Replace null values with just a blank

Question

I currently have a sql statement that outputs data into an excel document. However, every time there is a cell that doesn't have data, it outputs NULL into the cell. I was wondering if there was a way that I could replace NULL with just a blank space? Someone suggested using coalesce to do this, however I haven't ever had the chance to use it so I will have to do some reading on it. Anyone have any other suggestions?

Answer 1

In your select you can put an IsNull/IfNull round the column. Not particularly efficient but does what you want.

MS SQL

Select IsNull(ColName, '') As ColName From TableName 

MySQL

Select IfNull(ColName, '') As ColName From TableName 

Answer 2

IFNULL is an Oracle extension (adopted by many other platforms). The "standard" SQL function is coalesce():

SELECT COALESCE(columnName, ' ') AS ColumnName
FROM tableName;