oracle to_char()函数用法详解
TO_CHAR函数的Oracle / PLSQL，数字或日期转换为一个字符串。
to_char函数的语法是：
to_char( value, [ format_mask ], [ nls_language ] )
值可以是数字或日期将被转换为一个字符串。
format_mask是可选的。这是将要使用的格式转换成一个字符串值。
NLS_LANGUAGE是可选的。这是免入息审查贷款计划的语言，用于转换为字符串的值。
Applies To:
| 代码如下 | 复制代码 |
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Oracle 8i, Oracle 9i, Oracle 10g, Oracle 11g |
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实例
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to_char(1210.73, '9999.9') would return '1210.7' |
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日期实例
下面是一个有效参数列表to_char函数是用来转换为一个字符串的日期。这些参数可用于在多种组合。
| Parameter | Explanation |
|---|---|
| YEAR | Year, spelled out |
| YYYY | 4-digit year |
| YYY YY Y |
Last 3, 2, or 1 digit(s) of year. |
| IYY IY I |
Last 3, 2, or 1 digit(s) of ISO year. |
| IYYY | 4-digit year based on the ISO standard |
| Q | Quarter of year (1, 2, 3, 4; JAN-MAR = 1). |
| MM | Month (01-12; JAN = 01). |
| MON | Abbreviated name of month. |
| MONTH | Name of month, padded with blanks to length of 9 characters. |
| RM | Roman numeral month (I-XII; JAN = I). |
| WW | Week of year (1-53) where week 1 starts on the first day of the year and continues to the seventh day of the year. |
| W | Week of month (1-5) where week 1 starts on the first day of the month and ends on the seventh. |
| IW | Week of year (1-52 or 1-53) based on the ISO standard. |
| D | Day of week (1-7). |
| DAY | Name of day. |
| DD | Day of month (1-31). |
| DDD | Day of year (1-366). |
| DY | Abbreviated name of day. |
| J | Julian day; the number of days since January 1, 4712 BC. |
| HH | Hour of day (1-12). |
| HH12 | Hour of day (1-12). |
| HH24 | Hour of day (0-23). |
| MI | Minute (0-59). |
| SS | Second (0-59). |
| SSSSS | Seconds past midnight (0-86399). |
| FF | Fractional seconds. |
The following are date examples for the to_char function.
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| to_char(sysdate, 'yyyy/mm/dd'); would return '2003/07/09' to_char(sysdate, 'Month DD, YYYY'); would return 'July 09, 2003' to_char(sysdate, 'FMMonth DD, YYYY'); would return 'July 9, 2003' to_char(sysdate, 'MON DDth, YYYY'); would return 'JUL 09TH, 2003' to_char(sysdate, 'FMMON DDth, YYYY'); would return 'JUL 9TH, 2003' to_char(sysdate, 'FMMon ddth, YYYY'); would return 'Jul 9th, 2003' |
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你会发现，在一些例子中，format_mask参数与“FM”开始。这意味着，零和空格被抑制。这在下面的例子可以看出。
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to_char(sysdate, 'FMMonth DD, YYYY'); would return 'July 9, 2003' |
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补充：数据库,Oracle教程
