In MySQL, the MEMBER OF() operator tests whether or not a value is a member of a given JSON array.
It returns true (1) if the array contains the value, and false (0) if it doesn’t.
The MEMBER OF() operator was added in MySQL 8.0.17.
Relational
How JSON_OVERLAPS() Works in MySQL
In MySQL, JSON_OVERLAPS() is a function that tests whether or not two JSON documents have any key-value pairs or array elements in common.
The function returns true (1) if the documents have any key-value pairs or array elements in common, and false (0) if they don’t.
The JSON_OVERLAPS() function was added in MySQL 8.0.17.
Fix ERROR 1050 “Table … already exists” in MariaDB
If you’re getting an error that reads something like “ERROR 1050 (42S01) at line 22: Table ‘Pets’ already exists” when trying to create a table in MariaDB, it’s most likely because there’s already a table in the database with the same name.
To fix this issue, either change the name of the table you’re trying to create, or check the existing table to see if it’s the one you actually need.
About the JSON_MERGE() Function in MySQL
In MySQL, JSON_MERGE() is a deprecated function that merges two or more JSON documents and returns the result.
It was deprecated in MySQL 8.0.3 and is subject to removal in a future release.
Fortunately, the JSON_MERGE_PRESERVE() function was added in MySQL 8.0.3 as a synonym for JSON_MERGE(), and it therefore does the same thing that JSON_MERGE() does/did.
Therefore, instead of using JSON_MERGE(), use JSON_MERGE_PRESERVE() instead.
Alternatively, you can use JSON_MERGE_PATCH(), which performs an RFC 7396 compliant merge of two or more JSON documents, without preserving members having duplicate keys.
How to Generate a CREATE TABLE Script for an Existing Table in MySQL
In MySQL, we can use the SHOW CREATE TABLE statement to generate a CREATE TABLE script for existing tables. This enables us to recreate the table without having to manually type out the table’s definition.
How JSON_TABLE() Works in MySQL
In MySQL, JSON_TABLE() is a built-in function that converts JSON data into a relational form.
In other words, it lets you return a JSON document as a table.
The JSON_TABLE() function was introduced in MySQL 8.0.
How to Return the Result of FOR XML as XML Data Type in SQL Server
In SQL Server, when we use FOR XML to return query results in an XML document, the resulting XML document is returned as a string by default. However, we can change this so that it’s returned in the xml data type.
To do this, all we need to do is append our query with the TYPE directive.
Add a Column that Cycles Through a Range of Numbers in a Result Set in SQL Server
If we ever need to assign repeating sequence numbers to a result set in SQL Server, we can use a sequence object with the appropriate arguments.
In particular, we can use the CYCLE argument to specify that the sequence will cycle through the range of numbers. In other words, once it reaches the end of the sequence, it starts again, and will continue to reiterate every time it completes the sequence.
How CAST() Works in MySQL
In MySQL, CAST() is a built in function that converts a value to another data type. It takes a value of one type and returns a value of the specified type.
You provide the value as an argument when you call the function, as well as the type that you’d like it converted to.
CAST() works similar to CONVERT(), except that the syntax used is slightly different.
Fix “ERROR 1298 (HY000): Unknown or incorrect time zone…” in MySQL
If you’re getting error 1298 that reads something like “ERROR 1298 (HY000): Unknown or incorrect time zone: ‘UTC’” in MySQL, it’s probably because you’re specifying a time zone name, but your MySQL installation hasn’t yet been configured for named time zones.
To fix this issue, be sure that your MySQL installation has been configured for named time zones.