SQL Used Directly in Practice [Lecture by the author of '200 SQL Examples']

Data has become more closely connected to our daily lives than ever before.
And SQL is being used as one of the programming skills to think about various social phenomena
and find answers.

SQL has the power to make you ask questions and think.
As you search through data in various ways, you sometimes find answers you never even thought of.

Those questions can be of many kinds.
They could be about current social phenomena or predicting the future.

While this course teaches you SQL,
it also teaches you how to directly find, collect, and extract information from data.

We find these things through data.

All data is stored and managed in databases.
SQL is a very powerful language for finding information in a database.

Oracle has built-in technology to process large amounts of data quickly.
And as versions are upgraded, optimizing technology continues to advance.
Users can also easily implement machine learning with simple SQL.

The SQL course is structured from the basics to a level that can be applied in practice.
I sincerely hope this will be helpful to many people studying SQL.

Questions and Feedback

Feel free to ask questions and provide feedback on the SQL lectures at Instructor Yeonsu Yoo's cafe,
and improve your skills by checking out other people's queries!

A lecture taught directly by the author of the book "SQL 200 Exercises," published by Infomunhwasa!

Over the years, numerous data analysts have empowered their data retrieval skills through instructor Yu Yeon-su's SQL lectures.

Ranked #1 in student recommendations! The very course chosen by 2,000 people! This SQL course is now available on Inflearn.

Employment status of non-major students in the field of data analysis

Here is the employment and career transition status of those who have taken Instructor Yeon-su Yu's SQL course.

If you want to get a job as a data analyst, take this course right away.

Curriculum

PART 1 〈Introductory〉 Taking Your First Steps in SQL
001 Selecting Specific Columns from a Table
002 Displaying All Columns from a Table
003 Changing Displayed Column Names Using Column Aliases
004 Using the Concatenation Operator (||)
005 Displaying Data with Duplicates Removed (DISTINCT)
006 Sorting and Displaying Data (ORDER BY)
007 Learning the WHERE Clause ① (Searching Numeric Data)
008 Learning the WHERE Clause ② (Searching Characters and Dates)
009 Learning Arithmetic Operators (*, /, +, -)
010 Learning Comparison Operators ① (〉, 〈, 〉=, 〈=, =, !=, 〈〉, ^=)
011 Learning Comparison Operators ② (BETWEEN AND)
012 Learning Comparison Operators ③ (LIKE)
013 Learning Comparison Operators ④ (IS NULL)
014 Learning Comparison Operators ⑤ (IN)
015 Learning Logical Operators (AND, OR, NOT)

PART 2 〈Beginner〉 Strengthening SQL Foundations
016 Learning Case Conversion Functions (UPPER, LOWER, INITCAP)
017 Extracting Specific Characters from Text (SUBSTR)
018 Displaying the Length of a String (LENGTH)
019 Displaying the Position of Specific Characters in Text (INSTR)
020 Replacing Specific Characters with Other Characters (REPLACE)
021 Padding Specific Characters N Times (LPAD, RPAD)
022 Trimming Specific Characters (TRIM, RTRIM, LTRIM)
023 Displaying Rounded Values (ROUND)
024 Displaying Values by Truncating Numbers (TRUNC)
025 Displaying the Remainder of a Division (MOD)
026 Displaying the Number of Months Between Dates (MONTHS_BETWEEN)
027 Displaying a Date After Adding Months (ADD_MONTHS)
028 Displaying the Date of a Specific Weekday Following a Certain Date (NEXT_DAY)
029 Displaying the Last Date of the Month for a Specific Date (LAST_DAY)
030 Converting Data Types to Character Type (TO_CHAR)
031 Converting Data Types to Date Type (TO_DATE)
032 Understanding Implicit Type Conversion
033 Displaying Alternative Data Instead of NULL Values (NVL, NVL2)
034 Implementing IF Statements in SQL ① (DECODE)
035 Implementing IF Statements in SQL ② (CASE)
036 Displaying the Maximum Value (MAX)
037 Displaying the Minimum Value (MIN)
038 Displaying the Average Value (AVG)
039 Displaying the Total Value (SUM)
040 Displaying the Count (COUNT)
041 Displaying Rankings with Data Analysis Functions ① (RANK)
042 Displaying Rankings with Data Analysis Functions ② (DENSE_RANK)
043 Displaying Grades with Data Analysis Functions (NTILE)
044 Displaying the Ratio of Rankings with Data Analysis Functions (CUME_DIST)
045 Displaying Data Horizontally with Data Analysis Functions (LISTAGG)
046 Displaying the Previous and Next Rows with Data Analysis Functions (LAG, LEAD)
047 Displaying COLUMNS as ROWS ① (SUM+DECODE)
048 Displaying COLUMNS as ROWS ② (PIVOT)
049 Displaying ROWS as COLUMNS (UNPIVOT)
050 Displaying Cumulative Data with Data Analysis Functions (SUM OVER)
051 Displaying Ratios with Data Analysis Functions (RATIO_TO_REPORT)
052 Displaying Aggregate Results with Data Analysis Functions ① (ROLLUP)
053 Displaying Aggregate Results with Data Analysis Functions ② (CUBE)
054 Displaying Aggregate Results with Data Analysis Functions ③ (GROUPING SETS)
055 Numbering Output Results with Data Analysis Functions (ROW_NUMBER)

PART 3 〈Intermediate〉 Enhancing SQL Skills
056 Limiting Displayed Rows ① (ROWNUM)
057 Limiting Displayed Rows ② (Simple TOP-n Queries)
058 Joining and Displaying Data from Multiple Tables ① (EQUI JOIN)
059 Joining and Displaying Data from Multiple Tables ② (NON EQUI JOIN)
060 Joining and Displaying Data from Multiple Tables ③ (OUTER JOIN)
061 Joining and Displaying Data from Multiple Tables ④ (SELF JOIN)
062 Joining and Displaying Data from Multiple Tables ⑤ (ON Clause)
063 Joining and Displaying Data from Multiple Tables ⑤ (USING Clause)
064 Joining and Displaying Data from Multiple Tables ⑥ (NATURAL JOIN)
065 Joining and Displaying Data from Multiple Tables ⑦ (LEFT/RIGHT OUTER JOIN)
066 Joining and Displaying Data from Multiple Tables ⑧ (FULL OUTER JOIN)
067 Connecting Data Vertically with Set Operators ① (UNION ALL)
068 Connecting Data Vertically with Set Operators ② (UNION)
069 Displaying the Intersection of Data with Set Operators (INTERSECT)
070 Displaying the Difference of Data with Set Operators (MINUS)
071 Using Subqueries ① (Single-Row Subquery)
072 Using Subqueries ② (Multi-Row Subquery)
073 Using Subqueries ③ (NOT IN)
074 Using Subqueries ④ (EXISTS and NOT EXISTS)
075 Using Subqueries ⑤ (Subquery in HAVING Clause)
076 Using Subqueries ⑥ (Subquery in FROM Clause)
077 Using Subqueries ⑦ (Subquery in SELECT Clause)
078 Inserting Data (INSERT)
079 Updating Data (UPDATE)
080 Deleting Data (DELETE, TRUNCATE, DROP)
081 Saving and Canceling Data (COMMIT, ROLLBACK)
082 Inserting, Updating, and Deleting Data All at Once (MERGE)
083 Understanding Locks (LOCK)
084 Understanding the SELECT FOR UPDATE Clause
085 Inserting Data Using Subqueries
086 Updating Data Using Subqueries
087 Deleting Data Using Subqueries
088 Merging Data Using Subqueries
089 Displaying Data with Hierarchy Using Hierarchical Queries ①
090 Displaying Data with Hierarchy Using Hierarchical Queries ②
091 Displaying Data with Hierarchy Using Hierarchical Queries ③
092 Displaying Data with Hierarchy Using Hierarchical Queries ④
093 Creating a Standard Table (CREATE TABLE)
094 Creating a Temporary Table (CREATE TEMPORARY TABLE)
095 Simplifying Complex Queries ① (VIEW)
096 Simplifying Complex Queries ② (VIEW)
097 Increasing Data Search Speed (INDEX)
098 Creating Numbers That Never Duplicate (SEQUENCE)
099 Recovering Accidentally Deleted Data ① (FLASHBACK QUERY)
100 Recovering Accidentally Deleted Data ② (FLASHBACK TABLE)
101 Recovering Accidentally Deleted Data ③ (FLASHBACK DROP)
102 Recovering Accidentally Deleted Data ④ (FLASHBACK VERSION QUERY)
103 Recovering Accidentally Deleted Data ⑤ (FLASHBACK TRANSACTION QUERY)
104 Improving Data Quality ① (PRIMARY KEY)
105 Improving Data Quality ② (UNIQUE)
106 Improving Data Quality ③ (NOT NULL)
107 Improving Data Quality ④ (CHECK)
108 Improving Data Quality ⑤ (FOREIGN KEY)
109 Using the WITH Clause ① (WITH ~ AS)
110 Using the WITH Clause ② (SUBQUERY FACTORING)
111 Solving Algorithm Problems with SQL ① (Displaying the 2 Times Table)
112 Solving Algorithm Problems with SQL ② (Displaying Multiplication Tables 1 to 9)
113 Solving Algorithm Problems with SQL ③ (Displaying a Right Triangle)
114 Solving Algorithm Problems with SQL ④ (Displaying a Triangle)
115 Solving Algorithm Problems with SQL ⑤ (Displaying a Diamond)
116 Solving Algorithm Problems with SQL ⑥ (Displaying a Square)
117 Solving Algorithm Problems with SQL ⑦ (Sum of Numbers from 1 to 10)
118 Solving Algorithm Problems with SQL ⑧ (Product of Numbers from 1 to 10)
119 Solving Algorithm Problems with SQL ⑨ (Displaying Only Even Numbers from 1 to 10)
120 Solving Algorithm Problems with SQL ⑩ (Displaying Only Prime Numbers from 1 to 10)
121 Solving Algorithm Problems with SQL ⑪ (Greatest Common Divisor)
122 Solving Algorithm Problems with SQL ⑫ (Least Common Multiple)
123 Solving Algorithm Problems with SQL ⑬ (Pythagorean Theorem)
124 Solving Algorithm Problems with SQL ⑭ (Monte Carlo Algorithm)
125 Solving Algorithm Problems with SQL ⑮ (Finding Euler's Constant / Natural Constant)

PART 4 〈Application〉 Mastering SQL Applications
126 How to Load Excel Data into a DB
127 What is the most frequent word in Steve Jobs' speech?
128 Are there more positive or negative words in Steve Jobs' speech?
129 On which day of the week does theft occur most frequently?
130 Which school has the highest college tuition in Korea?
131 What are the most expensive items and their prices among Seoul's cost of living?
132 Where do murders occur most frequently?
133 What is the most common type of crime resulting from family discord?
134 What is the biggest cause of arson incidents?
135 Which region in the country has the highest number of traffic accidents?
136 In which year were there the most chicken shop closures?
137 Which country in the world has the longest working hours?
138 What are the most common types of cancer for men and women respectively?

You need to master SQL through the following four levels of skills. This course covers Level 1 among them.