Java 如果记录不存在，则休眠插入
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Hibernate Insert if record does not exist
提问by cloudviz
How can I do this with Hibernate - If record does not exists insert it.
如何使用 Hibernate 执行此操作 - 如果记录不存在，请插入它。
I have the following columns
我有以下几列
Id (Primary Key), Ticker Symbol, Ticker Name, Industry, Sector, LastUpdate
Id（主键）、股票代码、股票名称、行业、部门、LastUpdate
I would like to check the records at Ticker Symbol Column if the string exist don't do anything if it does not exist then insert a new row with Id, Ticker Symbol, Ticker Name, Industry, Sector and Update Date (today's date).
如果字符串存在，我想检查代码符号列中的记录，如果它不存在，则不执行任何操作，然后插入一个包含 Id、代码符号、代码名称、行业、部门和更新日期（今天的日期）的新行。
I have gone as far as creating a new Table with the code below.
我已经使用下面的代码创建了一个新表。
//Hibernate Create a Session Factory
SessionFactory sessionFactory = new Configuration().configure().buildSessionFactory();
for (int i = 0; i < Bloomberg.getTickerSymbol().size(); i++){
//Hibernate to store Stock Tickers Data
tickerInfo.setTickerSymbol(Bloomberg.getTickerSymbol().get(i)); //Symbol
tickerInfo.setTickerName(Bloomberg.getTickerName().get(i)); //Name
tickerInfo.setTickerSector(Bloomberg.getTickerSector().get(i)); //Sector
tickerInfo.setTickerIndustry(Bloomberg.getTickerIndustry().get(i)); //Industry
tickerInfo.setTickerLastUpdate(Calendar.getInstance().getTime()); //Update Date
org.hibernate.Session session = sessionFactory.openSession();
session.beginTransaction();
session.saveOrUpdate(tickerInfo);
session.getTransaction().commit();
session.close();
}
采纳答案by Prabhakaran Ramaswamy
//Hibernate Create a Session Factory
SessionFactory sessionFactory = new Configuration().configure().buildSessionFactory();
for (int i = 0; i < Bloomberg.getTickerSymbol().size(); i++){
//Hibernate to store Stock Tickers Data
tickerInfo.setTickerSymbol(Bloomberg.getTickerSymbol().get(i)); //Symbol
tickerInfo.setTickerName(Bloomberg.getTickerName().get(i)); //Name
tickerInfo.setTickerSector(Bloomberg.getTickerSector().get(i)); //Sector
tickerInfo.setTickerIndustry(Bloomberg.getTickerIndustry().get(i)); //Industry
tickerInfo.setTickerLastUpdate(Calendar.getInstance().getTime()); //Update Date
org.hibernate.Session session = sessionFactory.openSession();
List tickerInfos = session.createCriteria(TickerInfo.class).add(Restrictions.eq("tickerSymbol", Bloomberg.getTickerSymbol().get(i))).list();
if(tickerInfos.size()<1){
session.beginTransaction();
session.saveOrUpdate(tickerInfo);
session.getTransaction().commit();
}
session.close();
}
回答by samblake
An option could be to create a unique constraint in your database, attempt the update, and catch the exception if the constraint is violated.
一个选项可能是在您的数据库中创建一个唯一约束，尝试更新，并在违反约束时捕获异常。
A better approach might be a mix this with a local cache of known added ticker symbols (assuming symbols are never removed), which should cut down to the amount of database calls being made.
更好的方法可能是将其与已知添加的股票代码的本地缓存混合（假设永远不会删除符号），这应该减少正在执行的数据库调用量。
