Update method is used to update existing records in a table.

Note: Be careful when updating records in a table! Notice the WHERE clause in the UPDATE statement. The WHERE clause specifies which record(s) should be updated. If you omit the WHERE clause, all records in the table will be updated! Syntax 
		Update( x =>
			x.From( Table | SubSelect )
			 .LeftJoin( (Table | SubSelect), Condition )
			 .RightJoin( (Table | SubSelect), Condition )
			 .InnerJoin( (Table | SubSelect), Condition )
			 .Where( Condition )

			 .SetModel( model )
			 .Set( Field , value )
			 .SetRaw( Field , Expression )
			 .SetNull( Field ) )
		)
Examples Regular

Using SET

With Join