SQL Job Interview Questions and Answers 1 :: What is SQL (Structured Query Language)? SQL is an English like language consisting of commands to store, retrieve, maintain & regulate access to your database.Read More 2 :: What is the SQL*Plus? SQL*Plus is an application that recognizes &...
and the outer query is known as the main query in the Database. The implementation of subqueries is always done first, and the outcome of the following is always passed on to the main query.
Softwaretesting-QuestionsandAnswers-SQLInterviewQuestions Q.WhatdoesSQLstandfor? A.StructuredQueryLanguage Q.Whatisaprimarykey? A.Primarykey:EachrowofthedatainatableuniquelyidentifiedbyaPrimaryKey Thecolumn(columns)thathascompletelyuniquedatathroughoutthetableis ...
The Microsoft SQL Server max degree of parallelism (MAXDOP) configuration option controls the number of processors that are used for the execution of a query in a parallel plan. This option determines the computing and threads resources that are used for the query plan operators that perform the ...
Linked Servers is a concept in SQL Server by which we can add other SQL Server to a Group and query both the SQL Server dbs using T-SQL Statements. With a linked server, you can create very clean, easy to follow, SQL statements that allow remote data to be retrieved, joined and combi...
You can avoid duplicates using UNION ALL and still run much faster than UNION DISTINCT (which is actually same as UNION) by running a query like this: SELECT * FROM mytable WHERE a=X UNION ALL SELECT * FROM mytable WHERE b=Y AND a!=X The key is the AND a!=X part. This gives ...
in a database application. A table scan happens when there is no index available to help a query. In a table scan SQL Server examines every row in the table to satisfy the query results. Table scans are sometimes unavoidable, but on large tables, scans have a terrific impact on ...
6. Difference betweenDDL,DQL,DML,DCL, andTCLStatements? SQL commands There are five main categories for the SQL commands: DDL –Data Definition Language– defines and alters the database schema; DQL –Data Query Language– performs the query operations on the data within schema objects; ...
Prepare with basic and advanced PL/SQL interview questions and answers, covering topics like functions, triggers, dynamic SQL, and error handling.
6. Can you write a query to find nth highest salary of an employee? 7. Write a query to delete duplicate records from a table. Note: Write queries that suits the below situation. A table is having a unique key and having duplicates records, table is not having a unique and having...