SQL statement equivalent to ternary operator - mysql

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.

Related

Add a digit to the end of an SQL result

I want the result to add number in the end in specific cases.
Like: if result is between 1 and 50, add 1.
If result is between 51 and 99, add 2 to the end.
If result is between 100 and 200, add 3 to the end.
Like:
Result = 25, do it 251.
Result 67, do it 672.
Result is 150, do it 1503.
I have created a table but the cases don't seem to work. How would I add a digit in specific cases?
CREATE TABLE Numbers(
Num INT
);
INSERT Numbers VALUES('12');
INSERT Numbers VALUES('112');
INSERT Numbers VALUES('12');
INSERT Numbers VALUES('122');
INSERT Numbers VALUES('1');
INSERT Numbers VALUES('2');
INSERT Numbers VALUES('12345678');
INSERT Numbers VALUES('12345');
SELECT * FROM Numbers;
SELECT RIGHT('15'+ CONVERT(VARCHAR,Num),6) AS NUM FROM Numbers;
SELECT LEFT(REPLICATE('0', 10) + CONVERT(VARCHAR, Num), 6) AS NUM FROM Numbers;
SELECT RIGHT('0' + CAST(Num AS VARCHAR(2)), 2) FROM Numbers
SELECT
CASE
WHEN Num BETWEEN 1 AND 99
THEN LEFT ('00' + CAST(Num AS VARCHAR(2)), 2)
ELSE
CAST(Num AS VARCHAR(10))
END
FROM Numbers
Since you're already using varchar on these values, I'd use concat - which simply mergs strings together. In this case you simply select what you want to merge, with what. Documentation on Concat() here.
Fiddle: https://www.db-fiddle.com/f/at2fqinuEao3b8coRSydTD/1
SELECT
CASE WHEN Num BETWEEN 1 AND 50
THEN concat(Num, '1')
WHEN Num BETWEEN 51 AND 99
THEN concat(Num, '2')
WHEN Num BETWEEN 100 AND 199
THEN concat(Num, '3')
ELSE Num END AS Num
FROM Numbers
In the examples of your 25,67 and 150 - this is the result:
Num
251
672
1503
You're working with numbers, so you can do Num*10 + 1 etc. Like this. fiddle
SELECT CASE WHEN Num BETWEEN 1 AND 50 THEN Num*10 + 1
WHEN Num BETWEEN 51 AND 99 THEN Num*10 + 2
WHEN Num BETWEEN 100 AND 199 THEN Num*10 + 3
ELSE Num END AS Num
FROM Numbers
That seems like it might be easier than string-casting and concatenating.
But you could do this if you really want strings. fiddle.
SELECT CASE WHEN Num BETWEEN 1 AND 50 THEN CONCAT(Num, '1')
WHEN Num BETWEEN 51 AND 99 THEN CONCAT(Num, '2')
WHEN Num BETWEEN 100 AND 199 THEN CONCAT(Num, '3')
ELSE CONVERT(Num, CHAR) END AS Num
FROM Numbers

mysql between show matched value

I have a table with columns showing ranges, like
id from to
1 10 100
2 200 300
I have a query which will be a list of values, like 17, 20, 44, 288 etc.
Is it possible to have a result set which would include the where condition, so I get:
id from to input
1 10 100 7
1 10 100 20
1 10 100 144
2 200 300 288
Right now the code runs one query per where value and it works, and I'm looking to increase performance by combing it into one large multiple where clause, like
SELECT *
FROM table
WHERE (from<=7 AND start>=7)
OR (from<=20 AND start>=20)
OR (from<=144 AND start>=144)
OR (from<=288 AND start>=288)
What you want makes no sense regarding ranges.
7 and 144 has no compatible range yet you want to put then into the first range.
In a result set with lots of values listing you will probably get to many conditions.
What you can do is to put those values that isn't in a range to show without correspondence. Like this:
With the structure being:
create table test (
id integer,
vfrom integer,
vto integer
);
insert into test values
(1, 10, 100),
(2, 200, 300);
create table vals(
val integer
);
insert into vals values (7), (20), (144), (288);
You can use this query:
select val, id, vfrom, vto
from vals v left join
test t on ( t.vfrom <= v.val and t.vto >= v.val )
It will bring you:
7 null null null
20 1 10 100
144 null null null
288 2 200 300
see it here on fiddle: http://sqlfiddle.com/#!2/f68fd/8
Maybe it isn't what you want but it is more logical.
Sure there is a query for this. Trouble is we need a table for specific values to show up; and then there are sub-queries and union selects:
SELECT table.*, values.val AS input
FROM (SELECT 7 AS val UNION SELECT 20 AS val UNION SELECT 144 AS val UNION SELECT 288 AS val) as values
JOIN table ON table.from <= values.val AND table.to >= values.val
This should do the trick. Note that you only have to specify the column name in the first SELECT with in a UNION SELECT.
I will suppose you are using Java as your application language. You could build your query this way:
public String buildQuery(int[] myList) {
String queryToReturn = "";
for (int queryIndex = 0; queryIndex < myList.length; queryIndex++) {
queryToReturn += ((queryIndex == 0) ? ("") : (" union ")) +
"(select `id`, `from`, `to`, " + myList[queryIndex] + " as input
from MyTable
where `from` < " + myList[queryIndex] + " and " + myList[queryIndex] " < `to`)";
}
return queryToReturn;
}
Then run the returned query.

Calculate average of some columns, not counting null values

I have a table with some readings that looks like this:
id foo bar baz qux
1 2 4 NULL 3
2 6 11 0 2
I want to calculate an average of some columns, not including null values in the count. Something like this pseudo-code:
select (foo+bar+baz)/countNonNulls(foo,bar,baz) AS result
FROM readings WHERE id=1;
I.e, my expected result is (2+4)/2 = 3.
Is there a way to do this in a single SQL query?
In MySQL, you can use:
select (coalesce(foo, 0) + coalesce(bar, 0) + coalesce(baz, 0) /
((foo is not null) + (bar is not null) + (baz is not null))
) as average
Note that this assumes that at least one value is not null, to prevent division by 0.
To handle the general case, you can use case:
select (case when coalesce(foo, bar, bz) is not null
then (coalesce(foo, 0) + coalesce(bar, 0) + coalesce(baz, 0) /
((foo is not null) + (bar is not null) + (baz is not null))
)
end) as average
try the where clause: where [nameColumn] is not null

can i do this? if( 2<a<8 , 1, 0) as Value in mysql?

I know i can do this
if( a<8 , 1, 0) as Value
but can i do this?
if( 2<a<8 , 1, 0) as Value in mysql ?
I have tired, it doesn't work. if i want to get the 2nd result is there a way to do ?
Sure, you can, but it doesn't give you the result you're hoping for. Perfectly valid, however.
Example:
SELECT IF(1 < 2 < 3, 1, 0) AS `value`
This returns '1'. It must work, right? Not really. What happens is the following:
Is 1 < 2 ? Sure! Let's return "1" (an INT because MySQL doesn't have a boolean TRUE)
Is 1 < 3 ? Sure!
So what happens when we do this?
SELECT IF(100 < 200 < 100) AS `value`
Well.. That's TRUE (1) as well. Because this happens:
Is 100 < 200? Sure! So let's return "1".
Is 1 < 100? Yep!
To be more standardized, I'd write this with a CASE statement:
CASE WHEN a > 2 AND a < 8 THEN 1 ELSE 0 END AS Value
I don't think so, but you can IF( 2<a AND a<8, 1, 0)
SELECT IF (a BETWEEN 3 AND 7, 1, 0) AS Value
Technically you could just use SELECT a BETWEEN 3 AND 7 as this will return 1 or 0 anyway.
Using 3 and 7 because you want > 2 and < 8 not >= 2 and <= 8.
Your example will evaluate 2 < a which returns 0 or 1 depending on the value of a. Then it evaluates 0 < 8 or 1 < 8, which will always evaluate to 1.

MySQL 'Order By' - sorting alphanumeric correctly

I want to sort the following data items in the order they are presented below (numbers 1-12):
1
2
3
4
5
6
7
8
9
10
11
12
However, my query - using order by xxxxx asc sorts by the first digit above all else:
1
10
11
12
2
3
4
5
6
7
8
9
Any tricks to make it sort more properly?
Further, in the interest of full disclosure, this could be a mix of letters and numbers (although right now it is not), e.g.:
A1
534G
G46A
100B
100A
100JE
etc....
Thanks!
update: people asking for query
select * from table order by name asc
People use different tricks to do this. I Googled and find out some results each follow different tricks. Have a look at them:
Alpha Numeric Sorting in MySQL
Natural Sorting in MySQL
Sorting of numeric values mixed with alphanumeric values
mySQL natural sort
Natural Sort in MySQL
Edit:
I have just added the code of each link for future visitors.
Alpha Numeric Sorting in MySQL
Given input
1A 1a 10A 9B 21C 1C 1D
Expected output
1A 1C 1D 1a 9B 10A 21C
Query
Bin Way
===================================
SELECT
tbl_column,
BIN(tbl_column) AS binray_not_needed_column
FROM db_table
ORDER BY binray_not_needed_column ASC , tbl_column ASC
-----------------------
Cast Way
===================================
SELECT
tbl_column,
CAST(tbl_column as SIGNED) AS casted_column
FROM db_table
ORDER BY casted_column ASC , tbl_column ASC
Natural Sorting in MySQL
Given input
Table: sorting_test
-------------------------- -------------
| alphanumeric VARCHAR(75) | integer INT |
-------------------------- -------------
| test1 | 1 |
| test12 | 2 |
| test13 | 3 |
| test2 | 4 |
| test3 | 5 |
-------------------------- -------------
Expected Output
-------------------------- -------------
| alphanumeric VARCHAR(75) | integer INT |
-------------------------- -------------
| test1 | 1 |
| test2 | 4 |
| test3 | 5 |
| test12 | 2 |
| test13 | 3 |
-------------------------- -------------
Query
SELECT alphanumeric, integer
FROM sorting_test
ORDER BY LENGTH(alphanumeric), alphanumeric
Sorting of numeric values mixed with alphanumeric values
Given input
2a, 12, 5b, 5a, 10, 11, 1, 4b
Expected Output
1, 2a, 4b, 5a, 5b, 10, 11, 12
Query
SELECT version
FROM version_sorting
ORDER BY CAST(version AS UNSIGNED), version;
Just do this:
SELECT * FROM table ORDER BY column `name`+0 ASC
Appending the +0 will mean that:
0,
10,
11,
2,
3,
4
becomes :
0,
2,
3,
4,
10,
11
I hate this, but this will work
order by lpad(name, 10, 0) <-- assuming maximum string length is 10
<-- you can adjust to a bigger length if you want to
I know this post is closed but I think my way could help some people. So there it is :
My dataset is very similar but is a bit more complex. It has numbers, alphanumeric data :
1
2
Chair
3
0
4
5
-
Table
10
13
19
Windows
99
102
Dog
I would like to have the '-' symbol at first, then the numbers, then the text.
So I go like this :
SELECT name, (name = '-') boolDash, (name = '0') boolZero, (name+0 > 0) boolNum
FROM table
ORDER BY boolDash DESC, boolZero DESC, boolNum DESC, (name+0), name
The result should be something :
-
0
1
2
3
4
5
10
13
99
102
Chair
Dog
Table
Windows
The whole idea is doing some simple check into the SELECT and sorting with the result.
This works for type of data:
Data1,
Data2, Data3 ......,Data21. Means "Data" String is common in all rows.
For ORDER BY ASC it will sort perfectly, For ORDER BY DESC not suitable.
SELECT * FROM table_name ORDER BY LENGTH(column_name), column_name ASC;
I had some good results with
SELECT alphanumeric, integer FROM sorting_test ORDER BY CAST(alphanumeric AS UNSIGNED), alphanumeric ASC
This type of question has been asked previously.
The type of sorting you are talking about is called "Natural Sorting".
The data on which you want to do sort is alphanumeric.
It would be better to create a new column for sorting.
For further help check
natural-sort-in-mysql
If you need to sort an alpha-numeric column that does not have any standard format whatsoever
SELECT * FROM table ORDER BY (name = '0') DESC, (name+0 > 0) DESC, name+0 ASC, name ASC
You can adapt this solution to include support for non-alphanumeric characters if desired using additional logic.
This should sort alphanumeric field like:
1/ Number only, order by 1,2,3,4,5,6,7,8,9,10,11 etc...
2/ Then field with text like: 1foo, 2bar, aaa11aa, aaa22aa, b5452 etc...
SELECT MyField
FROM MyTable
order by
IF( MyField REGEXP '^-?[0-9]+$' = 0,
9999999999 ,
CAST(MyField AS DECIMAL)
), MyField
The query check if the data is a number, if not put it to 9999999999 , then order first on this column, then order on data with text
Good luck!
Instead of trying to write some function and slow down the SELECT query, I thought of another way of doing this...
Create an extra field in your database that holds the result from the following Class and when you insert a new row, run the field value that will be naturally sorted through this class and save its result in the extra field. Then instead of sorting by your original field, sort by the extra field.
String nsFieldVal = new NaturalSortString(getFieldValue(), 4).toString()
The above means:
- Create a NaturalSortString for the String returned from getFieldValue()
- Allow up to 4 bytes to store each character or number (4 bytes = ffff = 65535)
| field(32) | nsfield(161) |
a1 300610001
String sortString = new NaturalSortString(getString(), 4).toString()
import StringUtils;
/**
* Creates a string that allows natural sorting in a SQL database
* eg, 0 1 1a 2 3 3a 10 100 a a1 a1a1 b
*/
public class NaturalSortString {
private String inStr;
private int byteSize;
private StringBuilder out = new StringBuilder();
/**
* A byte stores the hex value (0 to f) of a letter or number.
* Since a letter is two bytes, the minimum byteSize is 2.
*
* 2 bytes = 00 - ff (max number is 255)
* 3 bytes = 000 - fff (max number is 4095)
* 4 bytes = 0000 - ffff (max number is 65535)
*
* For example:
* dog123 = 64,6F,67,7B and thus byteSize >= 2.
* dog280 = 64,6F,67,118 and thus byteSize >= 3.
*
* For example:
* The String, "There are 1000000 spots on a dalmatian" would require a byteSize that can
* store the number '1000000' which in hex is 'f4240' and thus the byteSize must be at least 5
*
* The dbColumn size to store the NaturalSortString is calculated as:
* > originalStringColumnSize x byteSize + 1
* The extra '1' is a marker for String type - Letter, Number, Symbol
* Thus, if the originalStringColumn is varchar(32) and the byteSize is 5:
* > NaturalSortStringColumnSize = 32 x 5 + 1 = varchar(161)
*
* The byteSize must be the same for all NaturalSortStrings created in the same table.
* If you need to change the byteSize (for instance, to accommodate larger numbers), you will
* need to recalculate the NaturalSortString for each existing row using the new byteSize.
*
* #param str String to create a natural sort string from
* #param byteSize Per character storage byte size (minimum 2)
* #throws Exception See the error description thrown
*/
public NaturalSortString(String str, int byteSize) throws Exception {
if (str == null || str.isEmpty()) return;
this.inStr = str;
this.byteSize = Math.max(2, byteSize); // minimum of 2 bytes to hold a character
setStringType();
iterateString();
}
private void setStringType() {
char firstchar = inStr.toLowerCase().subSequence(0, 1).charAt(0);
if (Character.isLetter(firstchar)) // letters third
out.append(3);
else if (Character.isDigit(firstchar)) // numbers second
out.append(2);
else // non-alphanumeric first
out.append(1);
}
private void iterateString() throws Exception {
StringBuilder n = new StringBuilder();
for (char c : inStr.toLowerCase().toCharArray()) { // lowercase for CASE INSENSITIVE sorting
if (Character.isDigit(c)) {
// group numbers
n.append(c);
continue;
}
if (n.length() > 0) {
addInteger(n.toString());
n = new StringBuilder();
}
addCharacter(c);
}
if (n.length() > 0) {
addInteger(n.toString());
}
}
private void addInteger(String s) throws Exception {
int i = Integer.parseInt(s);
if (i >= (Math.pow(16, byteSize)))
throw new Exception("naturalsort_bytesize_exceeded");
out.append(StringUtils.padLeft(Integer.toHexString(i), byteSize));
}
private void addCharacter(char c) {
//TODO: Add rest of accented characters
if (c >= 224 && c <= 229) // set accented a to a
c = 'a';
else if (c >= 232 && c <= 235) // set accented e to e
c = 'e';
else if (c >= 236 && c <= 239) // set accented i to i
c = 'i';
else if (c >= 242 && c <= 246) // set accented o to o
c = 'o';
else if (c >= 249 && c <= 252) // set accented u to u
c = 'u';
else if (c >= 253 && c <= 255) // set accented y to y
c = 'y';
out.append(StringUtils.padLeft(Integer.toHexString(c), byteSize));
}
#Override
public String toString() {
return out.toString();
}
}
For completeness, below is the StringUtils.padLeft method:
public static String padLeft(String s, int n) {
if (n - s.length() == 0) return s;
return String.format("%0" + (n - s.length()) + "d%s", 0, s);
}
The result should come out like the following
-1
-a
0
1
1.0
1.01
1.1.1
1a
1b
9
10
10a
10ab
11
12
12abcd
100
a
a1a1
a1a2
a-1
a-2
áviacion
b
c1
c2
c12
c100
d
d1.1.1
e
MySQL ORDER BY Sorting alphanumeric on correct order
example:
SELECT `alphanumericCol` FROM `tableName` ORDER BY
SUBSTR(`alphanumericCol` FROM 1 FOR 1),
LPAD(lower(`alphanumericCol`), 10,0) ASC
output:
1
2
11
21
100
101
102
104
S-104A
S-105
S-107
S-111
This is from tutorials point
SELECT * FROM yourTableName ORDER BY
SUBSTR(yourColumnName FROM 1 FOR 2),
CAST(SUBSTR(yourColumnName FROM 2) AS UNSIGNED);
it is slightly different from another answer of this thread
For reference, this is the original link
https://www.tutorialspoint.com/mysql-order-by-string-with-numbers
Another point regarding UNSIGNED is written here
https://electrictoolbox.com/mysql-order-string-as-int/
While this has REGEX too
https://www.sitepoint.com/community/t/how-to-sort-text-with-numbers-with-sql/346088/9
SELECT length(actual_project_name),actual_project_name,
SUBSTRING_INDEX(actual_project_name,'-',1) as aaaaaa,
SUBSTRING_INDEX(actual_project_name, '-', -1) as actual_project_number,
concat(SUBSTRING_INDEX(actual_project_name,'-',1),SUBSTRING_INDEX(actual_project_name, '-', -1)) as a
FROM ctts.test22
order by
SUBSTRING_INDEX(actual_project_name,'-',1) asc,cast(SUBSTRING_INDEX(actual_project_name, '-', -1) as unsigned) asc
This is a simple example.
SELECT HEX(some_col) h
FROM some_table
ORDER BY h
order by len(xxxxx),xxxxx
Eg:
SELECT * from customer order by len(xxxxx),xxxxx
Try this For ORDER BY DESC
SELECT * FROM testdata ORDER BY LENGHT(name) DESC, name DESC
SELECT
s.id, s.name, LENGTH(s.name) len, ASCII(s.name) ASCCCI
FROM table_name s
ORDER BY ASCCCI,len,NAME ASC;
Assuming varchar field containing number, decimal, alphanumeric and string, for example :
Let's suppose Column Name is "RandomValues" and Table name is "SortingTest"
A1
120
2.23
3
0
2
Apple
Zebra
Banana
23
86.Akjf9
Abtuo332
66.9
22
ABC
SELECT * FROM SortingTest order by IF( RandomValues REGEXP '^-?[0-9,.]+$' = 0,
9999999999 ,
CAST(RandomValues AS DECIMAL)
), RandomValues
Above query will do sorting on number & decimal values first and after that all alphanumeric values got sorted.
This will always put the values starting with a number first:
ORDER BY my_column REGEXP '^[0-9]' DESC, length(my_column + 0), my_column ";
Works as follows:
Step1 - Is first char a digit? 1 if true, 0 if false, so order by this DESC
Step2 - How many digits is the number? Order by this ASC
Step3 - Order by the field itself
Input:
('100'),
('1'),
('10'),
('0'),
('2'),
('2a'),
('12sdfa'),
('12 sdfa'),
('Bar nah');
Output:
0
1
2
2a
10
12 sdfa
12sdfa
100
Bar nah
Really problematic for my scenario...
select * from table order by lpad(column, 20, 0)
My column is a varchar, but has numeric input (1, 2, 3...) , mixed numeric (1A, 1B, 1C) and too string data (INT, SHIP)