Question

I’m having trouble inserting data from one column to another within the same table. I have no problem inserting individual rows but that is not what I want. I have a column called “PercentFull”, I am multiplying this value by .01 to get the decimal equivalent, which is what I want to be inserted into a column I’ve called “NewPercentFull”. I have tried the following:

insert into Table1 (NewPercentFull)
select PercentFull * .01
from Table 1

There is already data that populates the PercentFull column. However, after this query is executed, I get NULL for every column in my table, including the NewPercentFull. Anyone has an idea of how to achieve this? Thanks

Answer 1

Inserting data from one column, into another, from the same record, would involve using an UPDATE statement:

UPDATE Table1
SET NewPercentFull=PercentFull * .01

With your query, you should’ve seen double the amount of records in Table1 after execution of that query.

You’ve mentioned that the values were NULL even for NewPercentFull. If this is the case, then I think my query may return NULL values too. This will occur when PercentFull is also NULL.

To avoid this, only UPDATE records which don’t have a NULL value for PercentFull:

UPDATE Table1
SET NewPercentFull=PercentFull * .01
WHERE PercentFull IS NOT NULL