Tech Quick PHP question, random data and limits

[Publisher Bucks]

So i have a table that contains a range of columns, some of them fill the entire set of rows, some of them have say, 10 items in the column, while I have 25 rows.

This is the querie that I am using to display the data:

$sql = "SELECT ColumnName FROM Table ORDER BY RAND() LIMIT 1";

I understand why its only displaying blank fields in some areas of my PHP coding (because its randomly pulling row data that doesnt exist in a column), however, how would I change the above querie to FORCE data to be displayed for a specific column, whether its full or only 1/2 full with data?

Hopefully, that makes sense?

[sarettah]

Originally Posted by Publisher Bucks

So i have a table that contains a range of columns, some of them fill the entire set of rows, some of them have say, 10 items in the column, while I have 25 rows.

This is the querie that I am using to display the data:



I understand why its only displaying blank fields in some areas of my PHP coding (because its randomly pulling row data that doesnt exist in a column), however, how would I change the above querie to FORCE data to be displayed for a specific column, whether its full or only 1/2 full with data?

Hopefully, that makes sense?

If the empty fields are nulls then

Select field-name from table where field-name is no null order by rand() ....

Would work. If there are blank fields that are not null then

Select field-name from table where field-name>'' order by rand() ...

should work

.

[Publisher Bucks]

Originally Posted by sarettah

If the empty fields are nulls then

Select field-name from table where field-name is no null order by rand() ....

Would work. If there are blank fields that are not null then

Select field-name from table where field-name>'' order by rand() ...

should work

.

Thanks,

I've tried both but neither seems to work, the page still displays empty data for some reason :/

$sql = "SELECT Culumn FROM Table WHERE Column IS NULL ORDER BY RAND() LIMIT 1";

$sql = "SELECT Column FROM Table WHERE Column IS NOT NULL ORDER BY RAND() LIMIT 1";

The column has 4 rows of data on 20 rows.

All rows are currently 'null' in the table and are also set as 'longtext' (If that matters?)

[k0nr4d]

Null and empty are not the same thing. Null is used to refer to nothing and empty is a string with zero length.


SELECT * FROM table WHERE column != '' ORDER BY RAND() LIMIT 1

[Publisher Bucks]

Originally Posted by k0nr4d

Null and empty are not the same thing. Null is used to refer to nothing and empty is a string with zero length.


SELECT * FROM table WHERE column != '' ORDER BY RAND() LIMIT 1

Okay that works, thank you.

Any chance you could explain why for me though? What does that != do that a regular query doesnt?

[k0nr4d]

Originally Posted by Publisher Bucks

Okay that works, thank you.

Any chance you could explain why for me though? What does that != do that a regular query doesnt?

!= is a regular query. "!=" is "does not equal". You can use it in PHP as well, it is the opposite of "==" like you'd use in an if statement.
An empty string is not null, it's an empty string.

[Publisher Bucks]

Originally Posted by k0nr4d

!= is a regular query. "!=" is "does not equal". You can use it in PHP as well, it is the opposite of "==" like you'd use in an if statement.
An empty string is not null, it's an empty string.

Awesome, thanks for the extra tidbit of knowledge

[ZTT]

Originally Posted by k0nr4d

!= is a regular query. "!=" is "does not equal". You can use it in PHP as well, it is the opposite of "==" like you'd use in an if statement.
An empty string is not null, it's an empty string.

Though if you use != in PHP you'll find that null does equal an empty string.

[k0nr4d]

Originally Posted by ZTT

Though if you use != in PHP you'll find that null does equal an empty string.