Merge branch 'main' of https://github.com/CCH0124/codewars-sql

Author: CCH0124

Diff for: 7kyu/SQL-Padding-Encryption.md

@@ -0,0 +1,24 @@
+
+You are given a table with the following format:
+
+**encryption table schema**
+
+- md5
+- sha1
+- sha256
+
+Problem is the table looks so unbalanced - the sha256 column contains much longer strings. You need to balance things up. Add '1' to the end of the md5 addresses as many times as you need to to make them the same length as those in the sha256 column. Add '0' to the beginning of the sha1 values to achieve the same result.
+
+Return as:
+
+**output table schema**
+
+- md5
+- sha1
+- sha256
+
+```sql
+/*  SQL  */
+SELECT CONCAT(md5, REPEAT('1', LENGTH(sha256) - LENGTH(md5))) as md5, CONCAT(REPEAT('0', LENGTH(sha256)- LENGTH(sha1)), sha1) as sha1, sha256
+FROM encryption;
+```

Diff for: 7kyu/SQL-Right-and-Left.md

@@ -0,0 +1,33 @@
+You are given a table named repositories, format as below:
+
+**repositories table schema**
+
+- project
+- commits
+- contributors
+- address
+
+The table shows project names of major cryptocurrencies, their numbers of commits and contributors and also a random donation address ( not linked in any way :) ).
+
+For each row: Return first x characters of the project name where x = commits. Return last y characters of each address where y = contributors.
+
+Return project and address columns only, as follows:
+
+**output table schema**
+
+- project
+- address
+
+Case should be maintained.
+
+```sql
+/*  SQL  */ 
+SELECT substring(project,0, commits+1) as project, substring(address,(LENGTH(address)-contributors)+1, LENGTH(address)) as address FROM repositories
+```
+
+OR
+
+```sql
+/*  SQL  */
+SELECT LEFT(project, commits) as project, RIGHT(address, contributors) as address FROM repositories;
+```

Diff for: README.md

@@ -46,6 +46,8 @@
 |8 kyu|Easy SQL: LowerCase|[link](/8kyu/Easy-SQL-LowerCase.md)|`LOWER`|
 |7 kyu|SQL: Concatenating Columns|[link](/7kyu/SQL-Concatenating-Columns.md)|`CONCAT`|
 |7 kyu|SQL Basics - Trimming the Field|[link](/7kyu/SQL-Basics-Trimming-the-Field.md)|`split_part`|
+|7 kyu|SQL: Right and Left|[link](/7kyu/SQL-Right-and-Left.md)|`LEFT`、`RIGHT`、`substring`|
+|7 kyu|SQL: Padding Encryption|[link](/7kyu/SQL-Padding-Encryption.md)|`REPEAT`、`CONCAT`|
 
 ## 聚合
 |難度|題目|答案|使用的函數|