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How to change column datatype from character to numeric in PostgreSQL 8.4
...nding on your data):
alter table presales alter column code type numeric(10,0) using code::numeric;
-- Or if you prefer standard casting...
alter table presales alter column code type numeric(10,0) using cast(code as numeric);
This will fail if you have anything in code that cannot be cast to num...
Mod of negative number is melting my brain
...ould write it as
int mod(int x, int m) {
int r = x%m;
return r<0 ? r+m : r;
}
or variants thereof.
The reason it works is that "x%m" is always in the range [-m+1, m-1]. So if at all it is negative, adding m to it will put it in the positive range without changing its value modulo m.
...
Guards vs. if-then-else vs. cases in Haskell
...and guards should almost always be used instead.
let absOfN =
if n < 0 -- Single binary expression
then -n
else n
Every if..then..else expression can be replaced by a guard if it is at the top level of a function, and this should generally be preferred, since you can add more cases more...
Handling Touch Event in UILabel and hooking it up to an IBAction
...
Scott PersingerScott Persinger
3,46022 gold badges1717 silver badges1010 bronze badges
...
How to check if PHP array is associative or sequential?
...w to determine whether an array has sequential numeric keys, starting from 0
Consider which of these behaviours you actually need. (It may be that either will do for your purposes.)
The first question (simply checking that all keys are numeric) is answered well by Captain kurO.
For the second qu...
How to make gradient background in android
...
answered Dec 18 '12 at 10:11
Gunnar KarlssonGunnar Karlsson
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...
How do I rename all files to lowercase?
...
answered Oct 16 '11 at 20:39
wjlwjl
6,29011 gold badge2828 silver badges4646 bronze badges
...
How do I break out of a loop in Scala?
...f loops.
Suppose you want to sum numbers until the total is greater than 1000. You try
var sum = 0
for (i <- 0 to 1000) sum += i
except you want to stop when (sum > 1000).
What to do? There are several options.
(1a) Use some construct that includes a conditional that you test.
var sum...
How are cookies passed in the HTTP protocol?
...
302
The server sends the following in its response header to set a cookie field.
Set-Cookie:name=v...
App Inventor 2 Web客户端（Web）详细用法示例 · App Inventor 2 中文网
...网IP:8768/upload。
中途验证：电脑浏览器打开 http://127.0.0.1:8768/，看到 {"uploads": []}。
第 2 步：确认手机连得到电脑
查电脑的局域网 IP（Windows 运行 ipconfig 看「IPv4 地址」，macOS/Linux 运行 ifconfig 或 ip addr），例如 192.168.1.23。
...