---- Create Table 
      CREATE TABLE dbo.myTable
      (
        ID    int      NOT NULL,
        Name  char(23) NULL,
        City  char(30) NULL
      )
      GO


---- Alter Table (How to add New Columns; Drop and Alter existing Columns)
ALTER TABLE dbo.myTable      
      
 ---- Add a new column to the table 
   ADD DOB datetime NULL,
      
 ---- Drop Existing Column 
   DROP COLUMN City,
      
 ---- Alter Existing Column 
   ALTER COLUMN Name char(30),
      
 ---- Add a new PRIMARY KEY CONSTRAINT to the table 
   ADD CONSTRAINT PK_myTable PRIMARY KEY (ID)