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.
The following example returns all rows that contain at least one numerical digit in PostgreSQL.
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.
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.
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).
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.
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.
The SQLite json_replace() function allows us to replace an existing value in a JSON document with another value.
We pass the original JSON as the first argument when we call the function, followed by the path of the value to replace, followed by the value to replace.
We can also replace multiple key/value pairs if required.
The SQLite json_set() function allows us to insert into, or replace, a value in a JSON document.
We pass the original JSON as the first argument when we call the function, followed by a path that specifies where to insert/replace the new value, followed by the value to insert/replace.
We can also insert/replace multiple key/value pairs if required.