Insert multiple values to the same database column from HTML form

Question

I have created complex form, I'll try to provide simplified examples. There are ability to generate more fields by clicking + button.

For example in form are fields:

Certificate    Date Of Issue    Date of Expire   
[         ]    [           ]    [            ]   +

by clicking + button It add duplicate row (via javascript) so after clicking + button part of form looks like:

Certificate    Date Of Issue    Date of Expire   
[         ]    [           ]    [            ]

Certificate    Date Of Issue    Date of Expire  
[         ]    [           ]    [            ]   +

There are ability to click + button as many times as user needs.

In database table CV_Certificates I have columns CertificateId, CertDateofIssue, CertDateOfExpire

I'm using insert.php to insert values to database in following:

$Certificate = mysqli_real_escape_string($link, $_POST['Certificate']);             
$CertDateOfIssue = mysqli_real_escape_string($link, $_POST['CertDateOfIssue']);             
$CertDateOfExpire = mysqli_real_escape_string($link, $_POST['CertDateOfExpire']);

$sql = "INSERT INTO CV_Certificates (Certificate, CertDateOfIssue, CertDateOfExpire) VALUES ('$Certificate','$CertDateOfIssue','$CertDateOfExpire')

if(mysqli_query($link, $sql)){
    echo "Resume created successfully.";
} else{
    echo "ERROR: Could not able to execute $sql. " . mysqli_error($link);
}

It inserting values only from 1 row, but It should insert values from all added rows to multiple database table's rows.

---

HTML

<fieldset class="fieldset-borders">
<legend>5. Certificates</legend>

<ul class="Certificates" id="Certificates"> 
    <li>
        <ul class="column">         
            <li>
                <label for="Certificate">Certificate Name</label>
                <input id="Certificate" type="text" name="Certificate" class="field-style field-split25 align-left" placeholder="Certificate" />    
            </li>
        </ul>
    </li>   
    <li>
        <ul class="column">         
            <li>
                <label for="CertDateOfIssue">Date of Issue</label>
                <input id="CertDateOfIssue" type="date" name="CertDateOfIssue" class="field-style field-split25 align-left" placeholder="Date of Issue" />  
            </li>
        </ul>
    </li>
    <li>
        <ul class="column">         
            <li>
                <label for="CertDateOfExpire">Date of Expire</label>
                <input id="CertDateOfExpire" type="date" name="CertDateOfExpire" class="field-style field-split25 align-left" placeholder="Date of Expire" />   
            </li>
        </ul>
    </li>
</ul>   
<ul class="Certificates1"></ul>
<button type="button" class="add-row1">+</button> 

</fieldset>

---

Javascript

$(document).ready(function(){
   $( ".add-row1" ).click(function(){
      $( "ul.Certificates" ).first().clone().appendTo( ".Certificates1" ).append('<button class="remove">X</button>').find('input').val("");
   });
   $( "body" ).on('click', '.remove', function(){
    $(this).closest('.Certificates').remove();
  });
});

How could I achieve It? Also as I noticed, this is extremely simplified form, there are over 150 fields at all.

UPDATE

This is real part from my code which return an error: ERROR: Could not able to execute . And not inserting values to database at all now.

foreach($SeaService as $key=>$res) {

$sql2 = "INSERT INTO CV_SeaServices (
UserId
,NameOfVessel           
,TypeOfVessel           
,YearBuilt              
,Flag                   
,DWT                    
,TypeOfMEkW             
,SSRankApplied          
,SignOn                 
,SignOff                
,CompanyName            
) VALUES (
'$res',
'$NameOfVessel[$key]',      
'$TypeOfVessel[$key]',      
'$YearBuilt[$key]',             
'$Flag[$key]',              
'$DWT[$key]',               
'$TypeOfMEkW[$key]',        
'$SSRankApplied[$key]',         
'$SignOn[$key]',            
'$SignOff[$key]',           
'$CompanyName[$key]')";

};
if(mysqli_query($link, $sql2)){
    echo "Resume created successfully.";
} else{
    echo "ERROR: Could not able to execute $sql. " . mysqli_error($link);
}

Answer 1

Each input addition must have a new name, or the variable must be an array:

<input id="Certificate" type="date" name="Certificate[]" class="field-style field-split25 align-left" placeholder="Date of Expire" />`

<input id="CertDateOfIssue" type="date" name="CertDateOfIssue[]" class="field-style field-split25 align-left" placeholder="Date of Issue" /> `

<input id="CertDateOfIssue" type="date" name="CertDateOfIssue[]" class="field-style field-split25 align-left" placeholder="Date of Issue" />`

Now in your PHP

$certificate = mysqli_real_escape_string($link, $_POST['Certificate']);          
$certDateOfIssue = mysqli_real_escape_string($link, $_POST['CertDateOfIssue']);             
$certDateOfExpire = mysqli_real_escape_string($link, $_POST['CertDateOfExpire']);

foreach($certificate as $key=>$res) {
$sql = "INSERT INTO CV_Certificates (Certificate, CertDateOfIssue, CertDateOfExpire) VALUES ('$res','$certDateOfIssue[$key]','$certDateOfExpire[$key]')
}

UPDATE

foreach($SeaService as $key=>$res) {

$sql2 = "INSERT INTO CV_SeaServices (
UserId
,NameOfVessel           
,TypeOfVessel           
,YearBuilt              
,Flag                   
,DWT                    
,TypeOfMEkW             
,SSRankApplied          
,SignOn                 
,SignOff                
,CompanyName            
) VALUES (
'$res',
'$NameOfVessel[$key]',      
'$TypeOfVessel[$key]',      
'$YearBuilt[$key]',             
'$Flag[$key]',              
'$DWT[$key]',               
'$TypeOfMEkW[$key]',        
'$SSRankApplied[$key]',         
'$SignOn[$key]',            
'$SignOff[$key]',           
'$CompanyName[$key]')";
 if(mysqli_query($link, $sql2)){
    echo "Resume created successfully.";
} else{
    echo "ERROR: Could not able to execute $sql. " . mysqli_error($link);
}
}