Add like

README.md

@@ -1,9 +1,9 @@
-# peyman.blog
+# SQL by example
 
 ## Setup
-Install extended version of hugo.
-Run server: `hugo server`.
-Create a new post: `hugo new --kind post posts/<post-name>.md`
+Install extended version of hugo.  
+- Run development server: `hugo server`.  
+- Create a new post: `hugo new --kind post posts/<post-name>.md`  
 
 ## TODO
 - [x] SELECT
@@ -14,17 +14,17 @@ Create a new post: `hugo new --kind post posts/<post-name>.md`
 - [x] ORDER BY
 - [x] GROUP BY
 - [x] AND, OR, NOT
-- [ ] Operators
 - [x] AS (Alias)
 - [x] LIMIT
 - [x] Comments
-- [ ] SELECT DISTINCT
-- [ ] IN
-- [ ] LIKE
+- [x] LIKE
 - [x] MIN, MAX
 - [x] COUNT
 - [x] SUM
 - [x] AVG
+- [ ] SELECT DISTINCT
+- [ ] IN
+- [ ] Operators
 - [ ] BETWEEN
 - [ ] ROUND
 - [ ] JOIN
@@ -43,6 +43,7 @@ Create a new post: `hugo new --kind post posts/<post-name>.md`
 - [ ] NULL
 - [ ] ALTER TABLE
 - [ ] TRUNCATE
+- [ ] SIMILAR TO https://www.postgresql.org/docs/16/functions-matching.html
 
 - [ ] Constraints
 - [ ] Unique

content/posts/comment.md

@@ -2,7 +2,7 @@
 title: "Comment"
 date: 2024-02-03T15:11:15+03:30
 tags:
-- intro
+- query
 - postgresql
 ---
 When you writing multiline SQL queries you can use `--` to comment a single line and 

content/posts/like.md

@@ -0,0 +1,94 @@
+---
+title: "LIKE"
+date: 2024-02-05T11:17:10+03:30
+tags:
+- query
+- postgresql
+---
+`LIKE` is use in `WHERE` condition to find data based on a pattern.  
+There are two wildcards that we can use with `LIKE`:  
+- `%`: represents zero, one, or multiple characters
+- `_`: represents one, single character.
+```sql
+-- find all users with first_name of John
+SELECT
+  id,
+  first_name,
+  last_name
+FROM users
+WHERE first_name LIKE 'John';
+-- +-----+------------+-----------+
+-- | id  | first_name | last_name |
+-- |-----+------------+-----------|
+-- | 14  | John       | Combs     |
+-- | 51  | John       | Fritz     |
+-- | 285 | John       | Sanders   |
+-- | 445 | John       | Wise      |
+-- | 485 | John       | Peterson  |
+-- | 501 | John       | Moreno    |
+-- | 502 | John       | Moreno    |
+-- +-----+------------+-----------+
+
+-- find all users that their first_name starts with A
+SELECT
+  id,
+  first_name,
+  last_name
+FROM users
+WHERE first_name LIKE 'A%';
+-- +-----+------------+-----------+
+-- | id  | first_name | last_name |
+-- |-----+------------+-----------|
+-- | 13  | Andrew     | Mercado   |
+-- | 42  | Adrian     | Ewing     |
+-- | 74  | Audrey     | Edwards   |
+
+-- find all users that their first_name ends with n
+SELECT
+  id,
+  first_name,
+  last_name
+FROM users
+WHERE first_name LIKE '%n';
+-- +-----+------------+-----------+
+-- | id  | first_name | last_name |
+-- |-----+------------+-----------|
+-- | 1   | Carmen     | Malone    |
+-- | 3   | Brandon    | Jenkins   |
+-- | 7   | Jocelyn    | Williams  |
+-- | 10  | Steven     | Perez     |
+-- ...
+
+-- find all users that their first_name contains n
+SELECT
+  id,
+  first_name,
+  last_name
+FROM users
+WHERE first_name LIKE '%n%';
+-- +-----+------------+-----------+
+-- | id  | first_name | last_name |
+-- |-----+------------+-----------|
+-- | 1   | Carmen     | Malone    |
+-- | 2   | Stephanie  | Wallace   |
+-- | 3   | Brandon    | Jenkins   |
+-- | 5   | Jennifer   | Smith     |
+-- ...
+
+-- find all users that their first_name is 4 character and ends with arl
+SELECT
+  id,
+  first_name,
+  last_name
+FROM users
+WHERE first_name LIKE '_arl';
+-- +-----+------------+------------+
+-- | id  | first_name | last_name  |
+-- |-----+------------+------------|
+-- | 59  | Earl       | Livingston |
+-- | 210 | Carl       | Gonzalez   |
+-- | 382 | Karl       | Pierce     |
+-- | 412 | Earl       | Owens      |
+-- +-----+------------+------------+
+```
+[PostgreSQL docs](https://www.postgresql.org/docs/16/functions-matching.html#FUNCTIONS-LIKE)