In SQLite, the -> operator extracts a subcomponent from a JSON document and returns a JSON representation of that subcomponent.
The -> operator was first introduced in SQLite version 3.38.0 (released on 22 February 2022).
Subtract Years from a Date in PostgreSQL
In PostgreSQL, we can use the - operator to subtract one or more years from a date.
Fix “ERROR 1136 (21S01): Column count doesn’t match value count at row 1” when Inserting Data in MariaDB
If you find yourself getting an error that reads something like “ERROR 1136 (21S01): Column count doesn’t match value count at row” in MariaDB, it’s probably because you’ve specified the wrong number of expressions for the number of columns in the column when attempting to insert data into a table.
In other words, you’re trying to insert too many columns or not enough columns.
7 Ways to Return Duplicate Rows that have a Primary Key in MariaDB
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.
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.