Delete empty rows | 易学教程

问题

I use PostgreSQL database and in one table I have the datetime column edit_user. Some rows are blank, and these rows I would like to delete.

I tried

DELETE FROM table WHERE edit_user="";

but I got the error

LINE 1: delete from table where edit_user="";

Also, I thought in the column as a blank value could be 0000-00-00, but there isn't.

How I should execute this command correctly?

回答1:

DELETE FROM table WHERE edit_user IS NULL;

回答2:

If you are trying to delete empty spaces , try using ='' instead of is null. Hence , if your row contains empty spaces , is null will not capture those records. Empty space is not null and null is not empty space.

Dec  Hex     Binary    Char-acter Description
0    00  00000000      NUL        null

32  20  00100000      Space       space

So I recommend:

delete  from foo_table  where bar = ''

#or 

delete  from foo_table  where bar = '' or bar is null 

#or even better , 

delete from foo_table where rtrim(ltrim(isnull(bar,'')))='';

回答3:

I believe that your problem is that you're checking for an empty string using double quotes instead of single quotes. Try just changing to:

DELETE FROM table WHERE edit_user=''

回答4:

To delete rows empty in table

syntax:

DELETE FROM table_name 
WHERE column_name IS NULL;

example:

Table name: data ---> column name: pkdno

DELETE FROM data 
WHERE pkdno IS NULL;

Answer: 5 rows deleted. (sayso)

来源：https://stackoverflow.com/questions/10654614/delete-empty-rows

标签

sql

postgresql