If you have a form that allows you to submit multiple responsibilities simultaneously then I would use PDO. Remember PDO is your friend, and always sanitize your inputs before inserting them. Here is them most basic version, You probably want to replace the inputs with dropdowns or texteareas.
table
responsibilityID|PositionID|responsibility
The responsibilityID should be PK and auto-increment
html
<form>
<div>
<h1>job</h1>
<label>PositionID</label><input name='jobs[][positionID]' />
<label>responsability</label><input name='jobs[][responsibility]' />
</div>
<div>
<h1>job</h1>
<label>PositionID</label><input name='jobs[][positionID]' />
<label>responsability</label><input name='jobs[][responsibility]' />
</div>
<div>
<h1>job</h1>
<label>PositionID</label><input name='jobs[][positionID]' />
<label>responsability</label><input name='jobs[][responsibility]' />
</div>
<div>
<h1>job</h1>
<label>PositionID</label><input name='jobs[][positionID]' />
<label>responsability</label><input name='jobs[][responsibility]' />
</div>
<input type='submit' />
</form>
Basic
Create an insert statement then loop through your jobs binding each value to the statement and executing them.
$insert_sql = "INSERT INTO responsibilities (`PositionID`, `responsibility`) VALUES (:PositionID, :responsibility);";
$stmt = PDO::Prepare($insert_sql)
foreach ($jobs as $job){
//add some input testing before you execute to make sure you are not inserting bad values
$stmt->bindValue(":positionID", $job['positionID'], PDO::PARAM_INT);
$stmt->bindValue(":responsibility", $job['responsibility'], PDO::PARAM_STR);
$stmt->execute();
}
The :fieldname in the query tells PDO what needs to be replaced with the bind functions, then the bindValue/bindParam functions tells what to insert where into the query and properly escapes the value so you can insert it. Older sql functions allowed for unescaped or improperly escaped values and you got the little bobby tables problem. PDO protects you from some of the worst injection attacks, but you should probably make sure that positionID points to a real position or that responsibility doesn't have weird java-script exploit code in it.
Fancy
Create an insert statement, bind params, then foreach loop through your responsibilities, checking/sanitizing the input (never trust form data) then executing the statement. Every time you loop the bound parameter will point at the new job.
$insert_sql = "INSERT INTO responsibilities (`PositionID`, `responsibility`) VALUES (:PositionID, :responsibility);";
$job = array('positionID'=>NULL, 'responsibility'->NULL);
$stmt = PDO::Prepare($insert_sql)
$stmt->bindParam(":positionID", $job['positionID'], PDO::PARAM_INT);
$stmt->bindParam(":responsibility", $job['responsibility'], PDO::PARAM_STR);
foreach ($jobs as $job){
//add some input testing before you execute to make sure you are not inserting bad values
$stmt->execute();
}
