错误：不存在关系 [英] ERROR: relation does not exist

问题描述

这就是问题所在。我用Java抓取了一些数据，最终我将该Java放入了postgres数据库。当我运行Java程序时，出现错误ERROR：关系表名不存在，但是当我亲自在PGAdmin III中编写相同的查询时，它可以正常工作。我用Google搜索了它，但这并不是大多数人都遇到的大写字母。这是屏幕截图：

So here is the problem. I am scraping some data with java and eventually i place that java into postgres database. When i run Java program, i get error ERROR: relation "table name" does not exist but when i personally write that same query in PGAdmin III, it works fine. I googled it and it's not about caps letters that most people have problems with. Here is a screenshot:

推荐答案

我首先想到的是您在对值使用双引号，但是随后我再次查看并意识到您正在使用字符串连接来组装查询

My first thought was that you were using double quotes for values, but then I looked again and realized you were assembling a query using string concatenation.

不要这样做。除了使这些问题无法调试之外，您还可以进行sql注入。

DON'T DO THAT. In addition to making these problems impossible to debug you open yourself up to sql injection.

在调试类似的东西时，您应该首先移植以使用占位符语法（PostgreSQL的JDBC驱动程序支持该语法），然后，如果不起作用，则发布服务器日志。

In debugging something like this, you should first port to use placeholder syntax (which PostgreSQL's JDBC driver supports) and then, if that doesn't work, then post the server logs.

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