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:
Syntax:
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.
Example:
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) ;