An abstract type for a query parameter. Only the backend knows the actual type.

A designated value to replace a missing parameter. For SQL, null is NULL.

option f None is null and option f (Some x) is f x.

Constructs a boolean parameter. If the database does not have booleans, an integer value of 0 for false and 1 for true is used.

Constructs an integer parameter. The remote end may have a different range. For SQL, works with all integer types.

Constructs an integer parameter. The remote end may have a different range. For SQL, works with all integer types.

Constructs an integer parameter. The remote end may have a different range. For SQL, works with all integer types.

Constructs a floating point parameter. Note that the precision in the database may be different from that of the OCaml float. If conversion to string is requried by the backend, this is done with the %.*g format specifier, which may incur a small loss of precision, as well.

Given an UTF-8 encoded text, constructs a textual parameter with backend-specific encoding.

Constructs a parameter from an arbirary octet string. For SQL, the parameter is compatible with the BINARY type.

Construct a date paramater from a string using ISO 8601 format.

Construct a date parameter from the year, month, and day of the month, using the literal enumeration. I.e. Epoch is (1970, 1, 1).

Construct a parameter representing a date.

Construct a parameter representing date and time in the UTC time zone, converted from a float representing the number of non-leap seconds passed since 1970-01-01T00:00:00Z.

Create a parameter for an UTC timestamp field from a UTC time string in ISO 8601 format.

Construct a parameter representing an date and time in the UTC time zone.