 3
4 9
Would return this:
id | new_val
===================
1 100
2 100
3 0
4 0
How can I do this?
Try this:
SELECT id, IF(integer_val = 10, 100, 0) AS new_val
FROM my_table;
OR
SELECT id, (CASE WHEN integer_val = 10 THEN 100 ELSE 0 END) AS new_val
FROM my_table;
Use case when statement:
select *, (case when integer_val = 10 then 100 else 0 end) as New_Val
from yourtable
Try using the IF function:
SELECT id, IF(integer_val - 10 = 0, 0, 100) AS new_val FROM my_table
(I stuck with your condition expression, but it can be simplified a bit since integer_value - 10 = 0 has exactly the same truth value as integer_value = 10.)
Note that the IF function is different from MySQL's IF statement used for stored programs.

MySQL Update CASE updates field with "0"

I have a problem by updating my SQL-Table with the CASE statement.
SELECT number,amount,minimuminventory FROM artikel WHERE number=17;
+--------+--------+------------------+
| number | amount | minimuminventory |
+--------+--------+------------------+
| 17 | 10 | 0 |
+--------+--------+------------------+
I have an amount of 10 but when I update my table:
UPDATE artikel
SET amount = CASE WHEN amount - minimuminventory - 2 < 0
THEN amount=amount-2
ELSE amount=99
END
WHERE artnr=17;
Query OK, 1 rows affected (0,01 sec)
Rows matched: 1 Changed: 1 Warnings: 0
mysql updates my table an sets amount to 0
SELECT number,amount,minimuminventory FROM artikel WHERE number=17;
+--------+--------+------------------+
| number | amount | minimuminventory |
+--------+--------+------------------+
| 17 | 0 | 0 |
+--------+--------+------------------+
Do you you see the problem?
amount = CASE WHEN amount - minimuminventory - 2 < 0 THEN amount=amount-2 ELSE amount=99 END
The value from the CASE statement is the intended value for the amount column, but you're doing amount=x again inside the THEN and ELSE parts of it. Change it to this:
amount = CASE WHEN amount - minimuminventory - 2 < 0 THEN amount-2 ELSE 99 END
Do you you see the problem?
In your statement:
UPDATE artikel
SET amount = CASE WHEN amount - minimuminventory - 2 < 0
THEN amount=amount-2
ELSE amount=99
END
WHERE artnr=17;
The comparison is interpreted as boolean but not as assignment.
SET amount = (amount=amount-2) -- comparison as if amount is equal to (17=17-2)
SET amount = (amount=99) -- comparison as if amount is equal to (17=99)
SET amount = false -- i.e. 0, because 17 != 15 or 17 != 99
That resulted a value of 0 in amount column.
Change your update statement as below:
UPDATE artikel
SET amount = CASE WHEN amount - minimuminventory - 2 < 0
THEN amount-2
ELSE 99
END
WHERE artnr=17;

How do I check to see if a value is an integer in MySQL?

I see that within MySQL there are Cast() and Convert() functions to create integers from values, but is there any way to check to see if a value is an integer? Something like is_int() in PHP is what I am looking for.
I'll assume you want to check a string value. One nice way is the REGEXP operator, matching the string to a regular expression. Simply do
select field from table where field REGEXP '^-?[0-9]+$';
this is reasonably fast. If your field is numeric, just test for
ceil(field) = field
instead.
Match it against a regular expression.
c.f. http://forums.mysql.com/read.php?60,1907,38488#msg-38488 as quoted below:
Re: IsNumeric() clause in MySQL??
Posted by: kevinclark ()
Date: August 08, 2005 01:01PM
I agree. Here is a function I created for MySQL 5:
CREATE FUNCTION IsNumeric (sIn varchar(1024)) RETURNS tinyint
RETURN sIn REGEXP '^(-|\\+){0,1}([0-9]+\\.[0-9]*|[0-9]*\\.[0-9]+|[0-9]+)$';
This allows for an optional plus/minus sign at the beginning, one optional decimal point, and the rest numeric digits.
Suppose we have column with alphanumeric field having entries like
a41q
1458
xwe8
1475
asde
9582
.
.
.
.
.
qe84
and you want highest numeric value from this db column (in this case it is 9582) then this query will help you
SELECT Max(column_name) from table_name where column_name REGEXP '^[0-9]+$'
Here is the simple solution for it
assuming the data type is varchar
select * from calender where year > 0
It will return true if the year is numeric else false
This also works:
CAST( coulmn_value AS UNSIGNED ) // will return 0 if not numeric string.
for example
SELECT CAST('a123' AS UNSIGNED) // returns 0
SELECT CAST('123' AS UNSIGNED) // returns 123 i.e. > 0
To check if a value is Int in Mysql, we can use the following query.
This query will give the rows with Int values
SELECT col1 FROM table WHERE concat('',col * 1) = col;
The best i could think of a variable is a int Is a combination with MySQL's functions CAST() and LENGTH().
This method will work on strings, integers, doubles/floats datatypes.
SELECT (LENGTH(CAST(<data> AS UNSIGNED))) = (LENGTH(<data>)) AS is_int
see demo http://sqlfiddle.com/#!9/ff40cd/44
it will fail if the column has a single character value. if column has
a value 'A' then Cast('A' as UNSIGNED) will evaluate to 0 and
LENGTH(0) will be 1. so LENGTH(Cast('A' as UNSIGNED))=LENGTH(0) will
evaluate to 1=1 => 1
True Waqas Malik totally fogotten to test that case. the patch is.
SELECT <data>, (LENGTH(CAST(<data> AS UNSIGNED))) = CASE WHEN CAST(<data> AS UNSIGNED) = 0 THEN CAST(<data> AS UNSIGNED) ELSE (LENGTH(<data>)) END AS is_int;
Results
**Query #1**
SELECT 1, (LENGTH(CAST(1 AS UNSIGNED))) = CASE WHEN CAST(1 AS UNSIGNED) = 0 THEN CAST(1 AS UNSIGNED) ELSE (LENGTH(1)) END AS is_int;
| 1 | is_int |
| --- | ------ |
| 1 | 1 |
---
**Query #2**
SELECT 1.1, (LENGTH(CAST(1 AS UNSIGNED))) = CASE WHEN CAST(1.1 AS UNSIGNED) = 0 THEN CAST(1.1 AS UNSIGNED) ELSE (LENGTH(1.1)) END AS is_int;
| 1.1 | is_int |
| --- | ------ |
| 1.1 | 0 |
---
**Query #3**
SELECT "1", (LENGTH(CAST("1" AS UNSIGNED))) = CASE WHEN CAST("1" AS UNSIGNED) = 0 THEN CAST("1" AS UNSIGNED) ELSE (LENGTH("1")) END AS is_int;
| 1 | is_int |
| --- | ------ |
| 1 | 1 |
---
**Query #4**
SELECT "1.1", (LENGTH(CAST("1.1" AS UNSIGNED))) = CASE WHEN CAST("1.1" AS UNSIGNED) = 0 THEN CAST("1.1" AS UNSIGNED) ELSE (LENGTH("1.1")) END AS is_int;
| 1.1 | is_int |
| --- | ------ |
| 1.1 | 0 |
---
**Query #5**
SELECT "1a", (LENGTH(CAST("1.1" AS UNSIGNED))) = CASE WHEN CAST("1a" AS UNSIGNED) = 0 THEN CAST("1a" AS UNSIGNED) ELSE (LENGTH("1a")) END AS is_int;
| 1a | is_int |
| --- | ------ |
| 1a | 0 |
---
**Query #6**
SELECT "1.1a", (LENGTH(CAST("1.1a" AS UNSIGNED))) = CASE WHEN CAST("1.1a" AS UNSIGNED) = 0 THEN CAST("1.1a" AS UNSIGNED) ELSE (LENGTH("1.1a")) END AS is_int;
| 1.1a | is_int |
| ---- | ------ |
| 1.1a | 0 |
---
**Query #7**
SELECT "a1", (LENGTH(CAST("1.1a" AS UNSIGNED))) = CASE WHEN CAST("a1" AS UNSIGNED) = 0 THEN CAST("a1" AS UNSIGNED) ELSE (LENGTH("a1")) END AS is_int;
| a1 | is_int |
| --- | ------ |
| a1 | 0 |
---
**Query #8**
SELECT "a1.1", (LENGTH(CAST("a1.1" AS UNSIGNED))) = CASE WHEN CAST("a1.1" AS UNSIGNED) = 0 THEN CAST("a1.1" AS UNSIGNED) ELSE (LENGTH("a1.1")) END AS is_int;
| a1.1 | is_int |
| ---- | ------ |
| a1.1 | 0 |
---
**Query #9**
SELECT "a", (LENGTH(CAST("a" AS UNSIGNED))) = CASE WHEN CAST("a" AS UNSIGNED) = 0 THEN CAST("a" AS UNSIGNED) ELSE (LENGTH("a")) END AS is_int;
| a | is_int |
| --- | ------ |
| a | 0 |
see demo
What about:
WHERE table.field = "0" or CAST(table.field as SIGNED) != 0
to test for numeric and the corrolary:
WHERE table.field != "0" and CAST(table.field as SIGNED) = 0
I have tried using the regular expressions listed above, but they do not work for the following:
SELECT '12 INCHES' REGEXP '^(-|\\+){0,1}([0-9]+\\.[0-9]*|[0-9]*\\.[0-9]+|[0-9]+)$' FROM ...
The above will return 1 (TRUE), meaning the test of the string '12 INCHES' against the regular expression above, returns TRUE. It looks like a number based on the regular expression used above. In this case, because the 12 is at the beginning of the string, the regular expression interprets it as a number.
The following will return the right value (i.e. 0) because the string starts with characters instead of digits
SELECT 'TOP 10' REGEXP '^(-|\\+){0,1}([0-9]+\\.[0-9]*|[0-9]*\\.[0-9]+|[0-9]+)$' FROM ...
The above will return 0 (FALSE) because the beginning of the string is text and not numeric.
However, if you are dealing with strings that have a mix of numbers and letters that begin with a number, you will not get the results you want. REGEXP will interpret the string as a valid number when in fact it is not.
This works well for VARCHAR where it begins with a number or not..
WHERE concat('',fieldname * 1) != fieldname
may have restrictions when you get to the larger NNNNE+- numbers
for me the only thing that works is:
CREATE FUNCTION IsNumeric (SIN VARCHAR(1024)) RETURNS TINYINT
RETURN SIN REGEXP '^(-|\\+){0,1}([0-9]+\\.[0-9]*|[0-9]*\\.[0-9]+|[0-9]+)$';
from kevinclark all other return useless stuff for me in case of 234jk456 or 12 inches