From 80120a62b3d9d89b0cc733ae3cc5c6fac550f166 Mon Sep 17 00:00:00 2001
From: ThomasCode92 <thomascode92@hotmail.com>
Date: Tue, 24 Oct 2023 21:02:42 +0200
Subject: [PATCH 01/13] The Module Project

---
 .vscode/settings.json                   |  4 ++--
 data/create-data/01-create-database.sql |  1 +
 data/create-data/02-create-table.sql    | 14 ++++++++++++++
 data/create-data/03-add-table-data.sql  |  8 ++++++++
 4 files changed, 25 insertions(+), 2 deletions(-)
 create mode 100644 data/create-data/01-create-database.sql
 create mode 100644 data/create-data/02-create-table.sql
 create mode 100644 data/create-data/03-add-table-data.sql

diff --git a/.vscode/settings.json b/.vscode/settings.json
index 375aedb..62fdbf9 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -26,7 +26,7 @@
       "port": 3306,
       "driver": "MySQL",
       "name": "mysql",
-      "database": "default",
+      "database": "gym",
       "username": "root",
       "askForPassword": true
     },
@@ -36,7 +36,7 @@
       "port": 5432,
       "driver": "PostgreSQL",
       "name": "postgresql",
-      "database": "default",
+      "database": "gym",
       "username": "postgres",
       "askForPassword": true
     }
diff --git a/data/create-data/01-create-database.sql b/data/create-data/01-create-database.sql
new file mode 100644
index 0000000..378eb9d
--- /dev/null
+++ b/data/create-data/01-create-database.sql
@@ -0,0 +1 @@
+CREATE DATABASE gym;
diff --git a/data/create-data/02-create-table.sql b/data/create-data/02-create-table.sql
new file mode 100644
index 0000000..a389487
--- /dev/null
+++ b/data/create-data/02-create-table.sql
@@ -0,0 +1,14 @@
+CREATE TABLE memberships (
+    id INT PRIMARY KEY AUTO_INCREMENT, -- MySQL syntax
+    -- id SERIAL PRIMARY KEY, --PostgreSQL syntax
+    membership_start DATE,
+    membership_end DATE,
+    last_checkin TIMESTAMP,
+    last_checkout TIMESTAMP,
+    consumption NUMERIC(5, 2),
+    first_name VARCHAR(200),
+    last_name VARCHAR(200),
+    price NUMERIC(5, 2),
+    billing_frequency INT,
+    gender VARCHAR(200)
+);
diff --git a/data/create-data/03-add-table-data.sql b/data/create-data/03-add-table-data.sql
new file mode 100644
index 0000000..724409d
--- /dev/null
+++ b/data/create-data/03-add-table-data.sql
@@ -0,0 +1,8 @@
+INSERT INTO memberships (
+  membership_start, membership_end, last_checkin, last_checkout,
+  consumption, first_name, last_name, price, billing_frequency, gender
+)
+VALUES
+  ('2021-10-01', NULL, '2021-10-01 05:17:36', '2021-10-01 06:20:45', 26.49, 'Max', 'Schwarz', 19.99, 12, 'male'),
+  ('2020-05-10', '2022-05-09', '2021-11-03 10:01:56', '2021-11-03 14:30:00', 100.26, 'Manu', 'Lorenz', 199.99, 1, 'male'),
+  ('2021-02-18', '2022-02-17', '2021-10-29 15:26:05', '2021-10-29 17:01:33', 5.10, 'Julie', 'Barnes', 199.99, 1, 'female');

From 3609d9550fbedc944189d19c4fdb1ebdd8567af8 Mon Sep 17 00:00:00 2001
From: ThomasCode92 <thomascode92@hotmail.com>
Date: Tue, 24 Oct 2023 21:02:47 +0200
Subject: [PATCH 02/13] Working with Mathematical Functions & Arithmetic
 Operators

---
 data/01-mathematical-functions.sql | 10 ++++++++++
 1 file changed, 10 insertions(+)
 create mode 100644 data/01-mathematical-functions.sql

diff --git a/data/01-mathematical-functions.sql b/data/01-mathematical-functions.sql
new file mode 100644
index 0000000..a18f98e
--- /dev/null
+++ b/data/01-mathematical-functions.sql
@@ -0,0 +1,10 @@
+SELECT price * billing_frequency AS annual_revenue
+FROM memberships;
+
+-- CEIL()
+-- FLOOR()
+-- ROUND()
+-- TRUNC() TRUNCATE() mysql
+
+SELECT TRUNC(consumption, 0) 
+FROM memberships;

From c6bd5579ad91d298d98a0de8ca3794c61345fc4a Mon Sep 17 00:00:00 2001
From: ThomasCode92 <thomascode92@hotmail.com>
Date: Thu, 26 Oct 2023 19:34:15 +0200
Subject: [PATCH 03/13] Understanding String Functions with SELECT

---
 data/02-string-functions.sql | 5 +++++
 1 file changed, 5 insertions(+)
 create mode 100644 data/02-string-functions.sql

diff --git a/data/02-string-functions.sql b/data/02-string-functions.sql
new file mode 100644
index 0000000..d87032d
--- /dev/null
+++ b/data/02-string-functions.sql
@@ -0,0 +1,5 @@
+SELECT CONCAT(first_name, ' ', last_name)
+FROM memberships;
+
+SELECT CONCAT('$ ', price)
+FROM memberships;

From 0591d8f4f87a0a5ede1e95eea910c1a8136c26e7 Mon Sep 17 00:00:00 2001
From: ThomasCode92 <thomascode92@hotmail.com>
Date: Thu, 26 Oct 2023 19:34:26 +0200
Subject: [PATCH 04/13] Using String Functions with INSERT

---
 data/02-string-functions.sql | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/data/02-string-functions.sql b/data/02-string-functions.sql
index d87032d..62fbcef 100644
--- a/data/02-string-functions.sql
+++ b/data/02-string-functions.sql
@@ -3,3 +3,23 @@ FROM memberships;
 
 SELECT CONCAT('$ ', price)
 FROM memberships;
+
+INSERT INTO memberships (
+  membership_start, membership_end, last_checkin, last_checkout,
+  consumption, first_name, last_name, price, billing_frequency, gender)
+VALUES (
+  '2021-10-18', '2021-11-18', '2021-11-01 08:56:01', '2021-11-01 09:20:12',
+  NULL, 'John', 'Doe', 19.99, 12, LOWER('DivErs'));
+
+SELECT * FROM memberships
+WHERE LENGTH(last_name) < 7;
+
+INSERT INTO memberships (
+    membership_start, membership_end, last_checkin, last_checkout,
+  consumption, first_name, last_name, price, billing_frequency, gender)
+VALUES (
+  '2021-05-02', NULL, '2021-06-05 11:52:25', '2021-06-05 11:58:08',
+  NULL, 'Monti', 'Durns', 199.99, 1, TRIM(TRAILING ' ' FROM 'male  ')
+);
+
+SELECT LENGTH(gender) FROM memberships;

From f1738e01cc97b0984d8313744db0e37306bb4931 Mon Sep 17 00:00:00 2001
From: ThomasCode92 <thomascode92@hotmail.com>
Date: Thu, 26 Oct 2023 19:35:09 +0200
Subject: [PATCH 05/13] Understanding Date/ Time Functions

---
 data/03-date-time-functions.sql | 2 ++
 1 file changed, 2 insertions(+)
 create mode 100644 data/03-date-time-functions.sql

diff --git a/data/03-date-time-functions.sql b/data/03-date-time-functions.sql
new file mode 100644
index 0000000..5c1dc0f
--- /dev/null
+++ b/data/03-date-time-functions.sql
@@ -0,0 +1,2 @@
+SELECT EXTRACT(MINUTE FROM last_checkin), last_checkin
+FROM memberships;

From 58a098372385bfb617930dc3cad0d990bdf9f539 Mon Sep 17 00:00:00 2001
From: ThomasCode92 <thomascode92@hotmail.com>
Date: Sat, 28 Oct 2023 15:09:25 +0200
Subject: [PATCH 06/13] Working with Weekdays

---
 data/03-date-time-functions.sql | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/data/03-date-time-functions.sql b/data/03-date-time-functions.sql
index 5c1dc0f..e773548 100644
--- a/data/03-date-time-functions.sql
+++ b/data/03-date-time-functions.sql
@@ -1,2 +1,18 @@
 SELECT EXTRACT(MINUTE FROM last_checkin), last_checkin
 FROM memberships;
+
+-- MySQL syntax
+SELECT WEEKDAY(last_checkin) + 1, last_checkin 
+FROM memberships;
+
+-- PostgreSQL syntax
+SELECT EXTRACT(ISODOW FROM last_checkin), last_checkin 
+FROM memberships;
+
+-- MySQL syntax
+SELECT CONVERT(last_checkin, DATE), CONVERT(last_checkin, TIME)
+FROM memberships;
+
+-- PostgreSQL syntax
+SELECT last_checkin::TIMESTAMP::DATE, last_checkin::TIMESTAMP::TIME
+FROM memberships;

From 2b96707244993739361fb4e939b77f86d4e6adfd Mon Sep 17 00:00:00 2001
From: ThomasCode92 <thomascode92@hotmail.com>
Date: Sat, 28 Oct 2023 15:14:16 +0200
Subject: [PATCH 07/13] Calculating INTERVALS

---
 data/04-date-time-differences.sql | 11 +++++++++++
 1 file changed, 11 insertions(+)
 create mode 100644 data/04-date-time-differences.sql

diff --git a/data/04-date-time-differences.sql b/data/04-date-time-differences.sql
new file mode 100644
index 0000000..f94cddb
--- /dev/null
+++ b/data/04-date-time-differences.sql
@@ -0,0 +1,11 @@
+-- MySQL syntax
+SELECT TIMESTAMPDIFF(MINUTE, last_checkin, last_checkout)
+FROM memberships;
+
+-- MySQL syntax
+SELECT DATEDIFF(NOW(), membership_start)
+FROM memberships;
+
+-- PostgreSQL syntax
+SELECT NOW() - membership_start
+FROM memberships;

From bd492144e7d1491acffffef9f5985f403894a671 Mon Sep 17 00:00:00 2001
From: ThomasCode92 <thomascode92@hotmail.com>
Date: Sat, 28 Oct 2023 15:17:38 +0200
Subject: [PATCH 08/13] Adding INTERVALS to Dates

---
 data/05-changing-dates.sql | 11 +++++++++++
 1 file changed, 11 insertions(+)
 create mode 100644 data/05-changing-dates.sql

diff --git a/data/05-changing-dates.sql b/data/05-changing-dates.sql
new file mode 100644
index 0000000..3fd03d6
--- /dev/null
+++ b/data/05-changing-dates.sql
@@ -0,0 +1,11 @@
+-- PostgreSQL syntax
+SELECT membership_start + 7, membership_start
+FROM memberships;
+
+-- MySQL syntax
+SELECT DATE_ADD(membership_start, INTERVAL 7 DAY), membership_start
+FROM memberships;
+
+-- PostgreSQL syntax
+SELECT (membership_start + INTERVAL '7 DAY')::TIMESTAMP::DATE, membership_start
+FROM memberships;

From ce3bdd9dc102a25c5f8306f51404b5c130550a4d Mon Sep 17 00:00:00 2001
From: ThomasCode92 <thomascode92@hotmail.com>
Date: Sat, 28 Oct 2023 15:18:56 +0200
Subject: [PATCH 09/13] Understanding LIKE & Pattern Matching

---
 data/06-like-pattern-matching.sql | 9 +++++++++
 1 file changed, 9 insertions(+)
 create mode 100644 data/06-like-pattern-matching.sql

diff --git a/data/06-like-pattern-matching.sql b/data/06-like-pattern-matching.sql
new file mode 100644
index 0000000..cf49201
--- /dev/null
+++ b/data/06-like-pattern-matching.sql
@@ -0,0 +1,9 @@
+SELECT first_name LIKE '__o%', first_name
+FROM memberships;
+
+SELECT first_name LIKE 'Ma%', first_name
+FROM memberships;
+
+SELECT first_name
+FROM memberships
+WHERE first_name LIKE 'J____';

From b43b66c40f23e869b11ded0fb1f8b413c27f9977 Mon Sep 17 00:00:00 2001
From: ThomasCode92 <thomascode92@hotmail.com>
Date: Sat, 28 Oct 2023 15:25:59 +0200
Subject: [PATCH 10/13] Understanding EXISTS

---
 data/07-exists-subquery-expressions.sql          |  9 +++++++++
 data/create-data/04-create-additional-tables.sql | 14 ++++++++++++++
 data/create-data/05-insert-additional-data.sql   |  8 ++++++++
 3 files changed, 31 insertions(+)
 create mode 100644 data/07-exists-subquery-expressions.sql
 create mode 100644 data/create-data/04-create-additional-tables.sql
 create mode 100644 data/create-data/05-insert-additional-data.sql

diff --git a/data/07-exists-subquery-expressions.sql b/data/07-exists-subquery-expressions.sql
new file mode 100644
index 0000000..5c9407c
--- /dev/null
+++ b/data/07-exists-subquery-expressions.sql
@@ -0,0 +1,9 @@
+SELECT first_name, last_name
+FROM customers
+WHERE email = 'max@test.com';
+
+SELECT EXISTS(
+  SELECT first_name, last_name
+  FROM customers
+  WHERE email = 'manu@test.com'
+);
diff --git a/data/create-data/04-create-additional-tables.sql b/data/create-data/04-create-additional-tables.sql
new file mode 100644
index 0000000..9d198f9
--- /dev/null
+++ b/data/create-data/04-create-additional-tables.sql
@@ -0,0 +1,14 @@
+CREATE TABLE customers(
+  id INT PRIMARY KEY AUTO_INCREMENT, -- MySQL syntax
+  -- id SERIAL PRIMARY KEY, --PostgreSQL syntax
+  first_name VARCHAR(200),
+  last_name VARCHAR(200),
+  email VARCHAR(200)
+);
+
+CREATE TABLE orders(
+  id INT PRIMARY KEY AUTO_INCREMENT, -- MySQL syntax
+  -- id SERIAL PRIMARY KEY, --PostgreSQL syntax
+  amount_billed NUMERIC(5, 2),
+  customer_id INT REFERENCES customers
+);
\ No newline at end of file
diff --git a/data/create-data/05-insert-additional-data.sql b/data/create-data/05-insert-additional-data.sql
new file mode 100644
index 0000000..7f8363e
--- /dev/null
+++ b/data/create-data/05-insert-additional-data.sql
@@ -0,0 +1,8 @@
+INSERT INTO customers(first_name, last_name, email)
+VALUES
+  ('Max', 'Schwarz', 'max@test.com'),
+  ('Manu', 'Lorenz', 'manu@test.com'),
+  ('Julia', 'Meyers', 'juli@test.com');
+
+INSERT INTO orders(amount_billed, customer_id)
+VALUES (48.99,1), (27.45, 2), (19.49, 1), (8.49, 3);

From 7e44df6319f4826c8d7c2aeb436b6e34ab31c142 Mon Sep 17 00:00:00 2001
From: ThomasCode92 <thomascode92@hotmail.com>
Date: Sat, 28 Oct 2023 15:26:09 +0200
Subject: [PATCH 11/13] Working with Subquery Expressions and EXISTS

---
 data/07-exists-subquery-expressions.sql | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/data/07-exists-subquery-expressions.sql b/data/07-exists-subquery-expressions.sql
index 5c9407c..f7ea05c 100644
--- a/data/07-exists-subquery-expressions.sql
+++ b/data/07-exists-subquery-expressions.sql
@@ -7,3 +7,11 @@ SELECT EXISTS(
   FROM customers
   WHERE email = 'manu@test.com'
 );
+
+SELECT o.id
+FROM orders AS o
+WHERE EXISTS(
+  SELECT c.email
+  FROM customers as c
+  WHERE o.customer_id = c.id AND c.email = 'max@test.com'
+);

From d57331a2078bc88b8b8bc742f0d298ff0d029d0a Mon Sep 17 00:00:00 2001
From: ThomasCode92 <thomascode92@hotmail.com>
Date: Sat, 28 Oct 2023 15:29:59 +0200
Subject: [PATCH 12/13] Working with Subquery Expressions and IN

---
 data/08-in-subquery-expressions.sql  | 19 +++++++++++++++++++
 data/create-data/06-add-customer.sql |  2 ++
 2 files changed, 21 insertions(+)
 create mode 100644 data/08-in-subquery-expressions.sql
 create mode 100644 data/create-data/06-add-customer.sql

diff --git a/data/08-in-subquery-expressions.sql b/data/08-in-subquery-expressions.sql
new file mode 100644
index 0000000..5fda70a
--- /dev/null
+++ b/data/08-in-subquery-expressions.sql
@@ -0,0 +1,19 @@
+SELECT email FROM customers;
+
+SELECT c.email FROM customers AS c
+INNER JOIN orders AS o ON c.id = o.customer_id;
+
+SELECT id
+FROM customers
+WHERE first_name = 'Max' OR first_name = 'Manu';
+
+SELECT id, first_name
+FROM customers
+WHERE first_name IN('Max', 'Manu');
+
+SELECT email
+FROM customers
+WHERE id IN(
+    SELECT customer_id
+    FROM orders
+);
diff --git a/data/create-data/06-add-customer.sql b/data/create-data/06-add-customer.sql
new file mode 100644
index 0000000..b6a0e58
--- /dev/null
+++ b/data/create-data/06-add-customer.sql
@@ -0,0 +1,2 @@
+INSERT INTO customers(first_name, last_name, email)
+VALUES('Ken', 'Brooks', 'ken@test.com');

From 77cb5cd4613874fe5e4584cb051f0262634d20d8 Mon Sep 17 00:00:00 2001
From: ThomasCode92 <thomascode92@hotmail.com>
Date: Sat, 28 Oct 2023 15:33:14 +0200
Subject: [PATCH 13/13]  Introducing Conditional Expressions

---
 data/09-conditional-expressions.sql | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)
 create mode 100644 data/09-conditional-expressions.sql

diff --git a/data/09-conditional-expressions.sql b/data/09-conditional-expressions.sql
new file mode 100644
index 0000000..3cf625e
--- /dev/null
+++ b/data/09-conditional-expressions.sql
@@ -0,0 +1,21 @@
+SELECT amount_billed,
+  CASE WHEN amount_billed > 15 AND amount_billed <= 30 THEN 'Normal Day'
+    WHEN amount_billed > 30 THEN 'Good Day'
+    ELSE 'Bad Day'
+  END
+FROM orders;
+
+-- MySQL syntax
+SELECT weekday_nr,
+  CASE WHEN weekday_nr = 1 THEN 'Monday'
+    WHEN weekday_nr = 2 THEN 'Tuesday'
+    WHEN weekday_nr = 3 THEN 'Wednesday'
+    WHEN weekday_nr = 4 THEN 'Thursday'
+    WHEN weekday_nr = 5 THEN 'Friday'
+    WHEN weekday_nr = 6 THEN 'Saturday'
+    ELSE 'Sunday'
+  END
+FROM (
+  SELECT WEEKDAY(last_checkin) + 1 AS weekday_nr
+  FROM memberships
+) AS weekday_numbers;