I would kindly request some help on T-SQL coding. I have a column with a list of conditions (WHERE statements). I need to extract a distinct list of column names with the aliases.

Example Data: 
ISNULL(ABC.Premium, 0) < 0,ISNULL(ABC.Date, 101) < 19

Result: 
ABC.Premium, ABC.Date

I am looking to do a string operation to:
1. search for the '.'
2. String operation to extract the name. 

I am not sure how to get the LOOP to search for multiple '.' and extract the column names.

```
CREATE DATABASE TEST
GO
    USE [Test]
    GO

    CREATE TABLE [dbo].[StringRetrival](
        [ID] [int] NOT NULL,
        [Condition] [varchar](4000) NULL
    ) ON [PRIMARY]

    GO

    INSERT [dbo].[StringRetrival] ([ID], [Condition]) VALUES (1, N'ISNULL(ABC.Premium, 0) < 0,ISNULL(ABC.Date, 101) < 19')
    GO
    INSERT [dbo].[StringRetrival] ([ID], [Condition]) VALUES (2, N'ISNULL(DEF.ColB, 101) < 25,ISNULL(DEF.ColB, 101) < 25,ISNULL(XYZ.ColB, 101) > 5, MSN.ColA < 5')
    GO
    INSERT [dbo].[StringRetrival] ([ID], [Condition]) VALUES (3, N'RTY.ColA')
    GO

```

I would appreciate your help on this. 

Thank you