How do mysql_fetch_assoc/mysql_query work?

[smythe70]

How do mysql_query() and mysql_fetch_assoc() actually work?

When I submit a query to a MySQL database it goes away, works out what
I requested and throws it back at me. When I submit a query using PHP I
submit the query using mysql_query and then iterate through the result
set sing mysql_fetch_assoc() (or mysql_fetch_array() or
mysql_fetch_row()). What is the purpose of mysql_fetch_xxxx()? Why
can't mysql_query return a two dimensional array? What trickery is
going on?

[Jerry Stuckle]

sm******@hotmail.com wrote:

How do mysql_query() and mysql_fetch_assoc() actually work?

When I submit a query to a MySQL database it goes away, works out what
I requested and throws it back at me. When I submit a query using PHP I
submit the query using mysql_query and then iterate through the result
set sing mysql_fetch_assoc() (or mysql_fetch_array() or
mysql_fetch_row()). What is the purpose of mysql_fetch_xxxx()? Why
can't mysql_query return a two dimensional array? What trickery is
going on?

Maybe you don't want a 2D array? And what happens if the database
returns a few hundred K rows? Or even a 1k rows with 10K data in each
row. You can rapidly use up a lot of memory that way.

Most of the time I only access one row at a time, and don't need to go
back to a previous row anyway. And when I do I can put everything (or
at least the data I want) in an array.

It also gives me the ability to access the data by the relative position
in the returned row, by the column name, or both. And if I only need
one [i.e. column name], it's more efficient to use only one.

And I'm not sure which language you're talking about when you say " When
I submit a query to a MySQL database it goes away, works out what I
requested and throws it back at me.". Even in C/C++ you need to use
mysql_fetch_row. What language are you using?

--
==================
Remove the "x" from my email address
Jerry Stuckle
JDS Computer Training Corp.
js*******@attglobal.net
==================

[universalbitmapper]

Jerry Stuckle wrote:

sm******@hotmail.com wrote:

How do mysql_query() and mysql_fetch_assoc() actually work?

When I submit a query to a MySQL database it goes away, works out what
I requested and throws it back at me. When I submit a query using PHP I
submit the query using mysql_query and then iterate through the result
set sing mysql_fetch_assoc() (or mysql_fetch_array() or
mysql_fetch_row()). What is the purpose of mysql_fetch_xxxx()? Why
can't mysql_query return a two dimensional array? What trickery is
going on?

Maybe you don't want a 2D array? And what happens if the database
returns a few hundred K rows? Or even a 1k rows with 10K data in each
row. You can rapidly use up a lot of memory that way.

Most of the time I only access one row at a time, and don't need to go
back to a previous row anyway. And when I do I can put everything (or
at least the data I want) in an array.

It also gives me the ability to access the data by the relative position
in the returned row, by the column name, or both. And if I only need
one [i.e. column name], it's more efficient to use only one.

And I'm not sure which language you're talking about when you say " When
I submit a query to a MySQL database it goes away, works out what I
requested and throws it back at me.". Even in C/C++ you need to use
mysql_fetch_row. What language are you using?

--
==================
Remove the "x" from my email address
Jerry Stuckle
JDS Computer Training Corp.
js*******@attglobal.net
==================

I think it's the SQL language?
I think it's not a question of arrays and memory used, it's the
difference between procedural and non-procedural.
Maybe there should be some kind of textarea gizmo in php/html
that just yields brute results like the MySQL console does.

[Jerry Stuckle]

universalbitmapper wrote:

Jerry Stuckle wrote:

>>sm******@hotmail.com wrote:

>>>How do mysql_query() and mysql_fetch_assoc() actually work?

When I submit a query to a MySQL database it goes away, works out what
I requested and throws it back at me. When I submit a query using PHP I
submit the query using mysql_query and then iterate through the result
set sing mysql_fetch_assoc() (or mysql_fetch_array() or
mysql_fetch_row()). What is the purpose of mysql_fetch_xxxx()? Why
can't mysql_query return a two dimensional array? What trickery is
going on?

Maybe you don't want a 2D array? And what happens if the database
returns a few hundred K rows? Or even a 1k rows with 10K data in each
row. You can rapidly use up a lot of memory that way.

Most of the time I only access one row at a time, and don't need to go
back to a previous row anyway. And when I do I can put everything (or
at least the data I want) in an array.

It also gives me the ability to access the data by the relative position
in the returned row, by the column name, or both. And if I only need
one [i.e. column name], it's more efficient to use only one.

And I'm not sure which language you're talking about when you say " When
I submit a query to a MySQL database it goes away, works out what I
requested and throws it back at me.". Even in C/C++ you need to use
mysql_fetch_row. What language are you using?

--
==================
Remove the "x" from my email address
Jerry Stuckle
JDS Computer Training Corp.
js*******@attglobal.net
==================

I think it's the SQL language?
I think it's not a question of arrays and memory used, it's the
difference between procedural and non-procedural.
Maybe there should be some kind of textarea gizmo in php/html
that just yields brute results like the MySQL console does.

Nope, mysql_fetch_array isn't a part of the language :-).

SQL defines the queries to be used. But each database has its own
interface to the application, and they typically vary somewhat between
languages.
--
==================
Remove the "x" from my email address
Jerry Stuckle
JDS Computer Training Corp.
js*******@attglobal.net
==================