PHP gets the query time method of MySQL executing sql statement

As shown below:

// Timing start 
runtime();
 
// Execute a query 
mysql_query($sql);
 
// End of timing .
echo runtime(1);
 
// Timing function  
function runtime($mode=0) {
 static $t; 
 if(!$mode) { 
  $t = microtime();
  return;
 } 
 $t1 = microtime(); 
 list($m0,$s0) = explode(" ",$t); 
 list($m1,$s1) = explode(" ",$t1); 
 return sprintf("%.3f ms",($s1+$m1-$s0-$m0)*1000);
}

Analyzing the execution time of sql can:

1. Determine whether the writing of sql is reasonable and efficient

2. Check whether the design of fields and tables is reasonable

Method 1: Overwrite the sql operation class at the bottom of the system. Generally, the structure of the class is

Service model--"db Class--" Executes sql

It can be rewritten at a certain stage according to the situation, such as db class; It is usually modified

public function execute($sql) {
 　　 //code...

/* Detection sql Execution time, which is recorded in the log if it exceeds the execution time */
$start_time = array_sum(explode(' ', microtime()));

$this->lastresult = mysql_query($sql,$this->link) or $this->displayerror($sql);

$end_time = array_sum(explode(' ', microtime()));
$differ = $end_time - $start_time;
if($differ >0.001){    // Modification time range in seconds 
 putContent('sqlLOG', date('Y-m-d H:i:s', $start_time)." "
  . date('Y-m-d H:i:s', $end_time)." "
  .$differ. " ".$sql."\r\n");
}


 　　 //code...
}

Quote:

For the code in phpmyadmin, get the execution time of query as follows:

 
// garvin: Measure query time.
// TODO-Item http://sourceforge.net/tracker/index.php?func=detail&aid=571934&group_id=23067&atid=377411

$querytime_before = array_sum(explode(' ', microtime()));
$result = @PMA_DBI_try_query($full_sql_query, null, PMA_DBI_QUERY_STORE);
$querytime_after = array_sum(explode(' ', microtime()));
$GLOBALS['querytime'] = $querytime_after - $querytime_before;

In addition to this way, you can also use profile of mysql.

This is more suitable for counting the implementation of multiple sql.

I have seen what seems to be a blog. After visiting the page, there will be a prompt saying that the database was queried several times and how long it took to query the data, so it can be easily realized to open profile of mysql.

Annotation 1: micortime function

The microsecond function micortime () returns the current UNIX timestamp and the number of microseconds. Returns floating-point numbers in seconds. However, the function is only available on operating systems that support gettimeofday () system calls. You can check the manual for a detailed understanding. Some unknown errors may be caused, so pay attention.

Annotation 2: profile can save up to 100 records. How to solve this problem?

profiling_history_size
The number of statements for which to maintain profiling information if profiling is enabled. The default value is 15. The maximum value is 100. Setting the value to 0 effectively disables profiling.

There are 100 articles at most, so we can't change them.

Reference 2: PHP method for obtaining millisecond timestamp

java can be passed through gettime (); Get. If you want to communicate with some programs written by java in milliseconds with high precision, you need to use PHP to output milliseconds. To get a more accurate millisecond timestamp, you can use the following code:

<?php
function getMillisecond() {
list($t1, $t2) = explode(' ', microtime());
return (float)sprintf('%.0f',(floatval($t1)+floatval($t2))*1000);
}
echo getMillisecond();

Running result: 1.46647658229E +12