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"===" compares on equal text and type. "01234" == 1234 are equally
compared as string values equals true. But "01234" === 1234 compared as
a string value is true, but "01234" is a string and 1234 is an integer
will return false with "===" <br>
<br>
<br>
<a class="moz-txt-link-abbreviated" href="mailto:ciapug-request@cialug.org">ciapug-request@cialug.org</a> wrote:
<blockquote cite="mid20070404170004.158048768@www.cialug.org"
type="cite">
<pre wrap="">Send ciapug mailing list submissions to
<a class="moz-txt-link-abbreviated" href="mailto:ciapug@cialug.org">ciapug@cialug.org</a>
To subscribe or unsubscribe via the World Wide Web, visit
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or, via email, send a message with subject or body 'help' to
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You can reach the person managing the list at
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When replying, please edit your Subject line so it is more specific
than "Re: Contents of ciapug digest..."
Today's Topics:
1. MySQL conference in Omaha yesterday (<a class="moz-txt-link-abbreviated" href="mailto:carl-olsen@mchsi.com">carl-olsen@mchsi.com</a>)
2. Re: MySQL conference in Omaha yesterday (<a class="moz-txt-link-abbreviated" href="mailto:carl-olsen@mchsi.com">carl-olsen@mchsi.com</a>)
3. yeah, weakly typed languages (Barry Von Ahsen)
4. Re: yeah, weakly typed languages (<a class="moz-txt-link-abbreviated" href="mailto:carl-olsen@mchsi.com">carl-olsen@mchsi.com</a>)
5. Re: yeah, weakly typed languages (<a class="moz-txt-link-abbreviated" href="mailto:carl-olsen@mchsi.com">carl-olsen@mchsi.com</a>)
6. Re: yeah, weakly typed languages (<a class="moz-txt-link-abbreviated" href="mailto:carl-olsen@mchsi.com">carl-olsen@mchsi.com</a>)
7. Re: yeah, weakly typed languages (Dave J. Hala Jr.)
8. Re: yeah, weakly typed languages (<a class="moz-txt-link-abbreviated" href="mailto:carl-olsen@mchsi.com">carl-olsen@mchsi.com</a>)
9. Re: yeah, weakly typed languages (<a class="moz-txt-link-abbreviated" href="mailto:carl-olsen@mchsi.com">carl-olsen@mchsi.com</a>)
----------------------------------------------------------------------
Message: 1
Date: Wed, 04 Apr 2007 13:35:39 +0000
From: <a class="moz-txt-link-abbreviated" href="mailto:carl-olsen@mchsi.com">carl-olsen@mchsi.com</a>
Subject: [ciapug] MySQL conference in Omaha yesterday
To: <a class="moz-txt-link-abbreviated" href="mailto:ciapug@cialug.org">ciapug@cialug.org</a>
Message-ID:
<a class="moz-txt-link-rfc2396E" href="mailto:040420071335.12652.4613A9AB0002B9430000316C219791332903010CD2079C080C03BF020A9C0401D3049D0E0C@mchsi.com"><040420071335.12652.4613A9AB0002B9430000316C219791332903010CD2079C080C03BF020A9C0401D3049D0E0C@mchsi.com></a>
Some of the things I learned yesterday:
1. Never use pconnect (the persistent connection function is going to be removed from PHP 6).
2. Always use prepared statements (requires mysqli).
3. Never use mysqli unless you are using prepared statements or other functions that do not exist in mysql (mysql runs faster).
4. Rarely use stored procedures because they are per thread (unlike other databases). They are not compiled and stored like they are in other databases. I think they are compiled at the start of a thread, but not permanently. I'm not sure I caught all the details on this, but its possible that stored procedure functionality will be improved in future releases of MySQL. Right now, their functionality is fairly crude.
5. Never use a function on a condition (filter) in a “WHERE” clause because indexing will be ignored. The function has to run on every row, so it's just a sequential operation because of the function being used on the column.
6. Triggers are okay because they don’t run as often as stored procedures and have a lighter footprint.
7. EXPLAIN will show you how MySQL actually executes an SQL query (which is often different than the way it is written).
8. Two additional table types (in addition to InnoDB, MyISAM and others), are MEMORY and ARCHIVE. I think the one that will likely get full text indexing as well as support for foreign keys was called "Falcon" or something like that (I never heard of it before). MyISAM is going to run faster than InnoDB in most cases because it is not as complicated as InnoDB.
9. To get a query to show vertically from the command line instead of in a table use “/G” switch at the end of the query.
--
Carl Olsen, MCSE
Web Developer
Marketing and Communications
Drake University
2507 University Avenue
115 Old Main
Des Moines, Iowa 50311-4505
Phone: 515-271-2986
Fax: 515-271-3798
<a class="moz-txt-link-abbreviated" href="mailto:Carl.Olsen@drake.edu">Carl.Olsen@drake.edu</a>
<a class="moz-txt-link-abbreviated" href="http://www.drake.edu">www.drake.edu</a>
------------------------------
Message: 2
Date: Wed, 04 Apr 2007 13:57:17 +0000
From: <a class="moz-txt-link-abbreviated" href="mailto:carl-olsen@mchsi.com">carl-olsen@mchsi.com</a>
Subject: Re: [ciapug] MySQL conference in Omaha yesterday
To: <a class="moz-txt-link-abbreviated" href="mailto:ciapug@cialug.org">ciapug@cialug.org</a>, <a class="moz-txt-link-abbreviated" href="mailto:ciapug@cialug.org">ciapug@cialug.org</a>
Cc: <a class="moz-txt-link-abbreviated" href="mailto:carl-olsen@mchsi.com">carl-olsen@mchsi.com</a>
Message-ID:
<a class="moz-txt-link-rfc2396E" href="mailto:040420071357.2782.4613AEBD00011AB600000ADE219791332903010CD2079C080C03BF020A9C0401D3049D0E0C@mchsi.com"><040420071357.2782.4613AEBD00011AB600000ADE219791332903010CD2079C080C03BF020A9C0401D3049D0E0C@mchsi.com></a>
Another interesting thing was query caching. If you use the MySQL function for calculating a date inside a query, it will not cache the query - but always executes the query. Using a PHP function to calculate the date creates a static query string and MySQL will cache the results and return the result from cache instead of re-running the query every time it is called.
-------------- Original message ----------------------
From: <a class="moz-txt-link-abbreviated" href="mailto:carl-olsen@mchsi.com">carl-olsen@mchsi.com</a>
</pre>
<blockquote type="cite">
<pre wrap="">Some of the things I learned yesterday:
1. Never use pconnect (the persistent connection function is going to be removed
from PHP 6).
2. Always use prepared statements (requires mysqli).
3. Never use mysqli unless you are using prepared statements or other functions
that do not exist in mysql (mysql runs faster).
4. Rarely use stored procedures because they are per thread (unlike other
databases). They are not compiled and stored like they are in other databases.
I think they are compiled at the start of a thread, but not permanently. I'm
not sure I caught all the details on this, but its possible that stored
procedure functionality will be improved in future releases of MySQL. Right
now, their functionality is fairly crude.
5. Never use a function on a condition (filter) in a “WHERE” clause because
indexing will be ignored. The function has to run on every row, so it's just a
sequential operation because of the function being used on the column.
6. Triggers are okay because they don’t run as often as stored procedures and
have a lighter footprint.
7. EXPLAIN will show you how MySQL actually executes an SQL query (which is
often different than the way it is written).
8. Two additional table types (in addition to InnoDB, MyISAM and others), are
MEMORY and ARCHIVE. I think the one that will likely get full text indexing as
well as support for foreign keys was called "Falcon" or something like that (I
never heard of it before). MyISAM is going to run faster than InnoDB in most
cases because it is not as complicated as InnoDB.
9. To get a query to show vertically from the command line instead of in a table
use “/G” switch at the end of the query.
--
Carl Olsen, MCSE
Web Developer
Marketing and Communications
Drake University
2507 University Avenue
115 Old Main
Des Moines, Iowa 50311-4505
Phone: 515-271-2986
Fax: 515-271-3798
<a class="moz-txt-link-abbreviated" href="mailto:Carl.Olsen@drake.edu">Carl.Olsen@drake.edu</a>
<a class="moz-txt-link-abbreviated" href="http://www.drake.edu">www.drake.edu</a>
_______________________________________________
ciapug mailing list
<a class="moz-txt-link-abbreviated" href="mailto:ciapug@cialug.org">ciapug@cialug.org</a>
<a class="moz-txt-link-freetext" href="http://cialug.org/mailman/listinfo/ciapug">http://cialug.org/mailman/listinfo/ciapug</a>
</pre>
</blockquote>
<pre wrap=""><!---->
------------------------------
Message: 3
Date: Wed, 04 Apr 2007 11:15:33 -0500
From: Barry Von Ahsen <a class="moz-txt-link-rfc2396E" href="mailto:barry@vonahsen.com"><barry@vonahsen.com></a>
Subject: [ciapug] yeah, weakly typed languages
To: <a class="moz-txt-link-abbreviated" href="mailto:ciapug@cialug.org">ciapug@cialug.org</a>
Message-ID: <a class="moz-txt-link-rfc2396E" href="mailto:4613CF25.1070404@vonahsen.com"><4613CF25.1070404@vonahsen.com></a>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
echo "phpversion: ".phpversion()."<br>";
$a = "01234";
$b = "1234";
echo "a:". $a."<br>";
echo "b:". $b."<br>";
if($a == $b) { echo "a==b"; } else { echo "a!=b"; } echo "<br>";
if($a === $b) { echo "a===b"; } else { echo "a!==b"; } echo "<br>";
echo "gettype(a):". gettype($a)."<br>";
echo "gettype(b):". gettype($b)."<br>";
$c = "0foo";
$d = "foo";
echo "c:". $c."<br>";
echo "d:". $d."<br>";
if($c == $d) { echo "c==d"; } else { echo "c!=d"; } echo "<br>";
if($c === $d) { echo "c===d"; } else { echo "c!==d"; } echo "<br>";
output:
phpversion: 4.4.0
a:01234
b:1234
a==b
a!==b
gettype(a):string
gettype(b):string
c:0foo
d:foo
c!=d
c!==d
I totally understand why "01234"==1234, but not why "01234"=="1234". If
I'm doing string=>string, no conversion should happen. However, if it
does, why doesn't "0foo"=>0 and "foo"=>0 so "0foo"=="foo" also?!?
-barry
------------------------------
Message: 4
Date: Wed, 04 Apr 2007 16:36:29 +0000
From: <a class="moz-txt-link-abbreviated" href="mailto:carl-olsen@mchsi.com">carl-olsen@mchsi.com</a>
Subject: Re: [ciapug] yeah, weakly typed languages
To: <a class="moz-txt-link-abbreviated" href="mailto:barry@vonahsen.com">barry@vonahsen.com</a>, <a class="moz-txt-link-abbreviated" href="mailto:ciapug@cialug.org">ciapug@cialug.org</a>, <a class="moz-txt-link-abbreviated" href="mailto:ciapug@cialug.org">ciapug@cialug.org</a>
Cc: Barry Von Ahsen <a class="moz-txt-link-rfc2396E" href="mailto:barry@vonahsen.com"><barry@vonahsen.com></a>
Message-ID:
<a class="moz-txt-link-rfc2396E" href="mailto:040420071636.8196.4613D40D0003811900002004219791332903010CD2079C080C03BF020A9C0401D3049D0E0C@mchsi.com"><040420071636.8196.4613D40D0003811900002004219791332903010CD2079C080C03BF020A9C0401D3049D0E0C@mchsi.com></a>
I have never used this, but isn't "===" a function that might solve this?
I think "==" is equality, and "===" is absolute equality.
Carl
-------------- Original message ----------------------
From: Barry Von Ahsen <a class="moz-txt-link-rfc2396E" href="mailto:barry@vonahsen.com"><barry@vonahsen.com></a>
</pre>
<blockquote type="cite">
<pre wrap=""> echo "phpversion: ".phpversion()."<br>";
$a = "01234";
$b = "1234";
echo "a:". $a."<br>";
echo "b:". $b."<br>";
if($a == $b) { echo "a==b"; } else { echo "a!=b"; } echo "<br>";
if($a === $b) { echo "a===b"; } else { echo "a!==b"; } echo "<br>";
echo "gettype(a):". gettype($a)."<br>";
echo "gettype(b):". gettype($b)."<br>";
$c = "0foo";
$d = "foo";
echo "c:". $c."<br>";
echo "d:". $d."<br>";
if($c == $d) { echo "c==d"; } else { echo "c!=d"; } echo "<br>";
if($c === $d) { echo "c===d"; } else { echo "c!==d"; } echo "<br>";
output:
phpversion: 4.4.0
a:01234
b:1234
a==b
a!==b
gettype(a):string
gettype(b):string
c:0foo
d:foo
c!=d
c!==d
I totally understand why "01234"==1234, but not why "01234"=="1234". If
I'm doing string=>string, no conversion should happen. However, if it
does, why doesn't "0foo"=>0 and "foo"=>0 so "0foo"=="foo" also?!?
-barry
_______________________________________________
ciapug mailing list
<a class="moz-txt-link-abbreviated" href="mailto:ciapug@cialug.org">ciapug@cialug.org</a>
<a class="moz-txt-link-freetext" href="http://cialug.org/mailman/listinfo/ciapug">http://cialug.org/mailman/listinfo/ciapug</a>
</pre>
</blockquote>
<pre wrap=""><!---->
------------------------------
Message: 5
Date: Wed, 04 Apr 2007 16:42:05 +0000
From: <a class="moz-txt-link-abbreviated" href="mailto:carl-olsen@mchsi.com">carl-olsen@mchsi.com</a>
Subject: Re: [ciapug] yeah, weakly typed languages
To: <a class="moz-txt-link-abbreviated" href="mailto:barry@vonahsen.com">barry@vonahsen.com</a>, <a class="moz-txt-link-abbreviated" href="mailto:ciapug@cialug.org">ciapug@cialug.org</a>, <a class="moz-txt-link-abbreviated" href="mailto:ciapug@cialug.org">ciapug@cialug.org</a>
Cc: Barry Von Ahsen <a class="moz-txt-link-rfc2396E" href="mailto:barry@vonahsen.com"><barry@vonahsen.com></a>
Message-ID:
<a class="moz-txt-link-rfc2396E" href="mailto:040420071642.12428.4613D55D0001D5DB0000308C219791332903010CD2079C080C03BF020A9C0401D3049D0E0C@mchsi.com"><040420071642.12428.4613D55D0001D5DB0000308C219791332903010CD2079C080C03BF020A9C0401D3049D0E0C@mchsi.com></a>
I agree that is annoying, but it is producing the correct answer when you use "===" and what appears to be an incorrect answer when you use "==". Since I have never used "===" for anything, that would explain why it exists and would also prove that what you are experiencing is the intended behavior. I could not begin to guess why they would want those two strings to be equal, but there must be some reason for it.
-------------- Original message ----------------------
From: Barry Von Ahsen <a class="moz-txt-link-rfc2396E" href="mailto:barry@vonahsen.com"><barry@vonahsen.com></a>
</pre>
<blockquote type="cite">
<pre wrap=""> echo "phpversion: ".phpversion()."<br>";
$a = "01234";
$b = "1234";
echo "a:". $a."<br>";
echo "b:". $b."<br>";
if($a == $b) { echo "a==b"; } else { echo "a!=b"; } echo "<br>";
if($a === $b) { echo "a===b"; } else { echo "a!==b"; } echo "<br>";
echo "gettype(a):". gettype($a)."<br>";
echo "gettype(b):". gettype($b)."<br>";
$c = "0foo";
$d = "foo";
echo "c:". $c."<br>";
echo "d:". $d."<br>";
if($c == $d) { echo "c==d"; } else { echo "c!=d"; } echo "<br>";
if($c === $d) { echo "c===d"; } else { echo "c!==d"; } echo "<br>";
output:
phpversion: 4.4.0
a:01234
b:1234
a==b
a!==b
gettype(a):string
gettype(b):string
c:0foo
d:foo
c!=d
c!==d
I totally understand why "01234"==1234, but not why "01234"=="1234". If
I'm doing string=>string, no conversion should happen. However, if it
does, why doesn't "0foo"=>0 and "foo"=>0 so "0foo"=="foo" also?!?
-barry
_______________________________________________
ciapug mailing list
<a class="moz-txt-link-abbreviated" href="mailto:ciapug@cialug.org">ciapug@cialug.org</a>
<a class="moz-txt-link-freetext" href="http://cialug.org/mailman/listinfo/ciapug">http://cialug.org/mailman/listinfo/ciapug</a>
</pre>
</blockquote>
<pre wrap=""><!---->
------------------------------
Message: 6
Date: Wed, 04 Apr 2007 16:44:23 +0000
From: <a class="moz-txt-link-abbreviated" href="mailto:carl-olsen@mchsi.com">carl-olsen@mchsi.com</a>
Subject: Re: [ciapug] yeah, weakly typed languages
To: <a class="moz-txt-link-abbreviated" href="mailto:barry@vonahsen.com">barry@vonahsen.com</a>, <a class="moz-txt-link-abbreviated" href="mailto:ciapug@cialug.org">ciapug@cialug.org</a>, <a class="moz-txt-link-abbreviated" href="mailto:ciapug@cialug.org">ciapug@cialug.org</a>
Cc: Barry Von Ahsen <a class="moz-txt-link-rfc2396E" href="mailto:barry@vonahsen.com"><barry@vonahsen.com></a>
Message-ID:
<a class="moz-txt-link-rfc2396E" href="mailto:040420071644.13932.4613D5E700067F0D0000366C219791332903010CD2079C080C03BF020A9C0401D3049D0E0C@mchsi.com"><040420071644.13932.4613D5E700067F0D0000366C219791332903010CD2079C080C03BF020A9C0401D3049D0E0C@mchsi.com></a>
It's taking a while for this to sink in. The difference between the strings is that one is all numeric characters and the other is mixed. Don't ask me why this makes a difference. I'm just pointing it out and accepting that it explains the difference.
-------------- Original message ----------------------
From: Barry Von Ahsen <a class="moz-txt-link-rfc2396E" href="mailto:barry@vonahsen.com"><barry@vonahsen.com></a>
</pre>
<blockquote type="cite">
<pre wrap=""> echo "phpversion: ".phpversion()."<br>";
$a = "01234";
$b = "1234";
echo "a:". $a."<br>";
echo "b:". $b."<br>";
if($a == $b) { echo "a==b"; } else { echo "a!=b"; } echo "<br>";
if($a === $b) { echo "a===b"; } else { echo "a!==b"; } echo "<br>";
echo "gettype(a):". gettype($a)."<br>";
echo "gettype(b):". gettype($b)."<br>";
$c = "0foo";
$d = "foo";
echo "c:". $c."<br>";
echo "d:". $d."<br>";
if($c == $d) { echo "c==d"; } else { echo "c!=d"; } echo "<br>";
if($c === $d) { echo "c===d"; } else { echo "c!==d"; } echo "<br>";
output:
phpversion: 4.4.0
a:01234
b:1234
a==b
a!==b
gettype(a):string
gettype(b):string
c:0foo
d:foo
c!=d
c!==d
I totally understand why "01234"==1234, but not why "01234"=="1234". If
I'm doing string=>string, no conversion should happen. However, if it
does, why doesn't "0foo"=>0 and "foo"=>0 so "0foo"=="foo" also?!?
-barry
_______________________________________________
ciapug mailing list
<a class="moz-txt-link-abbreviated" href="mailto:ciapug@cialug.org">ciapug@cialug.org</a>
<a class="moz-txt-link-freetext" href="http://cialug.org/mailman/listinfo/ciapug">http://cialug.org/mailman/listinfo/ciapug</a>
</pre>
</blockquote>
<pre wrap=""><!---->
------------------------------
Message: 7
Date: Wed, 04 Apr 2007 11:45:02 -0500
From: "Dave J. Hala Jr." <a class="moz-txt-link-rfc2396E" href="mailto:dave@58ghz.net"><dave@58ghz.net></a>
Subject: Re: [ciapug] yeah, weakly typed languages
To: PHP List <a class="moz-txt-link-rfc2396E" href="mailto:ciapug@cialug.org"><ciapug@cialug.org></a>
Message-ID: <a class="moz-txt-link-rfc2396E" href="mailto:1175705102.31767.15.camel@localhost.localdomain"><1175705102.31767.15.camel@localhost.localdomain></a>
Content-Type: text/plain
I *think* I saw that in reference to php 5 or soon to be php 6
somewhere...
On Wed, 2007-04-04 at 11:36, <a class="moz-txt-link-abbreviated" href="mailto:carl-olsen@mchsi.com">carl-olsen@mchsi.com</a> wrote:
</pre>
<blockquote type="cite">
<pre wrap="">I have never used this, but isn't "===" a function that might solve this?
I think "==" is equality, and "===" is absolute equality.
Carl
-------------- Original message ----------------------
From: Barry Von Ahsen <a class="moz-txt-link-rfc2396E" href="mailto:barry@vonahsen.com"><barry@vonahsen.com></a>
</pre>
<blockquote type="cite">
<pre wrap=""> echo "phpversion: ".phpversion()."<br>";
$a = "01234";
$b = "1234";
echo "a:". $a."<br>";
echo "b:". $b."<br>";
if($a == $b) { echo "a==b"; } else { echo "a!=b"; } echo "<br>";
if($a === $b) { echo "a===b"; } else { echo "a!==b"; } echo "<br>";
echo "gettype(a):". gettype($a)."<br>";
echo "gettype(b):". gettype($b)."<br>";
$c = "0foo";
$d = "foo";
echo "c:". $c."<br>";
echo "d:". $d."<br>";
if($c == $d) { echo "c==d"; } else { echo "c!=d"; } echo "<br>";
if($c === $d) { echo "c===d"; } else { echo "c!==d"; } echo "<br>";
output:
phpversion: 4.4.0
a:01234
b:1234
a==b
a!==b
gettype(a):string
gettype(b):string
c:0foo
d:foo
c!=d
c!==d
I totally understand why "01234"==1234, but not why "01234"=="1234". If
I'm doing string=>string, no conversion should happen. However, if it
does, why doesn't "0foo"=>0 and "foo"=>0 so "0foo"=="foo" also?!?
-barry
_______________________________________________
ciapug mailing list
<a class="moz-txt-link-abbreviated" href="mailto:ciapug@cialug.org">ciapug@cialug.org</a>
<a class="moz-txt-link-freetext" href="http://cialug.org/mailman/listinfo/ciapug">http://cialug.org/mailman/listinfo/ciapug</a>
</pre>
</blockquote>
<pre wrap="">
_______________________________________________
ciapug mailing list
<a class="moz-txt-link-abbreviated" href="mailto:ciapug@cialug.org">ciapug@cialug.org</a>
<a class="moz-txt-link-freetext" href="http://cialug.org/mailman/listinfo/ciapug">http://cialug.org/mailman/listinfo/ciapug</a>
</pre>
</blockquote>
</blockquote>
<br>
<br>
<pre class="moz-signature" cols="72">--
<><><><><><><><><><><><><><><><><>
Mike Parks
Captain Jack Communications
WebSite Development and Hosting
<a class="moz-txt-link-abbreviated" href="http://www.captainjack.com">www.captainjack.com</a>
Phone: 515-964-8500
Fax: 515-964-4685</pre>
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