IdentifierComponentRole (General SQL Parser Java Library Core 4.2.19 API)

Object
- Enum<IdentifierComponentRole>
- - gudusoft.gsqlparser.sqlenv.IdentifierComponentRole

All Implemented Interfaces:

Serializable, Comparable<IdentifierComponentRole>
```
public enum IdentifierComponentRole
extends Enum<IdentifierComponentRole>
```
The structural role one component of a qualified SQL name plays — stage S0R of docs/refactor/identifier_identity_display_separation_plan.md.
Why roles must be supplied, never inferred
A dotted name does not reveal its own shape. customer.name is table.column on most dialects and, on BigQuery, is just as likely to be base column customer plus STRUCT field name — and the two read the first component under DIFFERENT case rules, because BigQuery table names are case-sensitive while column names are not. Inferring the layout from the number of components therefore produces a confident wrong answer, which is exactly what the five existing arity-based planners in this repository do:
- SQLUtil.compareIdentifier
- IdentifierService.normalizeQualifiedName
- CatalogIdentifierPolicy.kindForSegment
- CatalogRuntime.expandCandidates
- QualifiedNameHierarchy, which this model replaces and which is deleted at the end of this stage, once the key types that supersede it exist
Where a role legitimately comes from
The AST is the authority on spelling and component boundaries; it is NOT the authority on roles. TObjectName.getTableString() returns the qualifier the user wrote, which may be an alias rather than a table, and TObjectName.columnToProperty() physically SHIFTS the tokens once the parser decides a name is column.property. So token position is syntactic and mutable. A role is established by one of:
- resolution, which knows whether a qualifier was an alias or a relation;
- a metadata importer, which already holds catalog / schema / object / column as separate fields and should pass them separately rather than joining and re-splitting them;
- a caller that states an explicit layout for a flat string it cannot avoid.
Not in this enum, on purpose
Entity kinds — table, view, package, procedure, index — are CatalogObjectKind values carried ALONGSIDE an OBJECT component, not roles of their own (named in prose, not linked: this package must not depend on the catalog layer): schema.package.procedure is two OBJECT components with different kinds, and folding kinds into roles would multiply this enum by the catalog's entity list. A routine parameter is a single-segment name scoped by its routine and keeps using CanonKey(dotParameter) in a routine-local map.
There is deliberately no generic FIELD role either: a STRUCT attribute follows identifier rules while a JSON/VARIANT key is exact data, and one role could not express both. STRUCT_FIELD covers the identifier-like case; document keys are a different component type entirely and live in the column-path key, not here.

Enum Constant Summary

Enum Constants
Enum Constant and Description
`BASE_COLUMN` The column itself — the base of any field path that follows it.
`CATALOG` A catalog / database.
`DATABASE_LINK` An Oracle-style database link.
`OBJECT` A named catalog object.
`SCHEMA` A schema.
`SERVER` A linked server, e.g.
`STRUCT_FIELD` A field of a structured type whose name follows the dialect's IDENTIFIER rules — a BigQuery STRUCT attribute, a PostgreSQL composite attribute.

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method and Description
`static IdentifierComponentRole`	`valueOf(String name)` Returns the enum constant of this type with the specified name.
`static IdentifierComponentRole[]`	`values()` Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class Enum
clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class Object
getClass, notify, notifyAll, wait, wait, wait

- Enum Constant Detail
  - SERVER
```
public static final IdentifierComponentRole SERVER
```
    A linked server, e.g. the first component of SQL Server's srv.db.dbo.t.
  - CATALOG
```
public static final IdentifierComponentRole CATALOG
```
    A catalog / database.
  - SCHEMA
```
public static final IdentifierComponentRole SCHEMA
```
    A schema.
  - OBJECT
```
public static final IdentifierComponentRole OBJECT
```
    A named catalog object. The component also carries a CatalogObjectKind, which is what distinguishes a table from a view, a package from a procedure, or an index from the table it sits on — and which is why IdentifierRolePolicy refuses to map this role: only a catalog caller knows the kind.
  - BASE_COLUMN
```
public static final IdentifierComponentRole BASE_COLUMN
```
    The column itself — the base of any field path that follows it.
  - STRUCT_FIELD
```
public static final IdentifierComponentRole STRUCT_FIELD
```
    A field of a structured type whose name follows the dialect's IDENTIFIER rules — a BigQuery STRUCT attribute, a PostgreSQL composite attribute. A document key is NOT this: see the column-path key's component kinds.
  - DATABASE_LINK
```
public static final IdentifierComponentRole DATABASE_LINK
```
    An Oracle-style database link. It is a postfix qualifier rather than a position in the dotted hierarchy, so it is stored separately from the ordered component list even though it participates in equality.
- Method Detail
  - values
```
public static IdentifierComponentRole[] values()
```
    Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:
```
for (IdentifierComponentRole c : IdentifierComponentRole.values())
    System.out.println(c);
```
    Returns:
    
    an array containing the constants of this enum type, in the order they are declared
  - valueOf
```
public static IdentifierComponentRole valueOf(String name)
```
    Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)
    
    Parameters:
    
    name - the name of the enum constant to be returned.
    
    Returns:
    
    the enum constant with the specified name
    
    Throws:
    
    IllegalArgumentException - if this enum type has no constant with the specified name
    
    NullPointerException - if the argument is null

Enum IdentifierComponentRole

Why roles must be supplied, never inferred

Where a role legitimately comes from

Not in this enum, on purpose

Enum Constant Summary

Method Summary

Methods inherited from class Enum

Methods inherited from class Object

Enum Constant Detail

SERVER

CATALOG

SCHEMA

OBJECT

BASE_COLUMN

STRUCT_FIELD

DATABASE_LINK

Method Detail

values

valueOf