import groovy.sql.Sql;
import groovy.sql.GroovyRowResult;
import java.sql.SQLException;

Sql connection;

String dbConnection = "jdbc:mysql://localhost:3306/jiradb?useUnicode=true&characterEncoding=UTF8&sessionVariables=storage_engine=InnoDB";
String dbDriver = "com.mysql.jdbc.Driver";
String dbUserid = "jiradbuser";
String dbPasswd = "JiraDBUser";
String quoteTable = "cost_of_repair_c10809";

try {
connection = Sql.newInstance( dbConnection, dbUserid, dbPasswd, dbDriver );
} catch (SQLException e) {
return "Unknown (Issue connecting to the database: ${e.getMessage()})";
}

GroovyRowResult result = null;
try {
    log.debug("issue = ${issue.id}");
    result = connection.firstRow("select sum(amount) subtotal from " + quoteTable + " where issueId = " + issue.id);
} catch (SQLException e) {
    log.debug ("Issue retrieving data from the database: " + e.getMessage())
    return 0D;
}

if (result == null) {
   // no value given
   return 0D;
}

return result.get("subtotal");