Tag Archives: mysql

MySQL Stored Procedure for CRUD Dynamic Queries

The new MySQL 5.7 version has some great features. One of them is the ‘JSON data’ type. We can use it for column of table like ‘Virtual Colunm’ with Indexing. But, ‘JSON data’ is also useful for stored procedure. Because we can compact parameters and the procedure could be more flexible.I made the procedures for table insert/update via JSON parameter. When I apply them to my project, data-handling codes in the application decreased dramatically. (These procedures impliment ‘MySQL Procedure Pattern for Nested Transaction‘) The code below is an old version. The ‥‥‥

Mysql Backup Script


Features Full Backup (Mysqldump) Incremental Backup (Bin-log) Local Backup & Remote(AWS S3) Upload Sample Environments MySQL bin log prefix : mysql-bin BINLOG_PATH=/home/mysql/data BACKUP_ROOT=/home/backup/mysql S3_PATH=s3://system-backup/{SyatemName}/mysql


Don’t use utf8 encoding in MySQL (>= 5.5.3)


오늘날 한국어/중국어/일본어등 2바이트 문자권에서의 SW개발 및 다국어를 대비한 문자열 인코딩은 거의 UTF-8로 통일화 되고 있다. 그런데, MySQL의 문자인코딩 중 utf8인코딩은 ‘진짜 UTF-8’이 아니다 ! 원래 UTF-8은 규약상 한 문자가 4바이트까지 사용하는데 MySQL의 utf8인코딩은 3바이트까지만 입력이 가능하기 때문이다. 대부분의 한중일 문자는 3바이트 코드로  표현이 가능한데, 특히 특수문자나 한자를 많이 사용하는 일본어 등에서는 심심치 않게 4바이트 문자에 의한 문제가 나타난다. ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ‥‥‥

MySQL Procedure Pattern for Nested Transaction


The MySQL dose not supports ‘Nested Transaction’. Transactions cannot be nested. This is a consequence of the implicit commit performed for any current transaction when you issue a START TRANSACTION statement or one of its synonyms. (https://dev.mysql.com/doc/refman/5.7/en/implicit-commit.html) But I want to use ‘Stored Procedure’ what work well with a transaction independently and with nested calling. This pattern isn’t correct nested transactions, but enables the use of nested procedures. The basic idea is to use the @@ AUTOCOMMIT environment variable. The procedure will determine whether the transaction is started from the ‥‥‥

MySQL, Checking the IP address in a range

fn_ipv4_match( needle, haystack ) Returns 1 if haystack contains needle. needle : IPv4 address haystack : IPv4 address, IPv4 address with subnet mask, IPv4 address with netmask bits