CAST DECIMAL to INT - mysql

Question

I'm trying to do this:
SELECT CAST(columnName AS INT), moreColumns, etc
FROM myTable
WHERE ...
I've looked at the help FAQs here: http://dev.mysql.com/doc/refman/5.0/en/cast-functions.html , it says I can do it like CAST(val AS TYPE), but it's not working.
Trying to convert a decimal to int, real value is 223.00 and I want 223

Answer 1

You could try the FLOOR function like this:
SELECT FLOOR(columnName), moreColumns, etc
FROM myTable
WHERE ...
You could also try the FORMAT function, provided you know the decimal places can be omitted:
SELECT FORMAT(columnName,0), moreColumns, etc
FROM myTable
WHERE ...
You could combine the two functions
SELECT FORMAT(FLOOR(columnName),0), moreColumns, etc
FROM myTable
WHERE ...

Answer 2

A more optimized way in mysql for this purpose*:
SELECT columnName DIV 1 AS columnName, moreColumns, etc
FROM myTable
WHERE ...
Using DIV 1 is a huge speed improvement over FLOOR, not to mention string based functions like FORMAT
(graphic from Roland Bouman's blog)
mysql> SELECT BENCHMARK(10000000,1234567 DIV 7) ;
+-----------------------------------+
| BENCHMARK(10000000,1234567 DIV 7) |
+-----------------------------------+
| 0 |
+-----------------------------------+
1 row in set (0.83 sec)
mysql> SELECT BENCHMARK(10000000,1234567 / 7) ;
+---------------------------------+
| BENCHMARK(10000000,1234567 / 7) |
+---------------------------------+
| 0 |
+---------------------------------+
1 row in set (7.26 sec)
mysql> SELECT BENCHMARK(10000000,FLOOR(1234567 / 7)) ;
+----------------------------------------+
| BENCHMARK(10000000,FLOOR(1234567 / 7)) |
+----------------------------------------+
| 0 |
+----------------------------------------+
1 row in set (8.80 sec)
(*) NOTE: As pointed by Grbts, be aware of the behaviour of DIV 1 when used with non unsigned/positive values.

Answer 3

From the article you linked to:
The type can be one of the following values:
BINARY[(N)]
CHAR[(N)]
DATE
DATETIME
DECIMAL[(M[,D])]
SIGNED [INTEGER]
TIME
UNSIGNED [INTEGER]
Try SIGNED instead of INT

Answer 4

The CAST() function does not support the "official" data type "INT" in MySQL, it's not in the list of supported types. With MySQL, "SIGNED" (or "UNSIGNED") could be used instead:
CAST(columnName AS SIGNED)
However, this seems to be MySQL-specific (not standardized), so it may not work with other databases. At least this document (Second Informal Review Draft) ISO/IEC 9075:1992, Database does not list "SIGNED"/"UNSIGNED" in section 4.4 Numbers.
But DECIMAL is both standardized and supported by MySQL, so the following should work for MySQL (tested) and other databases:
CAST(columnName AS DECIMAL(0))
According to the MySQL docs:
If the scale is 0, DECIMAL values contain no decimal point or
fractional part.

Answer 5

use this
mysql> SELECT TRUNCATE(223.69, 0);
> 223
Here's a link

Answer 6

There is an important difference between floor() and DIV 1. For negative numbers, they behave differently. DIV 1 returns the integer part (as cast as signed does), while floor(x) returns "the largest integer value not greater than x" (from the manual). So : select floor(-1.1) results in -2, while select -1.1 div 1 results in -1

Answer 7

your can try this :
SELECT columnName1, CAST(columnName2 AS SIGNED ) FROM tableName

Answer 8

There's also ROUND() if your numbers don't necessarily always end with .00. ROUND(20.6) will give 21, and ROUND(20.4) will give 20.

Answer 9

Try cast (columnName as unsigned)
unsigned is positive value only
If you want to include negative value, then cast (columnName as signed),
The difference between sign (negative include) and unsigned (twice the size of sign, but non-negative)

Answer 10

1 cent:
no space b/w CAST and (expression).
i.e., CAST(columnName AS SIGNED).