Database Management Systems
In Oracle, the REGEXP_INSTR() function searches a string for a regular expression pattern. It returns an integer indicating the beginning or ending position of the matched substring (whichever one you specify).
It extends the functionality of the INSTR() function by allowing us to use regular expression patterns.
If you have a MongoDB collection with dates stored as strings, you can convert those into the Date BSON type if required.
Below are three ways to convert a string into a Date in MongoDB.
Continue readingIn Oracle, the NLS_LOWER() function returns its argument with all letters in lowercase.
It’s similar to the LOWER() function, except that it accepts a second argument that allows you to specify the collation. The collation handles special linguistic requirements for case conversions.
In Oracle, the NLS_UPPER() function returns its argument with all letters in uppercase.
It’s similar to the UPPER() function, except that it accepts a second argument that allows you to specify the collation. The collation handles special linguistic requirements for case conversions.
Occasionally you might find yourself in the situation where you need to get the name of the current workstation that’s connected to SQL Server.
For example, maybe you have a stored procedure that inserts data, and you want to record the name of the workstation that inserted the data.
In such cases, you can use the HOST_NAME() function.
This is not to be confused with getting the server name.
Continue readingIn Oracle, the RPAD() function allows you to pad the right part of a string with a certain character, to a specified number of characters.
The way it works is, you specify how long the resulting string should be. If the original string is shorter, the padding character fills in the remaining space.
Continue readingIn Oracle, the LPAD() function allows you to pad the left part of a string with a certain character, to a specified number of characters.
The way it works is, you specify how long the resulting string should be. If the original string is shorter, the padding character fills in the remaining space.
Continue readingTwo similar functions in MariaDB are FIELD() and FIND_IN_SET(). At first glance, these appear to do the same thing, but there is a difference.
This article looks at the difference between these two functions.
Continue readingIn Oracle, the TRANSLATE() function allows you to make several single-character, one-to-one substitutions in one operation.
It returns the string provided as a first argument after some characters specified in the second argument are translated into a destination set of characters specified in the third argument.
It’s similar to the REPLACE() function, except that the REPLACE() function replaces the whole string with another string (i.e. not character by character, like TRANSLATE() does).
In Oracle, the NLSSORT() function returns a collation key for a given character value and an explicitly or implicitly specified collation.
The function can be useful for performing comparisons against string values based on a specified collation.
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