大约有 48,000 项符合查询结果（耗时：0.0624秒） [XML]
What's the difference between HEAD^ and HEAD~ in Git?
When I specify an ancestor commit object in Git, I'm confused between HEAD^ and HEAD~ .
15 Answers
...
Increment a database field by 1
With MySQL, if I have a field, of say logins, how would I go about updating that field by 1 within a sql command?
5 Answers...
How to check whether a string contains a substring in Ruby
...
You can use the include? method:
my_string = "abcdefg"
if my_string.include? "cde"
puts "String includes 'cde'"
end
share
|
improve this answer
|
foll...
How do you connect to multiple MySQL databases on a single webpage?
...elow from @Troelskn
You can make multiple calls to mysql_connect(), but if the parameters are the same you need to pass true for the '$new_link' (fourth) parameter, otherwise the same connection is reused. For example:
$dbh1 = mysql_connect($hostname, $username, $password);
$dbh2 = mysql_connec...
memory_get_peak_usage() with “real usage”
If the real_usage argument is set to true the PHP DOCS say it will get the real size of memory allocated from system. If it's false it will get the memory reported by emalloc()
...
Test if string is a guid without throwing exceptions?
...return will contain the Guid</param>
/// <returns>Returns true if successful, otherwise false</returns>
public static Boolean TryStrToGuid(String s, out Guid value)
{
//ClsidFromString returns the empty guid for null strings
if ((s == null) || (s == ""))
{
...
Test if a vector contains a given element
How to check if a vector contains a given value?
7 Answers
7
...
How do I perform an IF…THEN in an SQL SELECT?
How do I perform an IF...THEN in an SQL SELECT statement?
30 Answers
30
...
Error in if/while (condition) {: missing Value where TRUE/FALSE needed
...
The evaluation of condition resulted in an NA. The if conditional must have either a TRUE or FALSE result.
if (NA) {}
## Error in if (NA) { : missing value where TRUE/FALSE needed
This can happen accidentally as the results of calculations:
if(TRUE && sqrt(-1)) ...
SQL SELECT WHERE field contains words
...LIKE '%word1%'
OR column1 LIKE '%word2%'
OR column1 LIKE '%word3%'
If you need all words to be present, use this:
SELECT * FROM mytable
WHERE column1 LIKE '%word1%'
AND column1 LIKE '%word2%'
AND column1 LIKE '%word3%'
If you want something faster, you need to look into full text sear...