Here are seven ways to return duplicate rows in MariaDB when those rows have a primary key or other unique identifier column.
Therefore, the duplicate rows share exactly the same values across all columns except for their unique identifier column.
Ian
SQLite JSON_TREE()
In SQLite, json_tree() is a table-valued function that walks the JSON value provided as its first argument and returns a table consisting of one row for each array element or object member.
We provide the JSON value as an argument when we call the function.
SQLite JSON_EACH()
In SQLite, json_each() is a table-valued function that walks the JSON value provided as its first argument and returns a table consisting of one row for each array element or object member.
We provide the JSON value as an argument when we call the function.
Detect Whether a Value Contains at Least One Numerical Digit in PostgreSQL
The following example returns all rows that contain at least one numerical digit in PostgreSQL.
SQLite JSON_TYPE()
The SQLite json_type() function returns the type of the outermost element of the given JSON.
We provide the JSON as an argument when we call the function.
We can optionally pass a path, which allows us to get the type of a specific array element or object member within the JSON.
SQLite JSON_QUOTE()
In SQLite, the json_quote() function converts a number or string into its corresponding JSON representation.
We provide the number or string as an argument when we call the function, and the function returns a JSON representation of that value.
SQLite JSON_REMOVE()
We can use the SQLite json_remove() function to remove one or more elements from a JSON object or array.
We pass the original JSON as the first argument when we call the function, followed by one or more paths that specify which elements to remove. By “elements”, I mean either array elements or object members (key/value pairs).
SQLite JSON_PATCH()
In SQLite, the json_patch() function can be used to add, modify, or delete elements of a JSON Object.
To do this, it runs the RFC-7396 MergePatch algorithm to apply a given patch against the given JSON input.
We pass the original JSON as the first argument when we call the function, followed by the patch. The function then applies that patch against JSON in the first argument.
Fix “ERROR 3942 (HY000): Each row of a VALUES clause must have at least one column” when using the VALUES Statement in MySQL
If you’re getting an error that reads “ERROR 3942 (HY000): Each row of a VALUES clause must have at least one column” in MySQL, you could have an empty row constructor when using the VALUES statement.
To fix this issue, make sure you’ve got at least one value in each ROW() clause within the VALUES statement.