SQL (Structured Query Language) Interview Preparation Guide
Sharpen your SQL interview expertise with our handpicked 172 questions. Each question is crafted to challenge your understanding and proficiency in SQL. Suitable for all skill levels, these questions are essential for effective preparation. Secure the free PDF to access all 172 questions and guarantee your preparation for your SQL interview. This guide is crucial for enhancing your readiness and self-assurance.172 SQL 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.
2 :: What is the SQL*Plus?
SQL*Plus is an application that recognizes & executes SQL commands & specialized SQL*Plus commands that can customize reports, provide help & edit facility & maintain system variables.
3 :: What is NVL?
NVL : Null value function converts a null value to a non-null value for the purpose of evaluating an expression. Numeric Functions accept numeric I/P & return numeric values. They are MOD, SQRT, ROUND, TRUNC & POWER.
4 :: What is a Character Functions?
Character Functions are INITCAP, UPPER, LOWER, SUBSTR & LENGTH. Additional functions are GREATEST & LEAST. Group Functions returns results based upon groups of rows rather than one result per row, use group functions. They are AVG, COUNT, MAX, MIN & SUM.
5 :: What is SET?
SET command changes the system variables affecting the report environment.
6 :: What is a TTITLE & BTITLE?
TTITLE & BTITLE are commands to control report headings & footers.
7 :: What is sql BREAK?
BREAK command clarify reports by suppressing repeated values, skipping lines & allowing for controlled break points.
8 :: What is sql JOIN?
JOIN is the form of SELECT command that combines info from two or more tables.
Types of Joins are Simple (Equijoin & Non-Equijoin), Outer & Self join.
Equijoin returns rows from two or more tables joined together based upon a equality condition in the WHERE clause.
Non-Equijoin returns rows from two or more tables based upon a relationship other than the equality condition in the WHERE clause.
Outer Join combines two or more tables returning those rows from one table that have no direct match in the other table.
Self Join joins a table to itself as though it were two separate tables.
Types of Joins are Simple (Equijoin & Non-Equijoin), Outer & Self join.
Equijoin returns rows from two or more tables joined together based upon a equality condition in the WHERE clause.
Non-Equijoin returns rows from two or more tables based upon a relationship other than the equality condition in the WHERE clause.
Outer Join combines two or more tables returning those rows from one table that have no direct match in the other table.
Self Join joins a table to itself as though it were two separate tables.
9 :: What is sql COMPUTE?
command control computations on subsets created by the BREAK command.
10 :: What is SQL*Loader?
SQL*Loader is a product for moving data in external files into tables in an Oracle database. To load data from external files into an Oracle database, two types of input must be provided to SQL*Loader : the data itself and the control file. The control file describes the data to be loaded. It describes the Names and format of the data files, Specifications for loading data and the Data to be loaded (optional). Invoking the loader sqlload username/password controlfilename <options>.