groovy:合計請購單金額

groovy:合計請購單金額
Model Validator Table Event
====================
import groovy.sql.Sql
import java.sql.Timestamp
import java.sql.PreparedStatement
import java.sql.ResultSet
import org.compiere.util.Env
import org.compiere.util.DB
//  A_Ctx   A_PO  A_Type  A_Event

int client=Env.getContextAsInt(A_Ctx, "AD_Client_ID");
int org=Env.getContextAsInt(A_Ctx, "AD_Org_ID");
int uid=Env.getContextAsInt(A_Ctx, "#AD_User_ID");
//  int parent_id=Env.getContextAsInt(A_Ctx, "請購單_ID");
int parent_id=((Integer)A_PO.get_Value("請購單_ID")).intValue();

String sql = "SELECT SUM(本幣金額)  FROM 請購單明細 WHERE 請購單_id =? ";
PreparedStatement pstmt = DB.prepareStatement(sql, A_PO.get_TrxName());
pstmt.setInt(1, parent_id);
ResultSet rs = pstmt.executeQuery();
while (rs.next()) {
BigDecimal price = rs.getBigDecimal (1);

if (price ==null)  price = new BigDecimal(0);

DB.executeUpdateEx("UPDATE 請購單 SET 本幣金額合計="+price+"  WHERE 請購單_id ="+parent_id,  A_PO.get_TrxName());
}

rs.close();
pstmt.close();