sql - Oracle - 获取星期几

Question

今天是星期二。

为什么我运行这条 SQL 语句时，它说不是星期二？

SELECT 
CASE 
WHEN TO_CHAR(sysdate, 'Day') = 'Tuesday' THEN 'Its Tuesday'
ELSE 'Its Not Tuesday'  
END AS case_result,
TO_CHAR(sysdate, 'Day') AS day
FROM DUAL

回报：

CASE_RESULT DAY
It's Not Tuesday    Tuesday

Answer 1

像这样试试

SELECT CASE 
       WHEN trim(TO_CHAR(SYSDATE, 'Day')) = 'Tuesday' THEN 'Its Tuesday'
       ELSE 'Its Not Tuesday'  
       END AS case_result,
       TO_CHAR(SYSDATE, 'Day') AS DAY
FROM  DUAL;

或者按照 ajmalmhd04 的建议，你可以试试FmDay，

SELECT CASE 
       WHEN TO_CHAR(SYSDATE, 'FmDay') = 'Tuesday' THEN 'Its Tuesday'
       ELSE 'Its Not Tuesday'  
       END AS case_result,
       TO_CHAR(SYSDATE, 'Day') AS DAY
FROM  DUAL;

Answer 2

to_char(sysdate,'day') 的值实际上是 'tuesday'，在 tuesday 之后有两个空格。Oracle 将该值填充为最长一天的长度，即星期三，即 9 个字符。

尝试

RTRIM(to_char(sysdate,'day'))

Answer 3

嗯，这个：

SELECT TO_CHAR(sysdate, 'Day') FROM dual;

在我的国家说“Wtorek”......也许你用你的语言而不是英语来获得本周的名字？

您可以使用以下命令检查数据库中设置的日期语言：

SELECT * FROM nls_database_parameters WHERE parameter = 'NLS_DATE_LANGUAGE';

Answer 4

SELECT 
CASE 
WHEN rtrim(TO_CHAR(sysdate, 'Day')) = 'Tuesday' THEN 'Its Tuesday'
ELSE 'Its Not Tuesday'  
END AS case_result,TO_CHAR(sysdate, 'Day') AS day
FROM DUAL