Oracle-为什么将数字的前导零转换为TO_CHAR时会消失 [英] Oracle - Why does the leading zero of a number disappear when converting it TO_CHAR

问题描述

在Oracle中，将带有前导零的数字转换为字符时，为什么会消失?此逻辑是Oracle特定的还是SQL特定的?

In Oracle, when converting a number with a leading zero to a character, why does the leading number disappear? Is this logic Oracle specific, or specific to SQL?

示例:

SELECT TO_CHAR(0.56) FROM DUAL;
/* Result = .56 */

推荐答案

这是Oracle提供的默认格式.如果要在输出中使用前导零，则需要显式提供格式.使用:

It's the default formatting that Oracle provides. If you want leading zeros on output, you'll need to explicitly provide the format. Use:

SELECT TO_CHAR(0.56,'0.99') FROM DUAL;

甚至:

SELECT TO_CHAR(.56,'0.99') FROM DUAL;

尾随零也是如此:

SQL> SELECT TO_CHAR(.56,'0.990') val FROM DUAL;

VAL
------
 0.560

TO_CHAR转换函数的一般形式为:

The general form of the TO_CHAR conversion function is:

TO_CHAR (数字， 查看全文