dataSource_target {
dialect = org.hibernate.dialect.MySQLInnoDBDialect
pooled = true
jmxExport = true
driverClassName = "com.mysql.jdbc.Driver"
username = "bla"
password = "bla"
}

static mapping = {
    datasource 'ALL'
 }

con = new Sql(dataSource_target)
         rows = con.rows(sql)

dataSource_target {
  dialect = org.hibernate.dialect.MySQLInnoDBDialect
  pooled = true
  jmxExport = true
  driverClassName = "com.mysql.jdbc.Driver"
  username = "bla"
  password = "bla"
  properties {
    maxActive = -1
    minEvictableIdleTimeMillis=1800000
    timeBetweenEvictionRunsMillis=1800000
    numTestsPerEvictionRun=3
    testOnBorrow=true
    testWhileIdle=true
    testOnReturn=true
    validationQuery="SELECT 1"
  }
}

def db = [
  url:'jdbc:hsqldb:mem:testDB',
  user:'sa',
  password:'',
  driver:'org.hsqldb.jdbc.JDBCDriver'
]
def sql = Sql.newInstance(db.url, db.user, db.password, db.driver)

def db = [:]
def dataSources = Holders.grailsApplication.config.dataSources
db.user = dataSources.dataSource_otherDsn.username
db.password = dataSources.dataSource_otherDsn.password
db.driver = dataSources.dataSource_otherDsn.driverClassName
if (Environment.current == Environment.DEVELOPMENT) {
    db.url = Holders.grailsApplication.config.environments.development.dataSources.dataSource_otherDsn.url
} else if (Environment.current == Environment.PRODUCTION) {
    db.url = Holders.grailsApplication.config.environments.production.dataSource.dataSource_otherDsn.url

}
def sql = Sql.newInstance(db.url, db.user, db.password, db.driver)