Category: Education

SQL

SQL Formula (Math Functions)

If you want to calculate a value with a function which is stored in the table (row or column) you can use the follwing code to execute the math formula. Replace placeholders with the...

SQL

Autonomous Transactions

PL/SQL normally treads the whole modification as a single transaction. If you want to have some part of the code as seperate transaction, you can use the functionallity of autonomous transactions. The statement PRAGMA...

SQL

SQL Aggregation

Aggregation Cube If you have dimensions, you can use the cube function. Imagine you have the dimensions time, state and product. When you use the cube function, you can get an insight of these...

Schreibschutz von Tabellen 1

Write protection of tables

Write protection can be applied to tables. This prevents DDL (Data Definition Language) and DML (Data Manipulation Language) changes during maintenance mode. The statement: ALTER TABLE tablename READ ONLY; — nur mehr lesbar ALTER...

NVL NVL2

Difference between SQL NVL and NVL2

NVL VS NVL2 The difference between the SQL functions NVL and NVL2 is, that when using the function NVL2 you can set different values for NULL and NOT NULL. NVL only checks and analyzes...