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Showing posts from August, 2022

Regular Expression in Oracle SQL

Regular Expression in Oracle SQL Regular Expression in Oracle SQL is a pattern matching technique to retrieve sort of data based on the conditions given in Oracle database. Pattern Matching is similar to functions like, replace, substring and in string which are previously seen topics. At the end of this article there will be certain task to practice for this Regular Expressions. It is very important to be very clear about this topic, this are very helpful for many interview Questions. Using regular expressions with Oracle Database: Overview Regular Expression is one of the easiest way to learn with clear understanding if one are familiar with the below Basic string matching patterns, Quantifiers, Meta characters, Functions etc. Note : The above points should understand clearly means it will be very easy to write a query. Basic String Matching with Regular Expressions | Either or  () Group \ Escape ^ Start $ Stop Literals of regular expression in oracle sql [ a b c ] a, b, c [^ a

Create a sequence in Oracle with clear explanation

Introduction to Create a Sequence in Oracle As we discussed the schema objects in the previous session, so in this session that we are going to see one of the schema objects. This is very important topic that most of the interview questions are comes from here. At the end of this session, you will be very clear about the below topics related to the sequence: What is Sequence in Oracle ? Importance of creating sequence in Oracle Syntax for creating sequence in Oracle Data Dictionary for sequences. How to reset the sequence in Oracle ? How to alter the sequence in Oracle ? How to drop the sequence in Oracle ? NOTE : Answer the Interview Questions at the end of the article What is Sequence in Oracle ? Sequence is a numeric value generator which is used to generate the numbers in a sequential order by the incremental order. It is mostly used to generate the primary key value. Importance of creating sequence in Oracle It is a schema Objects and it is also a sharable objects Can able to crea

Class 2.3 Statements in Oracle TCL

Statements in Oracle TCL Statements in Oracle TCL is one of the most important part in the subset of Oracle statements. TCL means Transaction Control Language. There is more chance that there will be a interview questions in this section. Before reading this article one should know more differences between DDL and DML commands which are already posted before. What is mean by Transaction ? Transaction means an event that takes place between two commit points, For example : In Retail words, the transaction means buying and selling any goods so that complete event is called as transaction. What is mean by Failed Transaction ? Failed Transaction means thus that event is failed to achieve the commit point after the event starts. For example: If you sending any amount in online transaction means due to some technical issues there will be failed to achieve the commit points in other side so that event is called as failed transaction. This TCL is mainly related to the above two questions onl