SQL SELECT Only Time from DateTime with Code Examples
In SQL, the DATETIME data type is used to store date and time information. However, there may be cases where you only need to select the time portion of the DATETIME value. In this article, we will discuss how to select only the time from a DATETIME value in SQL.
The first method to select only the time from a DATETIME value is to use the DATEPART() function. The DATEPART() function is used to extract a specific part of a date or time value. To select only the time from a DATETIME value, we can use the DATEPART() function with the 'hh', 'mi', and 'ss' parameters. Here is an example:
SELECT DATEPART(hh, GETDATE()) AS Hour, DATEPART(mi, GETDATE()) AS Minute, DATEPART(ss, GETDATE()) AS Second
FROM table_name
The above query will select the hour, minute, and second from the current date and time using the GETDATE() function.
Another method to select only the time from a DATETIME value is to use the CONVERT() function. The CONVERT() function is used to convert a value from one data type to another. To select only the time from a DATETIME value, we can use the CONVERT() function with the 'time' data type. Here is an example:
SELECT CONVERT(time, GETDATE()) AS Time
FROM table_name
The above query will select the time from the current date and time using the GETDATE() function and convert it to the 'time' data type.
A third method to select only the time from a DATETIME value is to use the CAST() function. The CAST() function is similar to the CONVERT() function and is used to convert a value from one data type to another. To select only the time from a DATETIME value, we can use the CAST() function with the 'time' data type. Here is an example:
SELECT CAST(GETDATE() AS time) AS Time
FROM table_name
The above query will select the time from the current date and time using the GETDATE() function and cast it to the 'time' data type.
In summary, to select only the time from a DATETIME value in SQL, you can use the DATEPART() function, CONVERT() function, or CAST() function with the appropriate parameters. Each of these methods will allow you to extract the time portion of a DATETIME value and return it as a separate value.
In addition to the methods discussed above, there are a few other ways to extract the time portion of a DATETIME value in SQL.
One approach is to use the TIME() function, which is available in some relational database management systems (RDBMS) such as MySQL. The TIME() function takes a DATETIME or TIMESTAMP value as an argument and returns the time portion of the value. Here's an example of how to use the TIME() function in MySQL:
SELECT TIME(date_column) AS Time
FROM table_name;
Another approach is to use string manipulation functions to extract the time portion from a DATETIME value. For example, in SQL Server, you can use the SUBSTRING() function to extract the time portion from a DATETIME value in the format 'hh:mm:ss':
SELECT SUBSTRING(CONVERT(VARCHAR(20), date_column, 108), 1, 8) AS Time
FROM table_name;
Similarly, in Oracle, you can use the SUBSTR() function to extract the time portion from a DATETIME value in the format 'hh:mi:ss':
SELECT SUBSTR(TO_CHAR(date_column, 'HH24:MI:SS'),1,8) AS Time
FROM table_name;
In addition to extracting the time portion of a DATETIME value, you may also need to format the time in a specific way. To do this, you can use the various date and time formatting functions provided by your RDBMS. For example, in SQL Server, you can use the CONVERT() function with a specific style code to format the time in a variety of ways:
SELECT CONVERT(VARCHAR(8), date_column, 108) AS Time -- returns time in format 'hh:mi:ss'
FROM table_name;
In MySQL, you can use the DATE_FORMAT() function to format the time in a specific way:
SELECT DATE_FORMAT(date_column, '%H:%i:%s') AS Time -- returns time in format 'hh:mi:ss'
FROM table_name;
In Oracle, you can use the TO_CHAR() function to format the time in a specific way:
SELECT TO_CHAR(date_column, 'HH24:MI:SS') AS Time -- returns time in format 'hh:mi:ss'
FROM table_name;
In conclusion, there are many ways to extract the time portion of a DATETIME value in SQL, each with its own set of pros and cons. The best method to use will depend on your specific requirements and the RDBMS you are working with. It's important to keep in mind that while all the above method will extract the time, they may return in different formats, so make sure to format it according to your needs.
Popular questions
- What is the DATETIME data type in SQL and why might you need to select only the time portion of a value of this type?
- The DATETIME data type in SQL is used to store date and time information. However, there may be cases where you only need to select the time portion of the DATETIME value and not the date.
- How can you use the DATEPART() function to select only the time from a DATETIME value?
- To select only the time from a DATETIME value, you can use the DATEPART() function with the 'hh', 'mi', and 'ss' parameters. For example:
SELECT DATEPART(hh, GETDATE()) AS Hour, DATEPART(mi, GETDATE()) AS Minute, DATEPART(ss, GETDATE()) AS Second FROM table_name
- How can you use the CONVERT() function to select only the time from a DATETIME value?
- To select only the time from a DATETIME value, you can use the CONVERT() function with the 'time' data type. For example:
SELECT CONVERT(time, GETDATE()) AS Time FROM table_name
- How can you use the CAST() function to select only the time from a DATETIME value?
- To select only the time from a DATETIME value, you can use the CAST() function with the 'time' data type. For example:
SELECT CAST(GETDATE() AS time) AS Time FROM table_name
- Are there any other ways to select only the time from a DATETIME value in SQL?
- Yes, there are other ways such as the TIME() function (in MySQL), string manipulation functions like SUBSTRING() and SUBSTR() and formatting functions like DATE_FORMAT(), CONVERT() and TO_CHAR(). The best method to use will depend on your specific requirements and the RDBMS you are working with.
Tag
Datetime
