标签：version 11g last tran eric xpl https sse some
TECHONTHENNTE WEBSITE: https://www.techonthenet.com/oracle/functions/to_char.php
This Oracle tutorial explains how to use the Oracle/PLSQL TO_CHAR function with syntax and examples.
The Oracle/PLSQL TO_CHAR function converts a number or date to a string.
The syntax for the TO_CHAR function in Oracle/PLSQL is:
TO_CHAR( value [, format_mask] [, nls_language] )
The TO_CHAR function returns a string value.
The TO_CHAR function can be used in the following versions of Oracle/PLSQL:
Let‘s look at some Oracle TO_CHAR function examples and explore how to use the TO_CHAR function in Oracle/PLSQL.
For example:
The following are number examples for the TO_CHAR function.
TO_CHAR(1210.73, ‘9999.9‘) Result: ‘ 1210.7‘ TO_CHAR(-1210.73, ‘9999.9‘) Result: ‘-1210.7‘ TO_CHAR(1210.73, ‘9,999.99‘) Result: ‘ 1,210.73‘ TO_CHAR(1210.73, ‘$9,999.00‘) Result: ‘ $1,210.73‘ TO_CHAR(21, ‘000099‘) Result: ‘ 000021‘
The following is a list of valid parameters when the TO_CHAR function is used to convert a date to a string. These parameters can be used in many combinations.
| 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.
TO_CHAR(sysdate, ‘yyyy/mm/dd‘) Result: ‘2003/07/09‘ TO_CHAR(sysdate, ‘Month DD, YYYY‘) Result: ‘July 09, 2003‘ TO_CHAR(sysdate, ‘FMMonth DD, YYYY‘) Result: ‘July 9, 2003‘ TO_CHAR(sysdate, ‘MON DDth, YYYY‘) Result: ‘JUL 09TH, 2003‘ TO_CHAR(sysdate, ‘FMMON DDth, YYYY‘) Result: ‘JUL 9TH, 2003‘ TO_CHAR(sysdate, ‘FMMon ddth, YYYY‘) Result: ‘Jul 9th, 2003‘
You will notice that in some TO_CHAR function examples, the format_mask parameter begins with "FM". This means that zeros and blanks are suppressed(vt. 镇压,使...止住,禁止. )This can be seen in the examples below.
TO_CHAR(sysdate, ‘FMMonth DD, YYYY‘) Result: ‘July 9, 2003‘ TO_CHAR(sysdate, ‘FMMON DDth, YYYY‘) Result: ‘JUL 9TH, 2003‘ TO_CHAR(sysdate, ‘FMMon ddth, YYYY‘) Result: ‘Jul 9th, 2003‘
The zeros have been suppressed so that the day component shows as "9" as opposed to "09".
Question: Why doesn‘t this sort the days of the week in order?
SELECT ename, hiredate, TO_CHAR((hiredate),‘fmDay‘) "Day" FROM emp ORDER BY "Day";
Answer: In the above SQL, the fmDay format mask used in the TO_CHAR function will return the name of the Day and not the numeric value of the day.
To sort the days of the week in order, you need to return the numeric value of the day by using the fmD format mask as follows:
SELECT ename, hiredate, TO_CHAR((hiredate),‘fmD‘) "Day" FROM emp ORDER BY "Day";
标签：version 11g last tran eric xpl https sse some
原文地址：http://www.cnblogs.com/yjhlsbnf/p/7819031.html
