See the Wiki article for an explanation and a suggested alternative structure if that is the case en. Show 5 more comments. Active Oldest Votes. Martin Smith Martin Smith k 81 81 gold badges silver badges bronze badges.
Thanks a lot.. It helped : — DfrDkn. For not-so-expert people, can you explain the last solution? What does the CASE statement try to accomplish?
And you are doing an inner join, not a cross join, right? I don't think this answers the question. It sounded like OP wanted to select I assume one specific row but exclude all columns from that result that were null - this answer requires you to either specify which columns aren't allowed to be null which is a different problem entirely or specify all columns, unsuitable for tables with many columns — csey.
Show 2 more comments. Mark Byers Mark Byers k gold badges silver badges bronze badges. Im not sure if I explained it well enough, but im gonna try a little better. Maybe provide a bit of example data in your question as it is not clear from your comment above whether this is all one column. But I want it to only return the column values that are not null.
Right now I do it with a loop to filter out the values after it returns the result. For retrieving data of only a set of columns, you have to mention the column names separated by commas as shown in following example. WHERE clause is used for specifying conditions. When more than one condition need to be specified and all of them need to be true, use AND operator to combine the conditions. When not all conditions need to be true and at least one condition becoming true is enough, use OR operator.
In web applications, there are cases that you need to do partial matching. One good example is the auto-completion text boxes. There when you type few letters, suggestions are presented for typed letters. These operators are case in-sensitive. Look at the column name of retrieved result set of following query. When the column names are too lengthy or want to have memorable names to be used in your PHP scripts , you can rename the column names of retrieved result sets with AS keyword.
In all above SQL queries, all the rows that matched given conditions are returned. But in web applications, you will need to limit the number of rows returned mainly for following reasons. LIMIT clause can be given one or two parameters separated by a comma.
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There are other columns that I do not need counted, so I can't select all. Add a comment. Active Oldest Votes. Haim Evgi k 45 45 gold badges silver badges bronze badges. Mark Byers Mark Byers k gold badges silver badges bronze badges. I'm having a hard time getting this to work. It's returning "1" as a value no matter how many columns I add.
I need it to give me the sum of the of columns that are not NULL. This didn't work for me either. It appears to count the number of rows that have at least one non-null column. The question is asking about the number of columns in each row that are not null. Stephen Ostermiller Stephen Ostermiller If performance matters you need to benchmark both variants to see which outperforms the other.
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