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The usleep() function delays execution of the current script for few microseconds.Syntaxusleep(msec)Parametersmsec − The number of microseconds to delay the script.ReturnThe usleep() function returns nothing.Example Live DemoOutputThe following is the output.03:06:08 03:06:10 03:06:15
The unpack() function unpacks data from a binary string.Syntaxunpack(format, data)Parametersformat − The format to use. Here are the possible valuesa −NUL-padded stringA − SPACE-padded stringh − Hex string, low nibble firstH − Hex string, high nibble firstc − signed charC −unsigned chars − signed short (always 16 bit, machine byte order)S − unsigned short (always 16 bit, machine byte order)n − unsigned short (always 16 bit, big endian byte order)v − unsigned short (always 16 bit, little endian byte order)i − signed integer (machine dependent size and byte order)I − unsigned integer (machine dependent size and byte order)l − signed ... Read More
The uniqid() function generates a unique ID based on the current time in microseconds.Syntaxuniqid(prefix, more_entropy)Parametersprefix − The prefix to the unique ID.more_entropy − The more entropy at the end of the return value.ReturnThe uniqid() function returns unique identifiers as string.Example Live DemoOutputThe following is the output.5bfd5bd045faa
For this, you can use UNION ALL along with WHERE NOT EXISTS and implement NOT IN to ignore the values already in the table. Use SELECT with UNION ALL to add values not already in the table.Let us first create a table −mysql> create table DemoTable1918 ( Value int NOT NULL AUTO_INCREMENT PRIMARY KEY ); Query OK, 0 rows affected (0.00 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1918 values(); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1918 values(); Query OK, 1 row affected (0.00 sec) mysql> insert into ... Read More
To parse a CSV file in PHP, the code is as follows. Under fopen(), set the path of the .csv file−Example$row_count = 1; if (($infile = fopen("path to .csv file", "r")) !== FALSE) { while (($data_in_csv = fgetcsv($infile, 800, ", ")) !== FALSE) { $data_count = count($data_in_csv); echo " $data_count in line $row_count: "; $row_count++; for ($counter=0; $counter < $data_count; $counter++) { echo $$data_in_csv[$counter] . ""; } } fclose(infile); }Code explanation − The file can be opened in reading ... Read More
To get all rows apart from first and last, use subquery along with MIN() and MAX(). Let us first create a table −mysql> create table DemoTable1917 ( StudentId int NOT NULL AUTO_INCREMENT PRIMARY KEY, StudentCode int, StudentMarks int ); Query OK, 0 rows affected (0.00 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1917(StudentCode, StudentMarks) values(78, 95); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1917(StudentCode, StudentMarks) values(78, 96); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1917(StudentCode, StudentMarks) values(78, 97); Query OK, 1 row affected (0.00 ... Read More
The 'foreach' is slow in comparison to the 'for' loop. The foreach copies the array over which the iteration needs to be performed.For improved performance, the concept of references needs to be used. In addition to this, ‘foreach’ is easy to use.ExampleBelow is a simple code example − Live DemoOutputThis will produce the following output −This completed in 0.00058293342590332 seconds This completed in 0.00063300132751465 seconds This completed in 0.00023412704467773 seconds This completed in 0.00026583671569824 seconds
For this, set conditions using MySQL CASE statement −mysql> create table DemoTable1916 ( StudentName varchar(20), StudentMarks int ); Query OK, 0 rows affected (0.00 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1916 values('Chris', 59); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1916 values('David', 89); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1916 values('Sam', 94); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1916 values('Mike', 75); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1916 values('Carol', 69); Query OK, 1 row affected ... Read More
The property_exists() or the isset() function can be used to check if the property exists in the class or object.SyntaxBelow is the syntax of property_exists() function−property_exists( mixed $class , string $property )Exampleif (property_exists($object, 'a_property'))Below is the syntax of isset() function−isset( mixed $var [, mixed $... ] )Exampleif (isset($object->a_property))The isset() will return false if the ‘a_property’ is null.ExampleLet us see an example − Live DemoOutputThis will produce the following output−bool(true) bool(true)
The sleep() function delays execution of the current script for short time period.Syntaxsleep(sec)Parameterssec− The number of seconds to delay the script.ReturnThe sleep() function returns zero on success.Example Live DemoOutputThe following is the output.02:54:50 02:54:52 02:54:57