This is a one-liner, you just need to use the axis argument for min to tell it to work across the columns rather than down: df[‘Minimum’] = df.loc[:, [‘B0’, ‘B1’, ‘B2’]].min(axis=1) If you need to use this solution for different numbers of columns, you can use a for loop or list comprehension to construct the … Read more
The reason is that the query optimizer does not do a very good job at costing user-defined functions. It decides, in some cases, that it would be cheaper to completely re-evaluate the function for each row, rather than incur the disk reads that might be necessary otherwise. SQL Server’s costing model does not inspect the … Read more
“Persisted” means “stored physically” in this context. It means that the computed value is computed once on insert (and on updates) and stored on disc, so it does not have to be computed again on every select. Persisted also causes a performance penalty on insert and updates, since the column must be computed, but will … Read more
Something like this: ALTER TABLE dbo.MyTable DROP COLUMN OldComputedColumn ALTER TABLE dbo.MyTable ADD OldComputedColumn AS OtherColumn + 10 Source
Use pandas.DataFrame.abs(). import pandas as pd df = pd.DataFrame(data={‘count’:[1, -1, 2, -2, 3, -3]}) df[‘count’] = df[‘count’].abs() print(df) count #0 1 #1 1 #2 2 #3 2 #4 3 #5 3
You can define a function which returns your different states “Full”, “Partial”, “Empty”, etc and then use df.apply to apply the function to each row. Note that you have to pass the keyword argument axis=1 to ensure that it applies the function to rows. import pandas as pd def alert(row): if row[‘used’] == 1.0: return … Read more
You could create a user-defined function for this: CREATE FUNCTION dbo.GetValue(@ncode INT, @recid INT) RETURNS INT AS SELECT @recid * nvalue FROM c_const WHERE code = @ncode and then use that to define your computed column: ALTER TABLE dbo.YourTable ADD NewColumnName AS dbo.GetValue(ncodeValue, recIdValue)
You can create computed columns in your database tables. In the EF model you just annotate the corresponding properties with the DatabaseGenerated attribute: [DatabaseGenerated(DatabaseGeneratedOption.Computed)] public double Summ { get; private set; } Or with fluent mapping: modelBuilder.Entity<Income>().Property(t => t.Summ) .HasDatabaseGeneratedOption(DatabaseGeneratedOption.Computed) As suggested by Matija Grcic and in a comment, it’s a good idea to make … Read more
You just need to create it with schemabinding. SQL Server will then verify whether or not it meets the criteria to be considered as deterministic (which it does as it doesn’t access any external tables or use non deterministic functions such as getdate()). You can verify that it worked with SELECT OBJECTPROPERTY(OBJECT_ID(‘[dbo].[FullNameLastFirst]’), ‘IsDeterministic’) Adding the … Read more