We use grep command to search for strings in the Unix Operation system. Now the same things on Windows can be done using these three free tools. These tools can do many work same as Grep command. Find command Lets check out some command tasklist|find “notepad” The below command searches for string in all the files ending .txt find “string name” *.txt findstr command It … Continue reading Grep equivalent in Windows to search text
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
Sometimes 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 ( Sql Joins) is a query that combines rows from … Continue reading What are Oracle Joins (Sql Joins)?
Using Sql Set Operators(Union,Union All,Intersect and Minus/Except) Sql Set operators can be used to select data from multiple tables. They combine the results of two or more queries. When using the Set operators a) Each SELECT clause must have the same number of column b) Column must be of same data-type c) Column should be specified in the same order in all the select clauses. … Continue reading Sql Set Operators: Union,Union All,Intersect and Minus
Last updated on June 23rd, 2018 at 07:11 amWhat is materialized views in oracle A materialized view is a database object that contains the results of a query. It is different from simple view .These materialized view have data stored and when you query the materialized view,it returns data from the data stored. The FROM clause of the query can name tables, views, and other … Continue reading what is materialized views in oracle?
ORA-00904: invalid identifier is one of the common error seen. Reference: Oracle documentation One of the most common cause of this error Invalid identifier means the column name entered is either missing or invalid. It also Some time comes when you used reserved word in Oracle database. Check List to resolve the ORA-00904 error It comes when you put extra comma in the create table … Continue reading How to resolve ORA-00904: invalid identifier
Useful and common MySQL queries for the developer and DBA’s 1)How to create mysql database mysql> create database techdb; mysql> use techdb; 2) How to create table in mysql database? .How to show the structure of the table after creation Here is the example for table creation in MySQL database 1) We need to first get into database use techdb; 2) Create table using below … Continue reading Most Common MySQL queries
Introduction to sed command in Unix/Linux sed – Stream EDitor – works as a filter processing input line by line. Sed reads one line at a time, chops off the terminating newline, puts what is left into the pattern space (buffer) where the sed script can process it (often using regular expressions), then if there anything to print – sed appends a newline and prints … Continue reading Awesome sed command in Linux/Unix with examples
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
Last updated on June 21st, 2018 at 07:03 am Oracle DBA need to operate on Unix/Linux/Solaris/AIX Operating system. He has to locate various file, process, kill session ,clear directories, schedule cron and various other activities. Here in this article I am trying to give some Useful Unix command for Oracle DBA to help them in day-to-day activities.These same commands are applicable for Linux also. Hope you … Continue reading Useful Unix/Linux command for Oracle DBA
Last updated on June 21st, 2018 at 06:14 amAwk is a powerful command. In this post,i will try to put awk command in unix/Linux with 21 examples Table of content What is awk command in Unix/linux How awk command in Unix/linux works What is awk patterns What is awk fields: What is awk records What is Awk command Working Methodology 21 awk command examples in … Continue reading 21 awk command examples in Unix/Linux
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