How To Create Crud Operation In Php and MySQL

How To Create Crud Operation In Php and MySQL.

What is CRUD

CRUD is an acronym for Create, Read, Update, and Delete. CRUD operations are basic data manipulation for database. We’ve already learned how to perform create (i.e. insert), read (i.e. select), update and delete operations in previous chapters. In this tutorial we’ll create a simple PHP application to perform all these operations on a MySQL database table at one place.

Well, let’s start by creating the table which we’ll use in all of our example.

Creating the Database Table

Execute the following SQL query to create a table named employees inside your MySQL database. We will use this table for all of our future operations.

 

CREATE TABLE employees(

id INT NOT NULL PRIMARY KEY AUTO_INCREMENT,

name VARCHAR(100) NOT NULL,

address VARCHAR(255) NOT NULL, salary INT(10) NOT NULL

);

Creating the Config File

After creating the table, we need create a PHP script in order to connect to the MySQL database server. Let’s create a file named “config.php” and put the following code inside it.

We’ll later include this config file in other pages using the PHP require_once() function.

<?php /* Database credentials. Assuming you are running MySQL server with default setting (user ‘root’ with no password) */ define(‘DB_SERVER’, ‘localhost’);

define(‘DB_USERNAME’, ‘root’);

define(‘DB_PASSWORD’, );

define(‘DB_NAME’, ‘demo’);

/* Attempt to connect to MySQL database */

$link = mysqli_connect(DB_SERVER, DB_USERNAME, DB_PASSWORD, DB_NAME);

// Check connection

if($link === false){ die(“ERROR: Could not connect. “ . mysqli_connect_error());

}

?>

Creating the Landing Page

First we will create a landing page for our CRUD application that contains a data grid showing the records from the employees database table. It also has action icons for each record displayed in the grid, that you may choose to view its details, update it, or delete it.

We’ll also add a create button on the top of the data grid that can be used for creating new records in the employees table. Create a file named “index.php” and put the following code in it:

 

<!DOCTYPE html>
<html lang=”en”>
<head>
<meta charset=”UTF-8″>
<title>Dashboard</title>
<link rel=”stylesheet” href=”https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.css”>
<script src=”https://ajax.googleapis.com/ajax/libs/jquery/1.12.4/jquery.min.js”></script>
<script src=”https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.js”></script>
<style type=”text/css”>
.wrapper{
width: 650px;
margin: 0 auto;
}
.page-header h2{
margin-top: 0;
}
table tr td:last-child a{
margin-right: 15px;
}
</style>
<script type=”text/javascript”>
$(document).ready(function(){
$(‘[data-toggle=”tooltip”]’).tooltip();
});
</script>
</head>
<body>
<div class=”wrapper”>
<div class=”container-fluid”>
<div class=”row”>
<div class=”col-md-12″>
<div class=”page-header clearfix”>
<h2 class=”pull-left”>Employees Details</h2>
<a href=”create.php” class=”btn btn-success pull-right”>Add New Employee</a>
</div>
<?php
// Include config file
require_once “config.php”;

// Attempt select query execution
$sql = “SELECT * FROM employees”;
if($result = mysqli_query($link, $sql)){
if(mysqli_num_rows($result) > 0){
echo “<table class=’table table-bordered table-striped’>”;
echo “<thead>”;
echo “<tr>”;
echo “<th>#</th>”;
echo “<th>Name</th>”;
echo “<th>Address</th>”;
echo “<th>Salary</th>”;
echo “<th>Action</th>”;
echo “</tr>”;
echo “</thead>”;
echo “<tbody>”;
while($row = mysqli_fetch_array($result)){
echo “<tr>”;
echo “<td>” . $row[‘id’] . “</td>”;
echo “<td>” . $row[‘name’] . “</td>”;
echo “<td>” . $row[‘address’] . “</td>”;
echo “<td>” . $row[‘salary’] . “</td>”;
echo “<td>”;
echo “<a href=’read.php?id=”. $row[‘id’] .”‘ title=’View Record’ data-toggle=’tooltip’><span class=’glyphicon glyphicon-eye-open’></span></a>”;
echo “<a href=’update.php?id=”. $row[‘id’] .”‘ title=’Update Record’ data-toggle=’tooltip’><span class=’glyphicon glyphicon-pencil’></span></a>”;
echo “<a href=’delete.php?id=”. $row[‘id’] .”‘ title=’Delete Record’ data-toggle=’tooltip’><span class=’glyphicon glyphicon-trash’></span></a>”;
echo “</td>”;
echo “</tr>”;
}
echo “</tbody>”;
echo “</table>”;
// Free result set
mysqli_free_result($result);
} else{
echo “<p class=’lead’><em>No records were found.</em></p>”;
}
} else{
echo “ERROR: Could not able to execute $sql. ” . mysqli_error($link);
}

// Close connection
mysqli_close($link);
?>
</div>
</div>
</div>
</div>
</body>
</html>

 

Creating the Create Page

In this section we’ll build the Create functionality of our CRUD application.

Let’s create a file named “create.php” and put the following code inside it. It will generate a web form that can be used to insert records in the employees table.

<?php
// Include config file
require_once “config.php”;

// Define variables and initialize with empty values
$name = $address = $salary = “”;
$name_err = $address_err = $salary_err = “”;

// Processing form data when form is submitted
if($_SERVER[“REQUEST_METHOD”] == “POST”){
// Validate name
$input_name = trim($_POST[“name”]);
if(empty($input_name)){
$name_err = “Please enter a name.”;
} elseif(!filter_var($input_name, FILTER_VALIDATE_REGEXP, array(“options”=>array(“regexp”=>”/^[a-zA-Z\s]+$/”)))){
$name_err = “Please enter a valid name.”;
} else{
$name = $input_name;
}

// Validate address
$input_address = trim($_POST[“address”]);
if(empty($input_address)){
$address_err = “Please enter an address.”;
} else{
$address = $input_address;
}

// Validate salary
$input_salary = trim($_POST[“salary”]);
if(empty($input_salary)){
$salary_err = “Please enter the salary amount.”;
} elseif(!ctype_digit($input_salary)){
$salary_err = “Please enter a positive integer value.”;
} else{
$salary = $input_salary;
}

// Check input errors before inserting in database
if(empty($name_err) && empty($address_err) && empty($salary_err)){
// Prepare an insert statement
$sql = “INSERT INTO employees (name, address, salary) VALUES (?, ?, ?)”;

if($stmt = mysqli_prepare($link, $sql)){
// Bind variables to the prepared statement as parameters
mysqli_stmt_bind_param($stmt, “sss”, $param_name, $param_address, $param_salary);

// Set parameters
$param_name = $name;
$param_address = $address;
$param_salary = $salary;

// Attempt to execute the prepared statement
if(mysqli_stmt_execute($stmt)){
// Records created successfully. Redirect to landing page
header(“location: index.php”);
exit();
} else{
echo “Something went wrong. Please try again later.”;
}
}

// Close statement
mysqli_stmt_close($stmt);
}

// Close connection
mysqli_close($link);
}
?>

<!DOCTYPE html>
<html lang=”en”>
<head>
<meta charset=”UTF-8″>
<title>Create Record</title>
<link rel=”stylesheet” href=”https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.css”>
<style type=”text/css”>
.wrapper{
width: 500px;
margin: 0 auto;
}
</style>
</head>
<body>
<div class=”wrapper”>
<div class=”container-fluid”>
<div class=”row”>
<div class=”col-md-12″>
<div class=”page-header”>
<h2>Create Record</h2>
</div>
<p>Please fill this form and submit to add employee record to the database.</p>
<form action=”<?php echo htmlspecialchars($_SERVER[“PHP_SELF”]); ?>” method=”post”>
<div class=”form-group <?php echo (!empty($name_err)) ? ‘has-error’ : ”; ?>”>
<label>Name</label>
<input type=”text” name=”name” class=”form-control” value=”<?php echo $name; ?>”>
<span class=”help-block”><?php echo $name_err;?></span>
</div>
<div class=”form-group <?php echo (!empty($address_err)) ? ‘has-error’ : ”; ?>”>
<label>Address</label>
<textarea name=”address” class=”form-control”><?php echo $address; ?></textarea>
<span class=”help-block”><?php echo $address_err;?></span>
</div>
<div class=”form-group <?php echo (!empty($salary_err)) ? ‘has-error’ : ”; ?>”>
<label>Salary</label>
<input type=”text” name=”salary” class=”form-control” value=”<?php echo $salary; ?>”>
<span class=”help-block”><?php echo $salary_err;?></span>
</div>
<input type=”submit” class=”btn btn-primary” value=”Submit”>
<a href=”index.php” class=”btn btn-default”>Cancel</a>
</form>
</div>
</div>
</div>
</div>
</body>
</html>

Creating the Read Page

Now it’s time to build the Read functionality of our CRUD application.

Let’s create a file named “read.php” and put the following code inside it. It will simply retrieve the records from the employees table based the id attribute of the employee.

<?php
// Check existence of id parameter before processing further
if(isset($_GET[“id”]) && !empty(trim($_GET[“id”]))){
// Include config file
require_once “config.php”;

// Prepare a select statement
$sql = “SELECT * FROM employees WHERE id = ?”;

if($stmt = mysqli_prepare($link, $sql)){
// Bind variables to the prepared statement as parameters
mysqli_stmt_bind_param($stmt, “i”, $param_id);

// Set parameters
$param_id = trim($_GET[“id”]);

// Attempt to execute the prepared statement
if(mysqli_stmt_execute($stmt)){
$result = mysqli_stmt_get_result($stmt);

if(mysqli_num_rows($result) == 1){
/* Fetch result row as an associative array. Since the result set contains only one row, we don’t need to use while loop */
$row = mysqli_fetch_array($result, MYSQLI_ASSOC);

// Retrieve individual field value
$name = $row[“name”];
$address = $row[“address”];
$salary = $row[“salary”];
} else{
// URL doesn’t contain valid id parameter. Redirect to error page
header(“location: error.php”);
exit();
}

} else{
echo “Oops! Something went wrong. Please try again later.”;
}
}

// Close statement
mysqli_stmt_close($stmt);

// Close connection
mysqli_close($link);
} else{
// URL doesn’t contain id parameter. Redirect to error page
header(“location: error.php”);
exit();
}
?>
<!DOCTYPE html>
<html lang=”en”>
<head>
<meta charset=”UTF-8″>
<title>View Record</title>
<link rel=”stylesheet” href=”https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.css”>
<style type=”text/css”>
.wrapper{
width: 500px;
margin: 0 auto;
}
</style>
</head>
<body>
<div class=”wrapper”>
<div class=”container-fluid”>
<div class=”row”>
<div class=”col-md-12″>
<div class=”page-header”>
<h1>View Record</h1>
</div>
<div class=”form-group”>
<label>Name</label>
<p class=”form-control-static”><?php echo $row[“name”]; ?></p>
</div>
<div class=”form-group”>
<label>Address</label>
<p class=”form-control-static”><?php echo $row[“address”]; ?></p>
</div>
<div class=”form-group”>
<label>Salary</label>
<p class=”form-control-static”><?php echo $row[“salary”]; ?></p>
</div>
<p><a href=”index.php” class=”btn btn-primary”>Back</a></p>
</div>
</div>
</div>
</div>
</body>
</html>

 

Creating the Update Page

Similarly, we can build the Update functionality of our CRUD application.

Let’s create a file named “update.php” and put the following code inside it. It will update the existing records in the employees table based the id attribute of the employee.

 

<?php
// Include config file
require_once “config.php”;

// Define variables and initialize with empty values
$name = $address = $salary = “”;
$name_err = $address_err = $salary_err = “”;

// Processing form data when form is submitted
if(isset($_POST[“id”]) && !empty($_POST[“id”])){
// Get hidden input value
$id = $_POST[“id”];

// Validate name
$input_name = trim($_POST[“name”]);
if(empty($input_name)){
$name_err = “Please enter a name.”;
} elseif(!filter_var($input_name, FILTER_VALIDATE_REGEXP, array(“options”=>array(“regexp”=>”/^[a-zA-Z\s]+$/”)))){
$name_err = “Please enter a valid name.”;
} else{
$name = $input_name;
}

// Validate address address
$input_address = trim($_POST[“address”]);
if(empty($input_address)){
$address_err = “Please enter an address.”;
} else{
$address = $input_address;
}

// Validate salary
$input_salary = trim($_POST[“salary”]);
if(empty($input_salary)){
$salary_err = “Please enter the salary amount.”;
} elseif(!ctype_digit($input_salary)){
$salary_err = “Please enter a positive integer value.”;
} else{
$salary = $input_salary;
}

// Check input errors before inserting in database
if(empty($name_err) && empty($address_err) && empty($salary_err)){
// Prepare an update statement
$sql = “UPDATE employees SET name=?, address=?, salary=? WHERE id=?”;

if($stmt = mysqli_prepare($link, $sql)){
// Bind variables to the prepared statement as parameters
mysqli_stmt_bind_param($stmt, “sssi”, $param_name, $param_address, $param_salary, $param_id);

// Set parameters
$param_name = $name;
$param_address = $address;
$param_salary = $salary;
$param_id = $id;

// Attempt to execute the prepared statement
if(mysqli_stmt_execute($stmt)){
// Records updated successfully. Redirect to landing page
header(“location: index.php”);
exit();
} else{
echo “Something went wrong. Please try again later.”;
}
}

// Close statement
mysqli_stmt_close($stmt);
}

// Close connection
mysqli_close($link);
} else{
// Check existence of id parameter before processing further
if(isset($_GET[“id”]) && !empty(trim($_GET[“id”]))){
// Get URL parameter
$id = trim($_GET[“id”]);

// Prepare a select statement
$sql = “SELECT * FROM employees WHERE id = ?”;
if($stmt = mysqli_prepare($link, $sql)){
// Bind variables to the prepared statement as parameters
mysqli_stmt_bind_param($stmt, “i”, $param_id);

// Set parameters
$param_id = $id;

// Attempt to execute the prepared statement
if(mysqli_stmt_execute($stmt)){
$result = mysqli_stmt_get_result($stmt);

if(mysqli_num_rows($result) == 1){
/* Fetch result row as an associative array. Since the result set contains only one row, we don’t need to use while loop */
$row = mysqli_fetch_array($result, MYSQLI_ASSOC);

// Retrieve individual field value
$name = $row[“name”];
$address = $row[“address”];
$salary = $row[“salary”];
} else{
// URL doesn’t contain valid id. Redirect to error page
header(“location: error.php”);
exit();
}

} else{
echo “Oops! Something went wrong. Please try again later.”;
}
}

// Close statement
mysqli_stmt_close($stmt);

// Close connection
mysqli_close($link);
} else{
// URL doesn’t contain id parameter. Redirect to error page
header(“location: error.php”);
exit();
}
}
?>

<!DOCTYPE html>
<html lang=”en”>
<head>
<meta charset=”UTF-8″>
<title>Update Record</title>
<link rel=”stylesheet” href=”https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.css”>
<style type=”text/css”>
.wrapper{
width: 500px;
margin: 0 auto;
}
</style>
</head>
<body>
<div class=”wrapper”>
<div class=”container-fluid”>
<div class=”row”>
<div class=”col-md-12″>
<div class=”page-header”>
<h2>Update Record</h2>
</div>
<p>Please edit the input values and submit to update the record.</p>
<form action=”<?php echo htmlspecialchars(basename($_SERVER[‘REQUEST_URI’])); ?>” method=”post”>
<div class=”form-group <?php echo (!empty($name_err)) ? ‘has-error’ : ”; ?>”>
<label>Name</label>
<input type=”text” name=”name” class=”form-control” value=”<?php echo $name; ?>”>
<span class=”help-block”><?php echo $name_err;?></span>
</div>
<div class=”form-group <?php echo (!empty($address_err)) ? ‘has-error’ : ”; ?>”>
<label>Address</label>
<textarea name=”address” class=”form-control”><?php echo $address; ?></textarea>
<span class=”help-block”><?php echo $address_err;?></span>
</div>
<div class=”form-group <?php echo (!empty($salary_err)) ? ‘has-error’ : ”; ?>”>
<label>Salary</label>
<input type=”text” name=”salary” class=”form-control” value=”<?php echo $salary; ?>”>
<span class=”help-block”><?php echo $salary_err;?></span>
</div>
<input type=”hidden” name=”id” value=”<?php echo $id; ?>”/>
<input type=”submit” class=”btn btn-primary” value=”Submit”>
<a href=”index.php” class=”btn btn-default”>Cancel</a>
</form>
</div>
</div>
</div>
</div>
</body>
</html>

Creating the Delete Page

Finally, we will build the Delete functionality of our CRUD application.

Let’s create a file named “delete.php” and put the following code inside it. It will delete the existing records from the employees table based the id attribute of the employee.

<?php
// Process delete operation after confirmation
if(isset($_POST[“id”]) && !empty($_POST[“id”])){
// Include config file
require_once “config.php”;

// Prepare a delete statement
$sql = “DELETE FROM employees WHERE id = ?”;

if($stmt = mysqli_prepare($link, $sql)){
// Bind variables to the prepared statement as parameters
mysqli_stmt_bind_param($stmt, “i”, $param_id);

// Set parameters
$param_id = trim($_POST[“id”]);

// Attempt to execute the prepared statement
if(mysqli_stmt_execute($stmt)){
// Records deleted successfully. Redirect to landing page
header(“location: index.php”);
exit();
} else{
echo “Oops! Something went wrong. Please try again later.”;
}
}

// Close statement
mysqli_stmt_close($stmt);

// Close connection
mysqli_close($link);
} else{
// Check existence of id parameter
if(empty(trim($_GET[“id”]))){
// URL doesn’t contain id parameter. Redirect to error page
header(“location: error.php”);
exit();
}
}
?>
<!DOCTYPE html>
<html lang=”en”>
<head>
<meta charset=”UTF-8″>
<title>View Record</title>
<link rel=”stylesheet” href=”https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.css”>
<style type=”text/css”>
.wrapper{
width: 500px;
margin: 0 auto;
}
</style>
</head>
<body>
<div class=”wrapper”>
<div class=”container-fluid”>
<div class=”row”>
<div class=”col-md-12″>
<div class=”page-header”>
<h1>Delete Record</h1>
</div>
<form action=”<?php echo htmlspecialchars($_SERVER[“PHP_SELF”]); ?>” method=”post”>
<div class=”alert alert-danger fade in”>
<input type=”hidden” name=”id” value=”<?php echo trim($_GET[“id”]); ?>”/>
<p>Are you sure you want to delete this record?</p><br>
<p>
<input type=”submit” value=”Yes” class=”btn btn-danger”>
<a href=”index.php” class=”btn btn-default”>No</a>
</p>
</div>
</form>
</div>
</div>
</div>
</div>
</body>
</html>

Creating the Error Page

At the end, let’s create one more file “error.php”. This page will be displayed if request is invalid i.e. if id parameter is missing from the URL query string or it is not valid.

<!DOCTYPE html>
<html lang=”en”>
<head>
<meta charset=”UTF-8″>
<title>Error</title>
<link rel=”stylesheet” href=”https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.css”>
<style type=”text/css”>
.wrapper{
width: 750px;
margin: 0 auto;
}
</style>
</head>
<body>
<div class=”wrapper”>
<div class=”container-fluid”>
<div class=”row”>
<div class=”col-md-12″>
<div class=”page-header”>
<h1>Invalid Request</h1>
</div>
<div class=”alert alert-danger fade in”>
<p>Sorry, you’ve made an invalid request. Please <a href=”index.php” class=”alert-link”>go back</a> and try again.</p>
</div>
</div>
</div>
</div>
</div>
</body>
</html>

After a long journey finally we’ve finished our CRUD application with PHP and MySQL. We recommend you to check out PHP & MySQL database tutorial section from the beginning, if you haven’t already covered, for a better understanding of each and every part of this tutorial.

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