Re: Relational database
| From: | Andrey Hristov | Date: | Thu, 21 Mar 2002 13:41:03 +0000 |
| Subject: | Re: Relational database | ||
| References: | 1 | Groups: | php.db |
| Request: | Send a blank email to php-db+get-17801@lists.php.net to get a copy of this message | ||
The info is not full but I'll try to help. Lets say the name of the field in the two tables is
common_field.
Then we do
SELECT all_that_is_needed FROM table1,table2 WHERE table1.common_field=table2.common_field;
And an optimized variant:
SELECT all_that_is_needed FROM table1 LEFT JOIN table2 USING(common_field);
If in the two tables we have two columns with equal data but with different names then we do:
SELECT all_that_is_needed FROM table1 LEFT JOIN table2 ON
table1.common_field_name_table1=table2.common_field_name_table2;
So
SELECT all_that_is_needed FROM table1 LEFT JOIN table2 USING(common_field);
is equal to:
SELECT all_that_is_needed FROM table1 LEFT JOIN table2 ON table1.common_field=table2.common_field;
Hope that is clear.
Best regards,
Andrey
----- Original Message -----
From: "Ron" <allenr@fwd.areur.army.mil>
To: <php-db@lists.php.net>
Sent: Thursday, March 21, 2002 3:32 PM
Subject: [PHP-DB] Relational database
> I am trying to get fields from 2 different tables that have the same field
> name to pull the records from one table
> For example
> mysql_connect($DBhost,$DBuser,$DBpass) or die("Unable toconnect to
> database");
> @mysql_select_db("$DBName") or die("Unable to select database $DBName");
> $sqlquery1 = mysql_query("SELECT Description, Impact, Isolation" .
> "FROM ccsd, log WHERE ccsd=log.logccsd");
>
> while ($query = mysql_fetch_array($sqlquery1)) {
> $CCSD = $query["CCSD"];
> $Description = $query["Description"];
> $Impact = $query["Impact"];
> $Isolation = $query["Isolation"];
> }
> This code is not working.....help please.........yes I am a newbie!
>
>
>
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