mysqli::debug

mysqli_debug

(PHP 5, PHP 7)

mysqli::debug -- mysqli_debug — Performs debugging operations

说明

面向对象风格

mysqli::debug ( string $message ) : bool

过程化风格

mysqli_debug ( string $message ) : bool

Performs debugging operations using the Fred Fish debugging library.

参数

message

A string representing the debugging operation to perform

返回值

Returns TRUE.

注释

Note:

To use the mysqli_debug() function you must compile the MySQL client library to support debugging.

范例

Example #1 Generating a Trace File

<?php

/* Create a trace file in '/tmp/client.trace' on the local (client) machine: */
mysqli_debug("d:t:o,/tmp/client.trace");

?>

参见

User Contributed Notes

Domenic 14-May-2018 10:17
Looks like this manual could be referred to:

http://tiebing.blogspot.com.au/2011/10/cc-dbug-library.html

(I haven't tested it)
riversnowchang at gmail dot com 03-Jan-2018 02:42
Here are the information about debug options on mysqli_debug()

O,o:MYSQLND_DEBUG_FLUSH
A,a:MYSQLND_DEBUG_APPEND
F:MYSQLND_DEBUG_DUMP_FILE
L:MYSQLND_DEBUG_DUMP_LINE
m:MYSQLND_DEBUG_TRACE_MEMORY_CALLS
n:MYSQLND_DEBUG_DUMP_LEVEL
o:output to file
T:MYSQLND_DEBUG_DUMP_TIME
t:MYSQLND_DEBUG_DUMP_TRACE
x:MYSQLND_DEBUG_PROFILE_CALLS
f:? still investigating

For example, mysqli_debug("T:n:t:m:x:F:L:o,/tmp/client.trace");
mysqlnd will write Time, Level, trace, memory calls, profile calls, File, Line to client.trace file.

22:35:42.704501 ../mysqlnd_connection.c:  269   0:>mysqlnd_connection_init
22:35:42.704538 ../mysqlnd_driver.c:   10   1:| >mysqlnd_driver::get_connection
22:35:42.704549 ../mysqlnd_driver.c:   10   2:| | info : persistent=1
22:35:42.704558 ../mysqlnd_alloc.c:   21   2:| | >_mysqlnd_pecalloc
22:35:42.704570 ../mysqlnd_alloc.c:   23   2:| | <_mysqlnd_pecalloc (total=3 own=3 in_calls=0)
22:35:42.704602 ../mysqlnd_alloc.c:   21   2:| | >_mysqlnd_pecalloc
22:35:42.704626 ../mysqlnd_alloc.c:   23   2:| | <_mysqlnd_pecalloc (total=2 own=2 in_calls=0)
22:35:42.704650 ../mysqlnd_connection.c:   15   2:| | >mysqlnd_error_info_init
22:35:42.704675 ../mysqlnd_connection.c:   10   3:| | | >mysqlnd_error_info::reset
22:35:42.704697 ../mysqlnd_connection.c:   10   3:| | | <mysqlnd_error_info::reset (total=1 own=1 in_calls=0)
22:35:42.704725 ../mysqlnd_connection.c:   16   2:| | <mysqlnd_error_info_init (total=51 own=50 in_calls=1)
22:35:42.704744 ../mysqlnd_connection.c:   21   2:| | >mysqlnd_connection_state_init

If there is anything wrong, please let me know.
Peter 10-May-2014 10:59
can there be more documenation with a small (but working) example script on how to use this ?

Some issues  (Ive seen the "same" code example in dozens of tutorials):-

( I'll use capitals for emphasis only)

QUESTION: what does D:T:O mean ? UNEXPLAINED.

QUESTION: Do we *ONLY* use these 3 lines in a self-contained script ? Does this log ALL future MYSQL commands ?

QUESTION :- Do we put that one line just

- immediately after we connect to MYSQL ?
- before we connect to MYSQL ?
- before our suspected error ?