Comparing Table Structure in ORACLE

You can use below SQL Queries to compare two tables based on your requirement:   Your content goes here. Edit or remove this text inline or in the module Content settings. You can also style every aspect of this content in the module Design settings and even...

ORACLE SQL Query Order of Operations

How ORACLE process the SQL Query? What is the SQL Query Logical Processing Order? Consider below Query clauses and understand how they get processed when executed in a form of a SQL Query:FROM JOINs GROUP by HAVING WHERE SELECT ORDER BY So, calculated SELECT columns...

Identify columns having all NULLs

There can be different ways and you can have a look on the below code will identify columns having all NULLs. Similarly, you can write it to Delete such columns from Table if you don’t want them in your table. Declare l_count Number; Begin For col In (Select...

ROWNUM Vs. ROWID

SELECT ID, ROWID, ROWNUM From EMP_TEST; ID ROWID ROWNUM 102 AAASd8AAEAAAAIcAAB 1 104 AAASd8AAEAAAAIcAAD 2 105 AAASd8AAEAAAAIcAAE 3 107 AAASd8AAEAAAAIcAAG 4 110 AAASd8AAEAAAAIcAAJ 5 103 AAASd8AAEAAAAIfAAA 6 106 AAASd8AAEAAAAIfAAB 7 108 AAASd8AAEAAAAIfAAC 8 109...