Update Table from Another Table in SQL Server: A simple scenario demonstrating how we can update Persons table with data from Employees table using update statement. A simple but very effective query which can saves you from creating unnecessary cursor for updating from different tables. By performance wise also Update statement is more efficient compared to creating update cursor.
Set DestTbl.ColumnABC = SourceTbl.ColumnXYZ
FROM Employees SourceTbl
JOIN Persons DestTbl
ON DestTbl.KeyCol1 = SourceTbl.KeyCol5
SourceTbl stands for Source Table
DestTbl stands for Destination Table