PHP : Continue get me out - php

Question

Why my second if is never executed ? It seems like the continue sentence get me out of the foreach. I have tried the elseif without success.
foreach($columns as $i=>$column)
{
// Check if column exists
$sql = "SELECT '$column' FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_SCHEMA = '$database' AND TABLE_NAME = '$strTable'";
if(mysqli_real_query($link, $sql))
{
echo 'Column '.$column.' was created! <br>';
continue;
}
$sql = "alter table '$strTable' add column '$column' varchar (30)";
if(mysqli_real_query($link, $sql))
{
echo 'Column '.$column.' was created! <br>';
}
$cols .= $column.',';
}

Answer 1

You're not testing whether the query found any rows. mysqli_real_query() is successful as long as it didn't get an error, but that doesn't mean the query matched anything. You need to get the result of the query.
Also, you're just checking whether the table exists, not whether that column exists in the table.
continue skips the entire rest of the loop body. You should use else to execute the second block when the column isn't found.
Use mysqli_query() if you want to use the result. Otherwise, you need to call mysqli_use_result() and mysqli_store_result() first; see difference between mysqli_query and mysqli_real_query
foreach($columns as $column)
{
// Check if column exists
$sql = "SELECT 1 FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_SCHEMA = '$database' AND TABLE_NAME = '$strTable' AND COLUMN_NAME = '$column'";
$result = mysqli_query($link, $sql);
if(mysqli_num_rows($result) > 0)
{
echo 'Column '.$column.' already exists! <br>';
} else {
$sql = "alter table '$strTable' add column '$column' varchar (30)";
if(mysqli_real_query($link, $sql))
{
echo 'Column '.$column.' was created! <br>';
}
}
$cols .= $column.',';
}