PHP | mysqli_free_result() Function

PHP mysqli_free_result() Function


Hello folks! welcome back to a new edition of our tutorial on PHP. In this tutorial guide, we are going to be studying about the PHP mysqli_free_result() Function.

The mysqli_free_result() function accepts a result object as a parameter and frees the memory associated with it.

Syntax

Following below is the syntax to use this function -

mysqli_free_result($result);


Parameter Details

Sr.NoParameter & Description
1

result(Mandatory)

This is an identifier representing a result object.


Return Value

This built-in PHP function does not return any values.

PHP Version

This PHP function was first introduced in PHP version 5 and works in all the later versions.

Example1

The following below is an example which demonstrates the usage of PHP mysqli_free_result() function (in a procedural style) -

<?php
   $con = mysqli_connect("localhost", "root", "password", "mydb");

   mysqli_query($con, "CREATE TABLE myplayers(ID INT, First_Name VARCHAR(255), Last_Name VARCHAR(255), Place_Of_Birth VARCHAR(255), Country VARCHAR(255))");
   print("Table Created.....\n");
   mysqli_query($con, "INSERT INTO myplayers values(1, 'Kennedy', 'Nkpara', 'PortHarcourt', 'Nigeria')");
   mysqli_query($con, "INSERT INTO myplayers values(2, 'Jonathan', 'Trott', 'CapeTown', 'SouthAfrica')");
   mysqli_query($con, "INSERT INTO myplayers values(3, 'Queen', 'Douglas', 'Texas', 'UnitedStates')");
   print("Record Inserted.....\n");

   //Retrieving the contents of the table
   $res = mysqli_query($con, "SELECT * FROM myplayers");

   print("Contents of the resultset...\n");
   //Contents of the resultset
   while ($row = mysqli_fetch_row($res)) {
      print("ID: ".$row[0]."\n");
      print("First_Name: ".$row[1]."\n");
      print("Last_Name: ".$row[2]."\n");
      print("Place_Of_Birth: ".$row[3]."\n");
      print("Country: ".$row[4]."\n");
   }

   //Closing the statement
   mysqli_free_result($res);

   //Closing the connection
   mysqli_close($con);
?>

Output

When the above code is executed, it will produce the following result -

Table Created.....
Record Inserted.....
Contents of the resultset...
ID: 1
First_Name: Kennedy
Last_Name: Nkpara
Place_Of_Birth: PortHarcourt
Country: Nigeria
ID: 2
First_Name: Jonathan
Last_Name: Trott
Place_Of_Birth: CapeTown
Country: SouthAfrica
ID: 3
First_Name: Queen
Last_Name: Douglas
Place_Of_Birth: Texas
Country: UnitedStates

If you try to get the contents of the result after freeing it as -

$con = mysqli_connect("localhost", "root", "password", "mydb");

mysqli_query($con, "CREATE TABLE myplayers(ID INT, First_Name VARCHAR(255), Last_Name VARCHAR(255), Place_Of_Birth VARCHAR(255), Country VARCHAR(255))");
print("Table Created.....\n");
mysqli_query($con, "INSERT INTO myplayers values(1, 'Kennedy', 'Nkpara', 'PortHarcourt', 'Nigeria')");
mysqli_query($con, "INSERT INTO myplayers values(2, 'Jonathan', 'Trott', 'CapeTown', 'SouthAfrica')");
mysqli_query($con, "INSERT INTO myplayers values(3, 'Queen', 'Douglas', 'Texas', 'UnitedStates')");
print("Record Inserted.....\n");

//Retrieving the contents of the table
$res = mysqli_query($con, "SELECT * FROM myplayers");

//Closing the statement
mysqli_free_result($res);

print("Contents of the resultset...\n");
//Contents of the resultset
while ($row = mysqli_fetch_row($res)) {
   print("ID: ".$row[0]."\n");
   print("First_Name: ".$row[1]."\n");
   print("Last_Name: ".$row[2]."\n");
   print("Place_Of_Birth: ".$row[3]."\n");
   print("Country: ".$row[4]."\n");
}

//Closing the connection
mysqli_close($con);

You are going to get an error as shown below -

Table Created.....
Record Inserted.....
Contents of the resultset...
PHP Warning:  mysqli_fetch_row(): Couldn't fetch mysqli_result in E:\PHPExamples\procedure_oriented.php on line 19

Warning: mysqli_fetch_row(): Couldn't fetch mysqli_result in E:\PHPExamples\procedure_oriented.php on line 19

Example2

In an object oriented style the syntax of this PHP function is $result->close(); Following is the example of this function in object oriented style $minus;

<?php
   //Creating a connection
   $con = new mysqli("localhost", "root", "password", "mydb");

   $con -> query("CREATE TABLE Test(Name VARCHAR(255), AGE INT)");
   $con -> query("insert into Test values('Kennedy', 27),('Paul', 30),('Justice', 28)");
   print("Table Created.....\n");

   $stmt = $con -> prepare( "SELECT * FROM Test WHERE Name in(?, ?)");
   $stmt -> bind_param("ss", $name1, $name2);
   $name1 = 'Kennedy';
   $name2 = 'Paul';

   //Executing the statement
   $stmt->execute();

   //Retrieving the result
   $result = $stmt->get_result();

   //Number of rows
   $count = $result->num_rows;
   print("Number of rows in the result: ".$count);

   //Closing the result
   $result->close();

   //Closing the statement
   $stmt->close();

   //Closing the connection
   $con->close();
?>

Output

When the above code is executed, it will produce the following result below -

Table Created.....
Number of rows in the result: 2


Alright guys! This is where we are going to be rounding up for this tutorial post. In our next tutorial, we are going to be discussing about the mysqli_num_fields() Function in PHP.

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