SQL. Changes require the table to be recreated
There is a table full which contains data. Is it possible to change field from [not null] to [null] without dropping and recreating it? SQL writes that table have to be dropped and recreated. :)
You can try:
alter table YourTable alter column YourColumn int null
Per Martin Smiths comment, a change in nullability does not require a copy of the table. On disk, each row has a nullabiltiy bitmap at the start. I thought the bitmap had to be resized in some cases, but apparently it contains a bit for each column, nullable or not nullable.
您是否尝试过使用ALTER TABLE XXX ALTER COLUMN YYY YOURTYPE NULL
命令?
这可能有助于:
ALTER TABLE [Table] ALTER COLUMN [Column] [YourDataType] NULL
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