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How to create composite primary key in SQL Server 2008
...
create table my_table (
column_a integer not null,
column_b integer not null,
column_c varchar(50),
primary key (column_a, column_b)
);
share
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Detect encoding and make everything UTF-8
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If you apply utf8_encode() to an already UTF-8 string, it will return garbled UTF-8 output.
I made a function that addresses all this issues. It´s called Encoding::toUTF8().
You don't need to know what the encoding of your strings is. It c...
Setting variable to NULL after free
... only not best practice, it's wrong. For example: foo* bar=getFoo(); /*more_code*/ free(bar); /*more_code*/ return bar != NULL;. Here, setting bar to NULL after the call to free will cause the function to think it never had a bar and return the wrong value!
– David Schwartz
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Hidden Features of MySQL
...he SQL queries to guide MySQL to execute them faster.
Administration:
max_connections is the number of concurrent connections. The default value is 100 connections (151 since 5.0) - very small.
Note:
connections take memory and your OS might not be able to handle a lot of connections.
MySQL b...
find filenames NOT ending in specific extensions on Unix?
...ing like this:
## data section, list undesired extensions here
declare -a _BADEXT=(xml dll)
## code section, this never changes
BADEXT="$( IFS="|" ; echo "${_BADEXT[*]}" | sed 's/|/\\|/g' )"
find . -type f ! -regex ".*\.\($BADEXT\)"
Which results in:
./a/1.txt
./a/b/2.txt
./a/b/c/3.txt
./a/d/4....
Convert seconds to Hour:Minute:Second
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here you go
function format_time($t,$f=':') // t = seconds, f = separator
{
return sprintf("%02d%s%02d%s%02d", floor($t/3600), $f, ($t/60)%60, $f, $t%60);
}
echo format_time(685); // 00:11:25
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Measure and Benchmark Time for Ruby Methods
...justments to the system clock, so it's a best practice to use Process.clock_gettime(Process::CLOCK_MONOTONIC) instead. But for rough calculations this doesn't matter. blog.dnsimple.com/2018/03/elapsed-time-with-ruby-the-right-way
– Patrick Brinich-Langlois
Feb ...
How to return an array from JNI to Java?
...ode is going to look something like this:
JNIEXPORT jintArray JNICALL Java_ArrayTest_initIntArray(JNIEnv *env, jclass cls, int size)
{
jintArray result;
result = (*env)->NewIntArray(env, size);
if (result == NULL) {
return NULL; /* out of memory error thrown */
}
int i;
// fill a temp...
Why does the 260 character path length limit exist in Windows?
...iscussed in the following paragraphs), the maximum length for a path is MAX_PATH, which is defined as 260 characters. A local path is structured in the following order: drive letter, colon, backslash, name components separated by backslashes, and a terminating null character. For example, the maximu...
Does order of where clauses matter in SQL?
...nswered Jul 11 '12 at 15:50
marc_smarc_s
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