Avoid multiple UNION when you want to write better SQL query. Always better to USE case statement this improves performance. Read more.
The power of RDBMS depends on certain rules placed. These rules are called as integrity rules. Those are entity integrity and referential integrity.
You all know RENAME clause in SQL is highly useful to change the name of Table, Index or other objects. Given here why this clause is used and syntax and Rules presented for ORACLE and DB2 databases.
The best example for Java stored procedure in DB2, also given java class path to write stored procedure and explained how to include it in the DB2 stored procedure standard block. Read more.
The best way of writing SQL select query in SQL to avoid ambiguous column issue. Mostly people confuse with alias concept. This SQL query using alias in SELECT is beneficial to apply in your current project.
The top 10 SQL questions on functions given in a Quiz format. Highly useful for SQL developers to apply this knowledge in your project directly. Read more.
The syntax as given in Oracle built-in function, it is to convert lower case letters into upper case letters. The explanation given here is with examples. So that you use in your SQL program directly.
The main advantage of REPLACE function is SQL is to replace a string with another string. Read more.
How to modify SQL in best way is I have given in this post two options. You can choose appropriately.
The best 1000 SQL queries to practice daily. Read more.