SQL Advanced level for Analysts

There are no specific requirements needed to attend this course.

The aim of this course is to provide a clear understanding of the use of SQL for different
databases (Oracle, SQL Server, MS Access...). Understanding of analytic functions and the
way how to join different tables in a database will help delegates to move data analysis
operations to the database side, instead of doing this in MS Excel application. This can also
help in creating any IT system, which uses any relational database.

Selecting data from database

• Syntax rules
• Selecting all columns
• Projection
• Arithmetical operations in SQL
• Columns aliases
• Literals
• Concatenation

Filtering outcome tables

• WHERE clause
• Comparison operators
• Condition LIKE
• Condition BETWEEN...AND
• Condition IS NULL
• Condition IN
• AND, OR, NOT operators
• Several conditions in WHERE clause
• Operators order
• DISTINCT clause

Sorting outcome tables

• ORDER BY clause
• Sort by multiple columns or expressions

SQL Functions

• Differences between single-row and multi-row functions
• Character, numeric, DateTime functions
• Explicit and implicit conversion
• Conversion functions
• Nested functions
• Dual table (Oracle vs other databases)
• Getting current date and time with different functions

Aggregate data using aggregate functions

• Aggregate functions
• Aggregate functions vs NULL value
• GROUP BY clause
• Grouping using different columns
• Filtering aggregated data - HAVING clause
• Multidimensional Data Grouping - ROLLUP and CUBE operators
• Identifying summaries - GROUPING
• GROUPING SETS operator

Retrieving data from multiple tables

• Different types of joints
• NATURAL JOIN
• Table aliases
• Oracle syntax - join conditions in WHERE clause
• SQL99 syntax - INNER JOIN
• SQL99 syntax - LEFT, RIGHT, FULL OUTER JOINS
• Cartesian product - Oracle and SQL99 syntax

subqueries

• When and where subquery can be done
• Single-row and multi-row subqueries
• Single-row subquery operators
• Aggregate functions in subqueries
• Multi-row subquery operators - IN, ALL, ANY

Set operators

• UNION
• UNION ALL
• INTERSECT
• MINUS/EXCEPT

Transactions

• COMMIT, ROLLBACK SAVEPOINT statements

Other schema objects

• Sequences
• Synonyms
• Views

Hierarchical queries and samples

• Tree construction (CONNECT BY PRIOR and START WITH clauses)
• SYS_CONNECT_BY_PATH function

Conditional expressions

• CASE expression
• DECODE expression

Data management in different time zones

• Time zones
• TIMESTAMP data types
• Differences between DATE and TIMESTAMP
• Conversion operations

Analytic functions

• Use of
• Partitions
• Windows
• Rank functions
• Reporting functions
• LAG/LEAD functions
• FIRST/LAST functions
• Reverse percentile functions
• hypothetical rank functions
• WIDTH_BUCKET functions
• Statistical functions