无法向Oracle表插入日期数据：ORA-01843错误求助

Hey there, let's get that date insertion error sorted out! The ORA-01843 error pops up because Oracle can't parse the date string you're using—your session's default date format doesn't match the '2019-06-19' format you're passing in. Here are three reliable ways to fix this:

1. Use TO_DATE() to Explicitly Define the Date Format #

This is the most robust approach because it works regardless of your session's default settings. Wrap your date string in the TO_DATE() function and specify the format mask so Oracle knows exactly how to interpret each part:

INSERT INTO TEST.SUPPLIER (SUPPLIER_ID, SUPPLIER_NAME, CONTACT_NAME, DOB)
VALUES(6, 'rr', 'ss', TO_DATE('2019-06-19', 'YYYY-MM-DD'));

The 'YYYY-MM-DD' mask tells Oracle to read the string as year-month-day, eliminating any confusion.

2. Use an ANSI Date Literal #

Oracle supports ANSI standard date literals, which use a fixed YYYY-MM-DD format. This is a clean, concise alternative that doesn't require a format mask:

INSERT INTO TEST.SUPPLIER (SUPPLIER_ID, SUPPLIER_NAME, CONTACT_NAME, DOB)
VALUES(6, 'rr', 'ss', DATE '2019-06-19');

Oracle recognizes this syntax automatically, so you don't have to worry about session settings.

3. Adjust Your Session's Date Format (Temporary Fix) #

If you prefer using plain string dates, you can temporarily update your session's default date format to match your input. First, check your current format:

SELECT VALUE FROM NLS_SESSION_PARAMETERS WHERE PARAMETER = 'NLS_DATE_FORMAT';

If the result isn't 'YYYY-MM-DD', run this to update it:

ALTER SESSION SET NLS_DATE_FORMAT = 'YYYY-MM-DD';

Then execute your original INSERT statement. Note: this change only applies to your current session—once you log out, it will revert to the system default.

Why This Happened #

Most Oracle environments use a default date format like 'DD-MON-RR' (e.g., '19-JUN-19'). When you pass '2019-06-19', Oracle tries to interpret -06- as a month abbreviation, which it doesn't recognize—hence the "not a valid month" error.

内容的提问来源于stack exchange，提问作者Sravya Varshini