There is no internal MySQL command to trace this, it’s a little too abstract. The file might be in 5 (or more?) locations, and they would all be valid because they load cascading. /etc/my.cnf /etc/mysql/my.cnf $MYSQL_HOME/my.cnf [datadir]/my.cnf ~/.my.cnf Those are the default locations MySQL looks at. If it finds more than one, it will load … Read more
Firstly, I am considering my answer to show you another better way for connection with MySQL Database, it’s much easier and less nu-expected Exception(s).You need to do some steps: Download Connector/J and add it to your class path(if you are using an IDE there is add the .jar to the library, or there is many … Read more
If you’re looking for a way to normalize a date into MySQL format, use the following The line $phpdate = strtotime( $mysqldate ) accepts a string and performs a series of heuristics to turn that string into a unix timestamp. The line $mysqldate = date( ‘Y-m-d H:i:s’, $phpdate ) uses that timestamp and PHP’s date … Read more
MySql does not recognise MINUS and INTERSECT, these are Oracle based operations. In MySql a user can use NOT IN as MINUS (other solutions are also there, but I liked it lot). Example:
Escaping a string means to reduce ambiguity in quotes (and other characters) used in that string. For instance, when you’re defining a string, you typically surround it in either double quotes or single quotes: But what if my string had double quotes within it? Now I have ambiguity – the interpreter doesn’t know where my … Read more
Because $newDate is an object of type DateTime, not a string. The documentation is explicit: Returns new DateTime object formatted according to the specified format. If you want to convert from a string to DateTime back to string to change the format, call DateTime::format at the end to get a formatted string out of your DateTime. ShareFollowa
SQL is evaluated backwards, from right to left. So the where clause is parsed and evaluate prior to the select clause. Because of this the aliasing of u_name to user_name has not yet occurred.
At first glance… All you need is a GROUP BY clause with the MAX aggregate function: It’s never that simple, is it? I just noticed you need the content column as well. This is a very common question in SQL: find the whole data for the row with some max value in a column per some group identifier. I heard that … Read more
Just in case anyone still cares: I had the same issue after copying a database directory directly using command If you do this with a database that uses InnoDB tables, you will get this crazy ‘table does not exist’ error mentioned above. The issue is that you need the ib* files in the root of the MySQL datadir (e.g. ibdata1, ib_logfile0 and ib_logfile1). … Read more
This problem consists of two very different sub-problems: the string must be seemingly random the string must be unique While randomness is quite easily achieved, the uniqueness without a retry loop is not. This brings us to concentrate on the uniqueness first. Non-random uniqueness can trivially be achieved with AUTO_INCREMENT. So using a uniqueness-preserving, pseudo-random … Read more