Exporting my database to CSV with PHP

I created a code in php that performs a twitter search and saves the result (100 tweets) to a database. In this code, I also have the option to select all tweets from the database and export them to a csv file.

However, if the tweet has a line break it will look like this in csv: WhatdoIdotosavethistweetinjustonelineofcsv(deletelinebreak)

Thisismycodethatexportsthetweetstocsv:

//DatabaseConnection$host="xxxxxx";
$uname="xxxxx";
$pass="xxxxxx";
$database = "xxxxxx";   

$connection=mysql_connect($host,$uname,$pass); 

echo mysql_error();

//or die("Database Connection Failed");
$selectdb=mysql_select_db($database) or die("Database could not be selected");  
$result=mysql_select_db($database)
or die("database cannot be selected <br>");


// Fetch Record from Database

$output         = "";
$table          = "tabela_tweets_novo"; // Enter Your Table Name
$sql            = mysql_query("select tweet from $table");
$columns_total  = mysql_num_fields($sql);

// Get The Field Name

for ($i = 0; $i < $columns_total; $i++) {
    $heading    =   mysql_field_name($sql, $i);
    $output     .= '"'.$heading.'",';
}
$output .="\n";

// Get Records from the table

while ($row = mysql_fetch_array($sql)) {
for ($i = 0; $i < $columns_total; $i++) {

$acentua = utf8_decode($row["$i"]);
$output .='"'.$acentua.'",';
}
$output .="\n";
}

// Download the file

$filename =  "UUXPost.csv";
header('Content-type: application/csv');
header('Content-Disposition: attachment; filename='.$filename);

echo $output;
exit;