Thread by @orc_arn

1⃣ Today, I'll continue with Chapter II. This chapter focuses on data types and creating / populating data.

Since I was aware of the data types, I try to summarize the chapter. For who are new to #SQL should read in detail.

For statistics related treads, see @levikul09.

https://twitter.com/orc_arn/status/1530894610817499136

2⃣ #MySQL Datatypes
1. Character data:
☑️ Fixed-length : right-pinned with spaces
☑️ Variable length : not padded, space consumption varies
i.e : char(20) - fixed ; varchar(20) variable length examples.

3⃣ Character Sets are used for different languages with different letters
Returns a table with different char sets. If maxlen bigger than 1, the chars in that language are bigger than 1 bytes.

4⃣ Text Data

There are 4 types of text data in #MySQL
tinytext
text
mediumtext
longtext

Which are ordered by the characters they can store. After #MySQL v.4 varchar can store 64 KB, so tinytext and text are not necessary.
Medium-longtext types are used restoring documents

5⃣ Numeric Data
Any numeric data can saved with same as text data samples (tiny, -, medium etc). And additionally, for decimals we have float(p,s) and double(p,s) types.

☑️ Temporal Data is refers to date type data. Types are date, datetime, timestamp, year and time.

6⃣ After visiting data types, let's see some samples of creating tables, inserting - update and delete data from table.

For that I will refer to my #github repo github.com/orkunaran/8wee…

7⃣ Insert Data
How to insert data into the created table

According to this table, we also need customer_names and products tables to determine products and customers.

8⃣ Let's UPDATE last row of the sales data, change product_id to 2

9⃣ And finally, let's delete one of the rows

In this query, I deleted customer A's orders which are 2.

🔚 That's the end for today. I know the book will cover these in detail in later chapters. However, this chapter was a good wrap-up.

I hope you liked the summaries I wrote here. See you tomorrow for a part of Chapter III (not sure I can finish it all )

All the best