Category Archives: Oracle Sql

Sql  stands for Structured Query Language. is the language to communicate with  the rdbms.  plsql is the programming part of sql

Oracle sql and plsql are the languages which are widely used. They are easy to learn and apply. Here I would be listing out all the articles on Oracle sql and plsql

I am starting the basics so it is very helpful for the beginners to run sql and plsql here

 

How to use Oracle LISTAGG Function

Oracle LISTAGG function is an analytical function which allows us to concatenate the strings for measure_column for each GROUP based on the order_by_clause. This is present in Oracle from 11gR2 The syntax for the LISTAGG function in Oracle is LISTAGG (measure_column [, ‘delimiter’]) WITHIN GROUP (order_by_clause) [OVER (query_partition_clause)] Explanation of terms measure_column The column or expression whose values you wish to concatenate together in the … Continue reading How to use Oracle LISTAGG Function »

How to Solve ORA-00942 table or view does not exist

Last updated on July 26th, 2018 at 09:13 amORA-00942 is one of the many errors which Oracle developer ,DBA often gets. Lets first look at the OERR output Cause: The table or view entered does not exist, a synonym that is not allowed here was used, or a view was referenced where a table is required. Existing user tables and views can be listed by querying … Continue reading How to Solve ORA-00942 table or view does not exist »

Sql Subqueries : Single, Multiple, Scalar and Correlated

Sql SubQueries 1) A Subquery or Nested query is a query within another SQL query and embedded within the WHERE clause. A subquery is a query within a query 2) A subquery is used to return data that will be used in the main query as a condition to further restrict the data to be retrieved. 3) Subqueries answer the queries that have multiple parts. … Continue reading Sql Subqueries : Single, Multiple, Scalar and Correlated »

What are Oracle Joins (Sql Joins)?

Last updated on July 22nd, 2018 at 05:59 pmSometimes you need to display data from multiple tables. In order to perform that you need to link one table to another table.There are various ways in which we can obtain data from Multiple tables.Here I would be focusing on Oracle Joins.This is valid for in general any Sql Joins also Oracle Joins A Oracle Joins ( … Continue reading What are Oracle Joins (Sql Joins)? »

How to resolve ORA-00904: invalid identifier

Last updated on August 8th, 2018 at 05:24 amORA-00904: invalid identifier is one of the common error seen. You might get creating tables, selecting from tables and many more. It most happens because of the syntax issue. We have to be very careful with the syntax. The key is to remember syntax and write the code  correctly. You might want to check the Sql tutorials … Continue reading How to resolve ORA-00904: invalid identifier »

How to use Oracle SQL*Plus

Here in this post,I would be giving introduction to Oracle sqlplus  which is Oracle tools to connect to database  and how to download Oracle sqlplus Oracle SQL*Plus What is Oracle Sql*plus: 1) SQLPlus, widely used by DBAs and developers, is a powerful and straightforward tool from Oracle to interact with the database. 2) SQLPlus has its own formatting commands to make your queries look better, … Continue reading How to use Oracle SQL*Plus »

how to write sql queries

Last updated on June 21st, 2018 at 05:59 pm What is SQL? Relational Database Management system(RDBMS) contains many tables . These tables are the basic storage in Database. Tables contains the information about something in the real world for example customers ,employees ,deptTables in the database contain zero to many rows. SQL which stands for “Structured Query Language” which is pronounced as “SQL” or “sequel … Continue reading how to write sql queries »

How to resolve ORA-06512 at line num

Last updated on July 26th, 2018 at 09:31 amDescription of ORA-06512 ORA-06512  is one of the common error seen in PLSQL programs. Here is what documentation says about this error Reference :Oracle documentation Explanation of the ORA-06512 error: Error Ora-06512 means the backtrace message as the stack is being unwound by unhandled exceptions in your PLSQL code. This is a catch-all error for All PLSQL … Continue reading How to resolve ORA-06512 at line num »

ORA-00911: invalid character Common Issues and Resolution

Last updated on July 26th, 2018 at 09:33 amAs per OERR,ORA-00911: invalid character Cause: identifiers may not start with any ASCII character other than letters and numbers. $#_ are also allowed after the first character. Identifiers enclosed by double quotes may contain any character other than a double quote. Alternative quotes (q’#…#’) cannot use spaces, tabs, or carriage returns as delimiters. For all other contexts, … Continue reading ORA-00911: invalid character Common Issues and Resolution »

How to use external tables in Oracle with example

Last updated on June 21st, 2018 at 04:49 pmExternal table is one of the important feature in oracle , we will exploring external table in oracle with example in this post What are EXTERNAL TABLES in Oracle? 1)External tables are read only tables where the data is stored in flat files outside the database 2) You can user external table feature to access external files as … Continue reading How to use external tables in Oracle with example »

Oracle Create table Syntax,Tip and Examples

Last updated on July 26th, 2018 at 12:11 pm This article talks how to create table in Oracle,create table syntax in oracle,Examples,how to drop the table,truncate table etc. This will be very useful for Oracle DBA’ s and Developer both.They play with it many times in the day and an good knowledge can definitely help them expedite the task.They often get confused the datatype and … Continue reading Oracle Create table Syntax,Tip and Examples »

How to delete duplicate rows from Oracle table

Last updated on July 26th, 2018 at 09:37 amWe often need to find  and delete duplicate rows from oracle table due to many reasons in the database. We need to delete to clear off the data issues often. There are many ways to oracle delete duplicate rows but keep original .I would be showing off few  faster method to achieve it in this post. Please note … Continue reading How to delete duplicate rows from Oracle table »