SQL Syntax

Subquery

A subquery is a query nested inside another SQL query, often used to retrieve data that will be used in the main query's condition.

test

this is the answer

testee

tjhis is the answer

Obtains a portion of a string.

What does SUBSTR() do?

r

What would SUBSTR(‘Trevor, -1) return?

Replace a portion of or a whole string. Ex: REPLACE(names, ‘Matt’, ‘Matthew’)

REPLACE() is used to do what?

Last name of customers with last name ending in a, r, or s.

What would this query return?

The year, quarter, month, week, day from a column with the DATE data type.

What does EXTRACT() allow us to return?

clause used to combine and retrieve records from two or multiple tables.

JOIN

collection of database structural elements such as tables, stored procedures, indexes, functions, and triggers.

Schema

joins two or more string values appending the second string to the end of the first one

CONCAT()

creates a special data structure that speeds up data retrieval by allowing the database to find rows more efficiently.

Indexing

way to implement the if-then-else logic in SQL.

CASE Statement

captures, stores, and processes data from transactions in real time.

OLTP

OLTP

captures, stores, and processes data from transactions in real time.