Database Management Systems
In MariaDB, MID() is a synonym for SUBSTRING(). It returns a substring from a given string.
According to the MariaDB documentation it’s a synonym for the SUBSTRING(str,pos,len) syntax of SUBSTRING(), however, my tests show that it works with all of the various forms.
In MariaDB, SUBSTR() is a synonym for SUBSTRING().
It’s a built-in string function that returns a substring from a given string.
It requires at least two arguments; the string, and the position for which to extract the substring from. It also accepts an optional third argument that allows you to specify how long the substring should be.
Continue readingIn MariaDB, SUBSTRING() is a built-in string function that returns a substring from a given string.
SUBSTRING() requires at least two arguments; the string, and the position for which to extract the substring from. It also accepts an optional third argument that allows you to specify how long the substring should be.
MongoDB provides several ways to drop an index or indexes.
To drop a single index, you can use the dropIndex() method.
To drop multiple indexes, you can use either the dropIndexes() method or the dropIndexes administration command.
In MariaDB, MATCH AGAINST is a special construct used to perform a full-text search on a full-text index.
In MariaDB, COERCIBILITY() is a system function that returns the collation coercibility value of its string argument.
It defines how collations will be converted in the case of collation conflict. In such conflicts, an expression with a higher coercibility is converted to the collation of an expression with a lower coercibility.
Continue readingIf you connect to MariaDB using the command line interface, you might sometimes find that your query results are too wide, due to the number of columns being returned, and the data they contain.
Continue readingIn MariaDB, MAKE_SET() is a string function that returns a set value, based on the values provided in its arguments.
A set is a string containing substrings separated by comma (,) characters.
In MariaDB, TRIM_ORACLE() is a synonym for the Oracle mode version of the TRIM() function.
TRIM_ORACLE() is available in all modes, so it saves you from having to switch to Oracle mode, which is what you’d need to do if you wanted the TRIM() function to behave like Oracle’s TRIM() function.
The difference is in how each function treats empty strings. Oracle returns null whereas MariaDB returns an empty string.
In MariaDB, LTRIM_ORACLE() is a synonym for the Oracle mode version of the LTRIM() function.
LTRIM_ORACLE() is available in all modes, so it saves you from having to switch to Oracle mode, which is what you’d need to do if you wanted the LTRIM() function to behave like Oracle’s LTRIM() function.
The difference is in how each function treats empty strings. Oracle returns null whereas MariaDB returns an empty string.