[20191104]sqlplus下显示数据精度2.txt

[20191104]sqlplus下显示数据精度2.txt --//以前写的链接如下: http://blog.itpub.net/267265/viewspace-2284458/=>[20181207]sqlplus下显示数据精度.txt --//才发现自己分析有误,实际上sqlplus缺省最大显示宽度占10个字符,是这个问题导致一些精度被截取. --//通过例子说明: 1.环境: SCOTT@book> @ ver1 PORT_STRING                    VERSION        BANNER ------------------------------ -------------- -------------------------------------------------------------------------------- x86_64/Linux 2.4.xx            11.2.0.4.0     Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production 2.测试: SCOTT@book> show numwidth numwidth 10 SCOTT@book> select sum(AMOUNT_SOLD),count(*) from sh.sales; SUM(AMOUNT_SOLD)   COUNT(*) ---------------- ----------       98205831.2     918843 --//98205831.2正好占用10个字符.实际以上sum精确结果是98205831.21,设置numwidth=11看看. SCOTT@book> set numw 11 SCOTT@book> select sum(AMOUNT_SOLD),count(*) from sh.sales; SUM(AMOUNT_SOLD)     COUNT(*) ---------------- ------------      98205831.21       918843 SCOTT@book> select 0.0000000000000000000123456789012 from dual ; 0.0000000000000000000123456789012 ---------------------------------                       1.23457E-20 --//显示输出占11个字符 SCOTT@book> set numw 10 SCOTT@book> select 0.0000000000000000000123456789012 from dual ; 0.0000000000000000000123456789012 ---------------------------------                        1.2346E-20 --//这个问题是一些细节问题,工作中应该引起注意.在toad下只要在 --//Data Grids    Display large numbers in Scientific Notation前面的勾不选上,基本没有问题,不受显示宽度限制.