[PHP] Why a while loop for printing SQL query results?

[burnttoastnice]

Why is a while loop used instead of an  if  or a foreach loop when fetching SQL query results? 

I'm using a SQLite database as well as PHP's SQLite3 class.

[Neil]

Because you want to loop while you still have data.

 

The thing returned by the mysqli functions, iirc, is a resource identifier, not actual data.

 

You use a while loop to go through it so that you pull the data each time you call your fetch (datatype), and the library internally increased the iterator. Once it's at the end of the iterator, it returns null, and the loop is therefore broken.

 

Is there a reason you need a for/each loop?

[burnttoastnice]

Because you want to loop while you still have data.

 

The thing returned by the mysqli functions, iirc, is a resource identifier, not actual data.

 

You use a while loop to go through it so that you pull the data each time you call your fetch (datatype), and the library internally increased the iterator. Once it's at the end of the iterator, it returns null, and the loop is therefore broken.

 

Is there a reason you need a for/each loop?

 

Not really any specific reason, was just curious as to why. Thanks

[MrBucket101]

Why is a while loop used instead of an  if  or a foreach loop when fetching SQL query results? 

I'm using a SQLite database as well as PHP's SQLite3 class.

foreach is meant for looping over arrays

 

So you will need to store the results of your SQL Query in an array before using the foreach.

Just adds an extra step, instead of just fetching the data row by row, and acting on each row.

[burnttoastnice]

foreach is meant for looping over arrays

 

So you will need to store the results of your SQL Query in an array before using the foreach.

Just adds an extra step, instead of just fetching the data row by row, and acting on each row.

 

If only the result was returned in a format suitable for converting into an array <_< I'll try your suggestion by looping it over and adding each row into an array.

[MrBucket101]

If only the result was returned in a format suitable for converting into an array <_< I'll try your suggestion by looping it over and adding each row into an array.

take a look into the fetchall command, you don't need to add each row into an array

From the manpage, mysqli_fetch_all() fetches all result rows and returns the result set as an associative array, a numeric array, or both.

[burnttoastnice]

take a look into the fetchall command, you don't need to add each row into an array

From the manpage, mysqli_fetch_all() fetches all result rows and returns the result set as an associative array, a numeric array, or both.

 

I'm not sure if that function is available for SQLite - but in future I'll be moving to a proper mySQL database so I'll keep this in mind.

[MrBucket101]

I'm not sure if that function is available for SQLite - but in future I'll be moving to a proper mySQL database so I'll keep this in mind.

From the manpage: 

 

sqlite_fetch_all() returns an array of the entire result set from the result resource. It is similar to calling sqlite_query() (orsqlite_unbuffered_query()) and then sqlite_fetch_array() for each row in the result set.