将数据类型varchar转换为数字时出错（新手）

Question

I am new to this so be gentle. I am running this script to update a column that's blank with a 108. The column is set to numeric(18, 0) . why am I getting this message and how can I get past it.

Update HL7ManagerRecords
set ScheduleID = 108
where ScheduleID =''

Answer 1

Could be the fields is null

Update HL7ManagerRecords
set ScheduleID = 108
where ScheduleID is null 

Answer 2

The column ScheduleID is set to numeric(18, 0) but you try to find all records where ScheduleID equals an empry string: where ScheduleID ='' .

Use IS NULL instead

Update HL7ManagerRecords
set ScheduleID = 108
where ScheduleID IS NULL 

Answer 3

You will need to post the schema for the Table. My assumption is ScheduleID is a numeric. Since it is a numeric the ScheduleID is not blank, because it holds a number numeric MSDN . My assumption is it is null , because that is the default value if you create a numeric column and do not specify if it is null or not. So what you will need to do is

Update HL7ManagerRecords
set ScheduleID = 108
where ScheduleID is null

Answer 4

If for some reason down the line you need to take a numeric data type and treat it as a blank string or change it to a string with a specific value, you could use something like ISNULL(ScheduleID,'') = ''. Like the other guys said, "is null" will work just fine, just another way to do it.