Interface IScalarFunctions
A dialect's renderer for the cross-provider scalar string/number functions of
CommonFunctions (left/right, lpad/rpad,
repeat/reverse/space, concat_ws, translate, ascii/char,
bit_length/octet_length, cot/degrees/radians/pi). The
predicate and the renderer live on one object, so a name
the dialect reports as supported always has a rendering; a provider that can express only part of
the family answers Supports(string) per name, and a provider that can express none returns
null from ScalarFunctions.
public interface IScalarFunctions- Extension Methods
Remarks
Unlike the stateless IIifRenderer/ILimitByRenderer, this object carries
both the per-name predicate and the renderer, hence the plural capability-noun name rather than the
*Renderer suffix.
Methods
GetUnsupportedReason(string)
The reason the scalar function name is unavailable on this dialect's
declared state (for example a function that requires a later server version), or
null when the name is supported, is unknown to the dialect, or the dialect
has no version-specific answer. The caller shows this reason instead of its generic "not
supported" message, so a version-gated name fails closed with the required and the declared
version. Declared as a default interface method returning null so an external
IScalarFunctions written before the member existed keeps its previous behaviour.
string? GetUnsupportedReason(string name)Parameters
namestringThe CLR method name of the CommonFunctions member.
Returns
Render(string, IReadOnlyList<string>)
Renders the scalar function name over the already-rendered
args. name is the CLR method name of the
CommonFunctions member (for example lpad, concat_ws).
string Render(string name, IReadOnlyList<string> args)Parameters
namestringargsIReadOnlyList<string>
Returns
Supports(string)
True when the scalar function name can be rendered.
bool Supports(string name)Parameters
namestring