As such, we've defined it with a simple foreign key in the orders table pointing to a given customer_id, and we can use JOIN clauses in our SELECT queries fairly easily. Many-to-many relationships are a bit more complicated. For example, what if we had an orders table and a ...
SQL is Structured Query Language designed for inserting and modifying in a relational database management system. 11.What are the differences between DDL, DML and DCL in SQL? Ans: Following are some details of three. DDL stands for Data Definition Language. SQL queries like CREATE, ALTER, DROP...
name given to a table or column which do not exist once the SQL statement is executed. Q. What is a view ? A view is a virtual table based on one or more tables. Why Use views ? To restrict data access • To make complex queries easy ...
If you want to understand the foundational concepts of the Oracle database, I recommend taking ourIntroduction to Oracle SQLcourse, which is a really important resource to learn how to interact with the Oracle database and how the database uses PL/SQL to process queries. Beginner PL/SQL Inte...
More acceptances towards the queries Accessing information fast Easy implementation of security measures Ensures flexibility in modifications Eradicating unreal data and decreasing the redundancy Compact database storage Maintaining data consistency This is one of the most crucialSQL Interview questionswhich can...
5. What are the user roles available in SSRS? 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 ...
SQL queries with basic group by self joins and inner queries. The problem could be solved by analytical queries. SQL and why is the number of likes increasing? There’s a game where you are given two fair six-sided dice and asked to roll. If the sum of the values on the dice equals...
subqueries the inner queries are executed first and then the outer query is executed but in Correlated Subquery outer query is always dependent on inner query so first outer query is executed then inner query is executed.Correlated Subqueries always uses operator like Exist,Not Exist,IN,Not IN.Co...
SQL Server Agent: Tool for scheduling and automating database tasks. Indexes: Technique for improving the performance of database queries. Stored Procedures: Predefined SQL queries are stored in the database for quick execution. Views: Virtual tables representing the result of a SQL query, simplifyi...
It allows the PostgreSQL search query optimizer to support large joined queries in an effective manner using a non-exhaustive search technique. Q44. How many byte Unique integers does OIDs in PostgreSQL? Answer In PostgreSQL, there are 4 bytes of unique integers by default....