我怎么能知道一个SQLException被抛出,因为外键冲突? [英] How can I know if an SQLexception was thrown because of foreign key violation?
问题描述
我想告诉大家,一个纪录没有被删除,因为它有子数据的用户,但我怎么能肯定的是,抛出异常,因为一个外键冲突?我看到有一个用于所有SQL异常抛出SQLException类。
I want to tell the user that a record was not deleted because it has child data, but how can I be sure that the exception was thrown because of a foreign key violation? I see that there a sqlexception class that is used for all sql exception.
推荐答案
您使用的是SQL Server的假设。
Assume you're using SQL Server.
使用德谷歌 - <一个href="http://blogs.msdn.com/tomholl/archive/2007/08/01/mapping-sql-server-errors-to-net-exceptions-the-fun-way.aspx" rel="nofollow">http://blogs.msdn.com/tomholl/archive/2007/08/01/mapping-sql-server-errors-to-net-exceptions-the-fun-way.aspx
try
{
# SQL Stuff
}
catch (SqlException ex)
{
if (ex.Errors.Count > 0) // Assume the interesting stuff is in the first error
{
switch (ex.Errors[0].Number)
{
case 547: // Foreign Key violation
throw new InvalidOperationException("Some helpful description", ex);
break;
case 2601: // Primary key violation
throw new DuplicateRecordException("Some other helpful description", ex);
break;
default:
throw new DataAccessException(ex);
}
}
}
案例547是你的男人。
Case 547 is your man.
更新以上是样品code和不应使用。请按照链接来解释为什么。
UPDATE The above is sample code and should not be used. Please follow the link as to explain why.
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