Parse error: syntax error, unexpected 'UNION' (T

I'm trying to display a table with all records including NULL values and I've tried everything I can think of including the UNION operator. This is my code:

<?php

include "dbconfig.php";

$con = mysqli_connect($host, $username, $password, $dbname)
or die ("<br>Cannot connect to DB\n");

$sql = ("SELECT * FROM TECH3740.EMPLOYEE") UNION ("SELECT * FROM TECH3740.EMPLOYEE WHERE 
salary IS NULL");
$result = mysqli_query($con, $sql);

?>

<!DOCTYPE HTML>
<HTML>
<HEAD>

</HEAD>

<BODY>

<?php

if(mysqli_num_rows($result) > 0) {
?>

<TABLE border ="1" cellspacing = "0" cellpadding ="5">
<tr>
    <TH>ID</TH>
    <TH>Login</TH>
    <TH>Password</TH>
    <TH>Name</TH>
    <TH>Role</TH>
    <TH>Gender</TH>
    <TH>Salary</TH>
    <TH>Address</TH>

</tr>

<?php
$i = 0;
while($row = mysqli_fetch_array($result)) {
    ?>

    <tr>
        <TD><?php echo $row["employee_id"]; ?></TD>
        <TD><?php echo $row["login"]; ?></TD>
        <TD><?php echo $row["password"]; ?></TD>
        <TD><?php echo $row["name"]; ?></TD>
        <TD><?php echo $row["role"]; ?></TD>
        <TD><?php echo $row["gender"]; ?></TD>
        <TD><?php echo $row["salary"]; ?></TD>
        <TD><?php echo $row["Address"]; ?></TD>
    </tr>
<?php
    $i  ;
}
?>

</TABLE>

<?php
}
else{
    echo "No result found";
}
?>

</BODY>
</HTML>

It's throwing a Parse error: syntax error, unexpected 'UNION' (T_STRING) on line 8. I'm not sure what else to try. Any advice?

CodePudding user response：

You have the quotes in the wrong place, they should be around the entire SQL query. UNION is SQL syntax, not PHP.

$sql = "SELECT * 
        FROM TECH3740.EMPLOYEE 
        UNION 
        SELECT * 
        FROM TECH3740.EMPLOYEE 
        WHERE salary IS NULL";

CodePudding user response：

You don't really need to use a UNION just quote your query in this way

$sql = "SELECT * FROM TECH3740.EMPLOYEE";

This will pick up ALL the rows including the NULLs