Question

I need to SELECT from more than one table that has a lot of fields. Do I have to manually fabricate the query like this:

table1.field1 AS table1_field1, table1.field2 AS table1_field2, ..., table2.field1 AS table2_field1, ...

Or is there any workaround for this in MySQL or PHP that will automatically take care of all these when there are identical field names in the tables?

In PHP, I tried:

$results = $conn -> query("SELECT table1.*, table2.* FROM table1, table2 WHERE 1"); // $conn is a mysqli object
$results = $results -> fetch_array();

But if there is a field named ‘title’ in both of the 2 tables, $results[‘title’] would just contain the value of the record from the 2nd table.

I know there are numeric indexes that you can use to access the value but:

1. It’s unreadable.
2. You have to update the code accordingly every time the table structure such as the order of the fields changes.

Any idea?

Answer 1

Yes, there are workarounds.
mysql and mysqli extensions, as well as certain pdo drivers, have functions to let you get at column meta data. Heres a pdo sample

$stmt->execute();
$qualifiedColumnNames = array();
for ($i = 0; $i < $stmt->columnCount(); $i++) {
    $columnMeta = $stmt->getColumnMeta($i);
    $qualifiedColumnNames[] = "$columnMeta[table].$columnMeta[name]";
}

print_r(array_combine($qualifiedColumnNames, $stmt->fetch(PDO::FETCH_NUM)));

So you can use table1.* and be able to differentiate conflicting column names.

Also, another trick that works because the column order in the result set is deterministic.

select 'table1' table_sep1
       table1.*
       'table1' table_sep2
       table2.*

I’ll leave the code up to you, but you can fetch a row as an array, and loop through the array keys. Since they will be in order, you can assume each column that follows a table separator column belongs to the table specified by the separator, until you come across the next sep.