You can sign up to the Udacity free course here
Udacity offer a great free SQL course designed to take complete beginners to confident analysts in just 4 weeks. The course is a self paced online course comprised of a series of tutor-led videos, interactive activities and downloadable resources. We recommend you complete the first 3 modules for a basic understanding before you start using Ravelin’s DWH. The time estimates below are conservative; fast learners will do this much quicker!
The course will cover the following topics:
Basic SQL - 4 hrs
Gain basic SQL knowledge and learn to structure a query and filter data from a single table. You’ll also get comfortable with statements such as WHERE, LIKE, IN, BETWEEN and AND.
SQL Joins - 5 hrs
Learn to bring data from multiple tables together and the different types of joins you can use.
SQL Aggregations - 6 hrs
Aggregate data with basic commands such as SUM, AVG and COUNT.
SQL Subqueries and temporary tables - 5 hrs
Answer more complex business questions using nested querying methods
SQL Data Cleaning - 5 hrs
Fix incorrect, incomplete, duplicate or otherwise erroneous data in the data set.
Advanced SQL Window Functions - 3 hrs
Compare one row to another without joins using powerful SQL concepts
Advanced SQL JOINs and Performance Tuning - 3 hrs
Advanced joins and how to make queries run quickly across giant datasets.
SELECT Select data from database
FROM Specify the table you are pulling from
WHERE Filter query to match a condition
AS Rename column or table with alias
JOIN Combine rows from two or more tables
AND Combine query conditions (all must be met)
OR Combine query conditions (one must be met)
LIMIT Limit rows returned (See also FETCH and TOP)
IN Specify multiple values when using where
CASE Return value on a specified condition
IS NULL Return only rows with a NULL value
LIKE Search for patterns in column
COMMIT Write transaction to database
ROLLBACK Undo a transaction block
ALTER TABLE Add/Remove columns from table
UPDATE Update table data
CREATE Create TABLE, DATABASE, INDEX or VIEW
DELETE Delete rows from table
INSERT Add single row to table
DROP Delete TABLE, DATABASE, or INDEX
GROUP BY Group data into logical sets
ORDER BY Set order of results - ASC or DESC
HAVING Same as WHERE but filters groups
COUNT Count number of rows
SUM Return sum of column
AVG Return average of column
MIN Return min value of column
MAX Return max value of column
| % | Zero or more characters | bl% finds bl, black, blue, and blob |
|---|---|---|
| _ | A single character | h_t finds hot, hat, and hit |
| [] | Any single character within the brackets | h[oa]t finds hot and hat, but not hit |
| ^ | Any character not in the brackets | h[^oa]t finds hit, but not hot and hat |
| - | Any single character within the specified range | c[a-b]t finds cat and cbt |