Toad中SQL查询日期时间戳及解决日期匹配报错问题

Hey there! Let's tackle your two Toad/SQL questions one by one, nice and clear:

The exact approach depends on what you need and the database you're using (I'm guessing Oracle since your second error is common there), but here are the most common scenarios:

• Get the current system timestamp (includes date, time, and time zone):

  SELECT SYSTIMESTAMP FROM DUAL;
  

  Or if you want the timestamp based on your session's time zone:

  SELECT CURRENT_TIMESTAMP FROM DUAL;
  

• Convert an existing date column (like your CREATE_DATE) to a timestamp:

  SELECT CAST(CREATE_DATE AS TIMESTAMP) FROM YOUR_TABLE;
  

That error pops up because your database's default date format doesn't match the string format you're using for comparison. For example, Oracle often uses formats like DD-MON-RR (e.g., 09-OCT-20) by default, but you're passing MM/DD/YYYY HH:MI:SS AM. Here are three solid fixes:

Option 1: Use TO_DATE to explicitly define your string format #

This is the most reliable way, since it works regardless of session settings:

SELECT * FROM YOUR_TABLE 
WHERE CREATE_DATE = TO_DATE('10/9/2020 2:05:10 AM', 'MM/DD/YYYY HH:MI:SS AM');

• MM = two-digit (or single-digit) month
• DD = day of the month
• HH = 12-hour clock time
• AM = handles the morning/evening indicator

Option 2: If CREATE_DATE is a TIMESTAMP column #

Use TO_TIMESTAMP instead of TO_DATE:

SELECT * FROM YOUR_TABLE 
WHERE CREATE_DATE = TO_TIMESTAMP('10/9/2020 2:05:10 AM', 'MM/DD/YYYY HH:MI:SS AM');

Option 3: Temporarily change your session's date format #

If you want to use your original query without conversion functions, run this first to adjust your session's date format:

ALTER SESSION SET NLS_DATE_FORMAT = 'MM/DD/YYYY HH:MI:SS AM';

Then you can execute your original SELECT * FROM YOUR_TABLE WHERE CREATE_DATE = '10/9/2020 2:05:10 AM'; query. Just note this only lasts for your current Toad session—close and reopen Toad, and you'll need to run the ALTER SESSION command again.

Quick tip: #

Always double-check what data type your CREATE_DATE column is (DATE vs TIMESTAMP) — you can find this in Toad's Schema Browser by looking at your table's columns. DATE types in Oracle do include time data, they just might not show it by default in Toad's results.

内容的提问来源于stack exchange，提问作者vishal gupta