Introduction
In this article I describe the PHP MySQLi functions mysqli_debug, mysqli_dump_debug_info, mysqli_errno, mysqli__error_list and mysqli-error. To learn some other MySQLi functions, go to:
- MySQLi Function in PHP: Part 1
- MySQLi Function in PHP: Part 2
PHP mysqli_debug() Function
The PHP MySQLi mysqli_debug function performs debugging operations and this function returns true.
Syntax
Parameter of the mysqli_debug function
The parameter of the function is:
Parameter |
Description |
message |
It specifies a string that represents the debugging operation to perform. |
Example
The following example creates a trace file in "/tmp/client.trace" on the local (client) machine.
<?php
mysqli_debug("d:t:o,/temp/client.trace");
?>
PHP mysqli_dump_debug_info() Function
The PHP MySQLi "mysqli_debug" function dumps debugging information into the log and this function returns true on success or false on failure.
Syntax
mysql_dump_debug_info(link) |
Parameter of the mysqli_dump_debug_info function
The parameter of the function is:
Parameter |
Description |
link |
It specifies a link identifier returned by mysqli_connect() or mysqli_init() function. |
Example
An example of the function is:
<?php
$con=mysqli_connect("localhost","root","","mysql");
if (mysqli_connect_error($con))
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
mysqli_dump_debug_info($con);
mysqli_close($con);
?>
PHP mysqli_errno() Function
The PHP MySQLi "mysqli_errno" function returns the last error code for the most recent function call or in other words this function returns an error value of the last call, if it failed otherwise it returns zero, meaning that no error occured.
Syntax
Parameter of the mysqli_errno function
The parameter of the function is:
Parameter |
Description |
connection |
It specifies the MySQL connection to use. |
Example
An example of the function is:
<?php
$con=mysqli_connect("localhost","root","","mysql");
if (mysqli_connect_error($con))
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
if (!mysqli_query($con,"INSERT INTO emp (id,name,salary) VALUES (101,'Rahul',667897)")) //error free
{
echo("Errorcode: " . mysqli_errno($con));
}
/*........For Fetch data of Emp Table<br>
.......*/
print "<h2>MySQL: Data of Emp table</h2>";
$result =mysqli_query($con,"SELECT * FROM emp");
echo "<table border='1'>
<tr>
<th>Id</th>
<th>Name</th>
<th>Salary</th>
</tr>";
while($rowval = mysqli_fetch_array($result))
{
echo "<tr>";
echo "<td>" . $rowval['id'] . "</td>";
echo "<td>" . $rowval['name'] . "</td>";
echo "<td>" . $rowval['salary'] . "</td>";
echo "</tr>";
}
echo "</table>";
/*........For Fetch data of Emp Table<br>
.......*/
print "<h2>Write a query with error:</h2>";
if (!mysqli_query($con,"INSERT INTO emp (id,name,salary) VALUES (109,'Rahul',667897,'admin')"))
{
//I try to insert "admin" as a role in "emp" table, and that column is not there.
echo("Errorcode: " . mysqli_errno($con));
}
mysqli_close($con);
?>
Output
PHP mysqli_error_list() Function
The PHP MySQLi "mysqli_errorlist" function returns a list of errors from the last command executed or in other words this function returns a list of errors, each as an associative array containing the errno, error, and sqlstate.
Syntax
mysql_error_list(connection) |
Parameter of the mysqli_error_list function
The parameter of the function is:
Parameter |
Description |
connection |
It specifies MySQL connection to use. |
Example
An example of the function is:
<?php
$con=mysqli_connect("localhost","root","","mysql");
if (mysqli_connect_error($con))
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
if (!mysqli_query($con,"INSERT INTO emp (id,name,salary) VALUES (107,'Sumit',654675)")) //error free
{
print_r(mysqli_error_list($con));
}
/*........For Fetch data of Emp Table<br>
.......*/
print "<h2>MySQL: Data of Emp table</h2>";
$result =mysqli_query($con,"SELECT * FROM emp");
echo "<table border='1'>
<tr>
<th>Id</th>
<th>Name</th>
<th>Salary</th>
</tr>";
while($rowval = mysqli_fetch_array($result))
{
echo "<tr>";
echo "<td>" . $rowval['id'] . "</td>";
echo "<td>" . $rowval['name'] . "</td>";
echo "<td>" . $rowval['salary'] . "</td>";
echo "</tr>";
}
echo "</table>";
/*........For Fetch data of Emp Table<br>
.......*/
print "<h2>Write a query with error:</h2>";
if (!mysqli_query($con,"INSERT INTO emp (id,name,salary) VALUES (107,'Sumit',654675,'admin')"))
{
print_r(mysqli_error_list($con));
}
mysqli_close($con);
?>
Output
PHP mysqli_error() Function
The PHP MySQLi "mysqli_error" function returns a string description of the last error or in other words this function returns a string that describes the error or returns an empty string if no error occured.
Syntax
Parameter of the mysqli_error function
The parameter of the function is:
Parameter |
Description |
connection |
It specifies the MySQL connection to use. |
Example
An example of the function is:
<?php
$con=mysqli_connect("localhost","root","","mysql");
if (mysqli_connect_errno($con))
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
print "<h2>Write a query with error:</h2>";
if (!mysqli_query($con,"INSERT INTO emp (id,name,salary) VALUES (107,'Sumit',654675,'admin')"))
{
echo("Errorcode: " . mysqli_error($con));
}
mysqli_close($con);
?>
Output