In SQL Server, the TRY_PARSE() function returns the result of an expression, translated to the requested data type, or NULL if the conversion fails.
Basically, it works the same as the PARSE() function, except that it returns NULL instead of an error if the cast fails.
Both functions are intended for converting string values to either date/time or number types.
Continue readingIn SQL Server, the PARSE() function returns the result of an expression, translated to the requested data type.
Basically, it enables us to parse a string expression to the specified data type. It’s intended for converting string values to either date/time or number types.
The PARSE() function can be handy when attempting to convert with CAST() or CONVERT() fails. The PARSE() function is able to parse the expression, and this may result in certain values being converted that wouldn’t normally be able to be converted.
When it comes to converting date and time values in SQL Server, things can get a little complex. But in this article I hope to demystify this topic for anyone who’s confused when it comes to making conversions between dates and other data types, as well as changing the format of date/time values, and other considerations.
Let’s jump straight in.
Continue readingIn SQLite, we can use the TIME() function to add a given number of minutes to a time value.
If we’re dealing with datetime values, we can use the DATETIME() function.
In PostgreSQL, we can use the + operator to add one or more minutes to a time value.
By “time” value, this could be an actual time value, a timestamp, or an interval. We can also add minutes to a date value or a date and time combination.
In SQLite, we can use the TIME() function to add a given number of hours to a time value.
If we’re dealing with datetime values, we can use the DATETIME() function.
In PostgreSQL, we can use the - operator to subtract one or more seconds from a time value.
By “time” value, this could be an actual time value, a timestamp, or an interval. We can also subtract seconds from a date value or a date and time combination.
Below are examples of using SQL to return the first day of the month across various DBMSs.
This could be the first day of the current month, or the first day of a month based on a given date.
Continue readingIn SQLite, we can use the DATE() function to subtract one or more months from a date.
For datetime values, we can use the DATETIME() function.
We can use SQLite’s DATE() function to return the first, second, third, fourth, etc instance of a given day within a given year.
We can use the same technique to return the first Monday of each month in the year.
It’s not limited to Monday though. The same techniques can be used on Tuesday, Wednesday, Thursday, Friday, etc.
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