Alter every double fields of a table

问题

I need to change every double precision field of a table to numeric(15,3) type, how can i do this job quickly with a stored procedure that iterate through the field of a given table and if the type is double precision alter column to numeric ?

回答1:

following query should return query to update these tables... you can add table filter if you want. Copy the result and run it.

select 'ALTER TABLE ' + table_name + ' ALTER COLUMN ' + column_name + 'TYPE numeric(15,3)'  
  from information_schema.columns 
 where data_type = 'double precision' 
       and table_name = 'YOUR_TABLE_NAME'

TEST IT BEFORE RUN IT. I DID NOT TEST THIS YET.

回答2:

While another question will do it for all columns; a simple "alter table [tablename] alter column [columnToAlter] type numeric(15,3). You shouldn't need to run them through a cursor; any value that's not going to be affected by this should remain unaffected.

If you can't do it by changing the datatype itself, a simple update [tablename] set [columnname] = cast(columnname as numeric(15,3) should also work.

Hope that helps!

来源：https://stackoverflow.com/questions/6431564/alter-every-double-fields-of-a-table