SQL Interview Questions Our schema We'll be going through six questions covering topics like query performance, joins, and SQL injection. They'll refer to the same database for cakes, customers, and orders at a bakery. Here's the schema: CREATETABLEcakes(cake_idINTNOTNULLAUTO_INCREMENTPRIMARY...
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.
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 &...
But some general issues that you could talk about would be: No indexes, table scans, missing or out of date statistics, blocking, excess recompilations of stored procedures, procedures and triggers without SET NOCOUNT ON, poorly written query with unnecessarily complicated joins, too much ...
SQL - Interview QuestionsSQL - JOINThe SQL JOIN clause is used to combine rows of two or more tables based on common column between them. There are four types of JOINs in SQL: INNER JOIN: It is sometimes called simple JOIN. It returns records based on matching rows in both tables. LEFT...
query. Q.Whatiscorrelatedsub-query? ACorrelatedsub_queryisasub_querywhichhasreferencetothemain query. Q. What is an Integrity Constraint ? A Integrity constraint is a rule that restricts values to a column in a table. Q. What is Referential Integrity ?
SQL Query: Select b.Department_ID,b.Department_name from Employee a,Department b where a.Department_id <> b.Department_ID; The Above Query will return following output: 102COGNOS These kind of real life scenarios we need to face in day to day life. I will explain other joins in next ...
SQL Joins 14. Explain Self-Join with an Example The self-join meansjoining one table with itself. We can use the Self-Join on a table only if it has a column (we will call it A) that serves as the primary key and another column (that we will call Y) that stores values that can...
The FULL OUTER JOIN combines results from both left and right outer joins. It returns all records from both tables, filling in NULL where no matches exist. The query below returns all records for the employees and departments table, even with unmatched rows. -- Combine all employees and depar...
4. How to find the query running on a given SPID? 5. What is XACT_ABORT ON? 6. Can we use two CTE’s in a single select query? 7. What are the different join operators in SQL Server? 8. Can we use a table variable inside a nested stored procedure if the table variable created...