How to convert H2Database database file to MySQL database .sql file?

Question

I have some data in H2Database file and I want to convert it to MySQL .sql database file. What are the methods I can follow?

Answer 1

I created a Groovy script that does the migration from h2 to mysql. From there you could do a mysqldump. It requires that the tables exists in the Mysql database. It should work for ohter DBMS with minor changes.

@Grapes(
[ 
    @Grab(group='mysql', module='mysql-connector-java', version='5.1.26'),
    @Grab(group='com.h2database', module='h2', version='1.3.166'),
    @GrabConfig(systemClassLoader = true)
])

import groovy.sql.Sql

def h2Url='jdbc:h2:C:\\Users\\xxx\\Desktop\\h2\\sonardata\\sonar'
def h2User='sonar'
def h2Passwd='sonar'

def mysqlUrl='jdbc:mysql://10.56.xxx.xxx:3306/sonar?useunicode=true&characterencoding=utf8&rewritebatchedstatements=true'
def mysqlUser='sonar'
def mysqlPasswd='xxxxxx'
def mysqlDatabase='sonar'


sql = Sql.newInstance(h2Url, h2User, h2Passwd, 'org.h2.Driver' )

def tables = [:]

sql.eachRow("select * from information_schema.columns where table_schema='PUBLIC'") {
    if(!it.TABLE_NAME.endsWith("_MY")) {
        if (tables[it.TABLE_NAME] == null) {
            tables[it.TABLE_NAME] = []
        }
        tables[it.TABLE_NAME] += it.COLUMN_NAME;
    }
}

tables.each{tab, cols ->
    println("processing $tab")
    println("droppin $tab"+"_my")

    sql.execute("DROP TABLE IF EXISTS "+tab+"_my;")
    sql.execute("create linked table "+tab+"_my ('com.mysql.jdbc.Driver', '"+mysqlUrl+"', '"+mysqlUser+"', '"+mysqlPasswd+"', '"+mysqlDatabase+"."+tab.toLowerCase()+"');")

    sql.eachRow("select count(*) as c from " + tab + "_my"){println("deleting $it.c entries from mysql table")}
    result = sql.execute("delete from "+tab+"_my")
    colString = cols.join(", ")
    sql.eachRow("select count(*) as c from " + tab){println("starting to copy $it.c entries")}
    sql.execute("insert into " + tab + "_my ("+colString+") select "+colString+" from " + tab)
}