How to add new column in existing table using sql server?

Ans.
Syntax:-

Alter Table [Table_Name] Alter Column [Column_Name] varchar(12)

Example:-

Alter table Table1 Alter Column Adddress varchar(50)

How to change schema of Tables in sql sever?

Ans.

Syntax:-

alter schema [new_schema] transfer [old_schema].[object_name];

Examples

Alter schema dbo transfer sys.table1

How to Alter "FOREIGN KEY" in existing table?

Ans.


ALTER TABLE [dbo].[Table2]  WITH CHECK ADD FOREIGN KEY([Dept_Id])
REFERENCES [dbo].[Table1] ([Dept_Id])