HSQLDB语句和Java NaN加倍 [英] HSQLDB Statement and Java NaN doubles

问题描述

我目前正在使用HSQLDB保存Java数据.在这些数据中，有一些Double，其中一些可以具有NaN的值(在javadoc中描述为0.0/0.0). HSQLDB知道如何处理PreparedStatement的setDouble和setFloat中的这些值.问题是，我必须使用Statement对象，而不是预编译的存储过程，而我只是找不到使它工作的方法.
如果您有最小的提示，那将是最受欢迎的:)
谢谢.

I'm currently using HSQLDB to save java data. Within theses datas, there are some Double, and some of them can be of values of NaN (described as 0.0/0.0 in the javadoc). HSQLDB know how to handle these values in setDouble and setFloat of PreparedStatement. The thing is, I have to use a Statement object, not a precompiled stored procedure, and I just can't find a way to make it work.
If you had the tinyest hint, it would be most welcome :)
Thanks.

这是我正在使用的一堆代码:

EDIT : Here's the bunch of code I'm using :

stmt.executeUpdate("insert into Mesh(Id, name, dimension, meshtype, totalVolume, NumberOfCoarseCell) values (identity(), "  
                             + "'" + name_ + "',"  
                             + dimension_ + "," // this value can be NaN  
                             + "'" + type_.toString() + "',"   
                             + totalVolume_ + "," // this value can be NaN  
                             + numberOfCoarseCells_ + ")");  

推荐答案

使用HSQLDB 1.8.x，您可以将(0.0e1/0.0e1)用作返回NaN的表达式.

With HSQLDB 1.8.x you can use (0.0e1/0.0e1) as an expression that returns NaN.

例如:

create table t (d double)
insert into t values (0.0e1/0.0e1) 

对于HSQLDB 2.1及更高版本，必须使用SQL语句指定属性:

For HSQLDB 2.1 and above, an property must be specified with an SQL statement:

SET DATABASE SQL DOUBLE NAN FALSE

或作为连接属性:

hsqldb.double_nan=false

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