The PL/SQL Merge statement is a powerful tool that can be used to insert, update, or delete data in a database table.
The MERGE statement is used to merge two or more rows into one row. This is useful when you want to update or insert data into a table, and the data already exists in another table.
The syntax for the MERGE statement is as follows:
MERGE INTO first_table t1 USING second_table t2 ON (t1.column_id = t2.column_id) WHEN MATCHED THEN UPDATE SET column1 = value1, column2 = value2 WHEN NOT MATCHED THEN INSERT (column1, column2,...) VALUES (value1, value2, ...) ;
The PL/SQL Merge statement is a very powerful tool that can be used to make changes to a database table. When used correctly, it can save you a lot of time and effort. For example, you can use the MERGE statement to update customer information in one table with customer information from another table.
MERGE INTO customers c1 USING new_customers c2 ON (c1.customer_id = c2.customer_id) WHEN MATCHED THEN UPDATE SET name = c2.name, city = c2.city WHEN NOT MATCHED THEN INSERT (name, city) VALUES (c2.name, c2.city) ;