Need help selecting non-empty column values from MySQL
I have a MySQL table which has about 30 columns. One column has empty values for the majority of the table. How can I use a MySQL command to filter out the items which do have values in the table?
Here is my attempt:
SELECT * FROM `table` WHERE column IS NOT NULL
This does not filter be开发者_如何学JAVAcause I have empty cells rather that having NULL
in the void cell.
Also look for the columns not equal to the empty string ''
SELECT * FROM `table` WHERE column IS NOT NULL AND column <> ''
If you have fields containing only whitespace which you consider empty, use TRIM()
to eliminate the whitespace, and potentially leave the empty string ''
SELECT * FROM `table` WHERE column IS NOT NULL AND TRIM(column) <> ''
A alternate approach that also handles blank spaces in a column as well as null:
SELECT * FROM `table` WHERE TRIM(column) > ''
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