In SQL, the LAST_VALUE function is used to fetch the last value in a series of values within a specific partition and order. It can be particularly useful when used alongside the SET statement to update a column with the last value from a certain order.

Here’s an example of how to use LAST_VALUE with a SET statement in SQL:

UPDATE your_table
SET column_name = 
  (SELECT LAST_VALUE(column_name) OVER (PARTITION BY partition_column ORDER BY order_column)
   FROM your_table);

Let’s break down the above SQL statement:

1. The UPDATE statement is used to modify data in the specified table your_table.
2. The SET statement assigns a new value to the column_name column.

3. The subquery (SELECT LAST_VALUE(column_name) OVER (PARTITION BY partition_column ORDER BY order_column) FROM your_table) selects the last value from the column_name column using the LAST_VALUE function.

   • LAST_VALUE(column_name) selects the last value of the column_name.
   • OVER (PARTITION BY partition_column ORDER BY order_column) defines the partition and order criteria for the LAST_VALUE function.
     • PARTITION BY divides the rows into different partitions based on the values of the partition_column.
     • ORDER BY specifies the column used for ordering the rows within each partition. The last value will be determined based on this order.
   • FROM your_table specifies the table from which the column value is being selected.

By executing this SQL statement, the column_name column in the your_table table will be updated with the last value from the specified partition and order.

Remember to replace your_table with the actual name of the table, column_name with the specific column name you want to update, partition_column with the column used for partitioning, and order_column with the column used for ordering the rows.

By using the LAST_VALUE function with the SET statement, you can easily update a column with the last value from a specific order within a partition. This can be handy when you want to update records with valuable information without manually specifying the values yourself.

#SQL #LastValue