Database Management Systems
In SQL Server, a recovery model is a database property that controls how transactions are logged, whether the transaction log requires (and allows) backing up, and what kinds of restore operations are available. Databases can use one of the following three recovery models: simple, full, and bulk-logged.
You can query the sys.databases catalog view to get a list of databases and their recovery models.
Here are two ways you can use SQLcl or SQL*Plus to check your Oracle Database compatibility level.
Continue readingIf you get warning number 1287 that reads ‘BINARY expr’ is deprecated and will be removed in a future release. Please use CAST instead when running a query in MySQL, it’s because you’re using the BINARY operator.
The BINARY operator is deprecated as of MySQL 8.0.27.
To fix the issue, cast the value to binary using the CAST() function instead.
If you need to find rows that contain lowercase letters in SQL Server, you could try one of the following options.
Continue readingWhen using psql, null values are returned as an empty string by default.
This can easily be changed with the \pset command, so it could be a value other than the default empty string.
If you’re not sure what your current value is, you can use the show \pset null command to show the current value.
In MariaDB, we can use the FORMAT() function to format a number with commas.
More specifically, the function returns the number as a formatted string, with thousands separators and a decimal separator, and rounded to the given decimal position.
Continue readingIf you’re getting SQL Server error Msg 241 that reads Conversion failed when converting date and/or time from character string, it’s probably because you’re trying to convert a string to a date/time value, but that particular string can’t be converted to the date/time type specified.
Continue readingT-SQL doesn’t include the IF NOT EXISTS clause with its CREATE TABLE statement, like some other DBMSs do.
Therefore, if we want to check for the existence of the table before we create it in SQL Server, we need to use other methods.
Continue readingThe following example returns all rows that don’t contain any numbers in SQLite.
By “number” I mean “numerical digit”. Numbers can also be represented by words and other symbols, but for the purpose of this article, we’re returning values that don’t contain any numerical digits.
Continue readingMariaDB provides several ways to perform arithmetic on dates. This includes adding or subtracting a day (or many days) from a given date.
Here’s an example of subtracting a day from a date in MariaDB.
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