PHP mysqli_warning_count() Function

---

---

Definition and Usage

if your last MySQLi function call executes MySQL query and if it generates any errors. The mysqli_warning_count() function counts the number of errors generated by the last executed query and, returns the result.

Syntax

mysqli_warning_count($con)

Parameters

Return Values

PHP mysqli_warning_count() function returns an integer value representing the number of warnings generated during the execution of last query. If there are no warnings during the last execution this function returns 0

PHP Version

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

Assume we have created a table named Emp as follows −

CREATE TABLE EMP(
    ID TINYINT,
    First_Name VARCHAR(50) Not NULL, 
    Last_Name VARCHAR(10) Not NULL, 
    Date_Of_Birth date, 
    Salary Int(255)
);

Example

Following example demonstrates the usage of the mysqli_warning_count() function (in procedural style) −

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

   //Inserting a record into the employee table
   $sql = "INSERT IGNORE into emp values(1, 'Sanjay', NULL, DATE('1981-12-05'), 2566)";
   mysqli_query($con, $sql);
   //Number of Warnings
   $count = mysqli_warning_count($con);
   print("Number of Warnings: ".$count ."\n");

   $sql = "INSERT IGNORE into emp values (15, 'Swetha', 'Yellapragada', DATE('1990-11-25'), 9986), (15, NULL, 'Prayaga', DATE('1990-11-25'), 9986)";
   mysqli_query($con, $sql);
   //Number of Warnings
   $count = mysqli_warning_count($con);
   print("Number of Warnings: ".$count);

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

This will produce following result −

Number of Warnings: 1
Number of Warnings: 2

Example

In object oriented style the syntax of this function is $con -> warning_count, Where, $con is the connection object −

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

   //Inserting a record into the employee table
   $con -> query("INSERT IGNORE into emp values(1, 'Sanjay', NULL, DATE('1981-12-05'), 2566)");
   //Number of Warnings
   $count1 = $con->warning_count;
   print("Number of Warnings: ".$count1."\n");

   //Inserting a record into the employee table
   $con -> query("INSERT IGNORE into emp values(15, 'Swetha', 'Yellapragada', DATE('1990-11-25'), 9986), (15, NULL, 'Prayaga', DATE('1990-11-25'), 9986)");
   //Number of Warnings
   $count2 = $con->warning_count;
   print("Number of Warnings: ".$count2);

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

This will produce following result −

Number of Warnings: 0
Number of Warnings: 2

Example

Following is another example of the function mysqli_warning_count() −

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

   //Warning count for proper query
   mysqli_query($con, "SELECT * FROM EMP");
   print("No.Of Warnings (proper query): ".mysqli_warning_count($con)."\n");

   //Query to DROP an unknown table
   mysqli_query($con, "drop table if exists WrongTable");
   print("No.Of Warnings: ".mysqli_warning_count($con)."\n");

   //Warnings of before last statement
   mysqli_query($con, "INSERT IGNORE into emp values(107, 'Sunitha', NULL, DATE('1981-12-05'), 2566)");
   mysqli_query($con, "INSERT IGNORE into emp values(7, 'Mohit', 'Sharma', DATE('1981-12-05'), 2566)");
   print("No.Of Warnings (if before last query contains errors): ".mysqli_warning_count($con)."\n");

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

This will produce following result −

Insert ID (select query): 0
Insert ID: (multiple inserts) 6
Insert ID (update query): 0
Insert ID: (table with out auto incremented key) 0

Example

<?php
   $servername = "localhost";
   $username = "root";
   $password = "password";
   $dbname = "mydb";
   $conn = new mysqli($servername, $username, $password, $dbname);

   if (!$conn->real_connect($servername, $username, $password, $dbname)) {
      die('Connect Error (' . mysqli_connect_errno() . ') '. mysqli_connect_error());
   }
   print("Database connected" ."\n");
   mysqli_query($conn, "CREATE TABLE sample (ID INT, Name VARCHAR(20))");
   $query = "INSERT IGNORE INTO sample (id,name) VALUES(
      1,'Rajesh Ramayan Kootrapally')";

   mysqli_query($conn, $query);
   $warnings = mysqli_warning_count($conn);
   print("No.Of warnings in the query:".$warnings."\n");

   if ($warnings) {
      if ($result = mysqli_query($conn, "SHOW WARNINGS")) {
         $row = mysqli_fetch_row($result);
         printf("%s (%d): %s\n", $row[0], $row[1], $row[2]);
         mysqli_free_result($result);
      }
   }

   mysqli_close($conn);
?>

This will produce following result −

Database connected
No.Of warnings in the query:1
Warning (1265): Data truncated for column 'Name' at row 1