diff options
Diffstat (limited to 'src/include/nodes/parsenodes.h')
| -rw-r--r-- | src/include/nodes/parsenodes.h | 47 |
1 files changed, 30 insertions, 17 deletions
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h index 6292ca237c8..7eea3175896 100644 --- a/src/include/nodes/parsenodes.h +++ b/src/include/nodes/parsenodes.h @@ -13,7 +13,7 @@ * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $PostgreSQL: pgsql/src/include/nodes/parsenodes.h,v 1.372 2008/08/28 23:09:48 tgl Exp $ + * $PostgreSQL: pgsql/src/include/nodes/parsenodes.h,v 1.373 2008/08/30 01:39:14 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -178,8 +178,10 @@ typedef struct TypeName /* * ColumnRef - specifies a reference to a column, or possibly a whole tuple * - * The "fields" list must be nonempty; its last component may be "*" - * instead of a regular field name. + * The "fields" list must be nonempty. It can contain string Value nodes + * (representing names) and A_Star nodes (representing occurrence of a '*'). + * Currently, A_Star must appear only as the last list element --- the grammar + * is responsible for enforcing this! * * Note: any array subscripting or selection of fields from composite columns * is represented by an A_Indirection node above the ColumnRef. However, @@ -189,7 +191,7 @@ typedef struct TypeName typedef struct ColumnRef { NodeTag type; - List *fields; /* field names (list of Value strings) */ + List *fields; /* field names (Value strings) or A_Star */ int location; /* token location, or -1 if unknown */ } ColumnRef; @@ -271,35 +273,46 @@ typedef struct FuncCall } FuncCall; /* - * A_Indices - array reference or bounds ([lidx:uidx] or [uidx]) + * A_Star - '*' representing all columns of a table or compound field + * + * This can appear within ColumnRef.fields, A_Indirection.indirection, and + * ResTarget.indirection lists. + */ +typedef struct A_Star +{ + NodeTag type; +} A_Star; + +/* + * A_Indices - array subscript or slice bounds ([lidx:uidx] or [uidx]) */ typedef struct A_Indices { NodeTag type; - Node *lidx; /* could be NULL */ + Node *lidx; /* NULL if it's a single subscript */ Node *uidx; } A_Indices; /* * A_Indirection - select a field and/or array element from an expression * - * The indirection list can contain both A_Indices nodes (representing - * subscripting) and string Value nodes (representing field selection - * --- the string value is the name of the field to select). For example, - * a complex selection operation like + * The indirection list can contain A_Indices nodes (representing + * subscripting), string Value nodes (representing field selection --- the + * string value is the name of the field to select), and A_Star nodes + * (representing selection of all fields of a composite type). + * For example, a complex selection operation like * (foo).field1[42][7].field2 * would be represented with a single A_Indirection node having a 4-element * indirection list. * - * Note: as of Postgres 8.0, we don't support arrays of composite values, - * so cases in which a field select follows a subscript aren't actually - * semantically legal. However the parser is prepared to handle such. + * Currently, A_Star must appear only as the last list element --- the grammar + * is responsible for enforcing this! */ typedef struct A_Indirection { NodeTag type; Node *arg; /* the thing being selected from */ - List *indirection; /* subscripts and/or field names */ + List *indirection; /* subscripts and/or field names and/or * */ } A_Indirection; /* @@ -334,7 +347,7 @@ typedef struct ResTarget { NodeTag type; char *name; /* column name or NULL */ - List *indirection; /* subscripts and field names, or NIL */ + List *indirection; /* subscripts, field names, and '*', or NIL */ Node *val; /* the value expression to compute or assign */ int location; /* token location, or -1 if unknown */ } ResTarget; @@ -1739,7 +1752,7 @@ typedef struct NotifyStmt typedef struct ListenStmt { NodeTag type; - RangeVar *relation; /* qualified name to listen on */ + RangeVar *relation; /* name to listen on */ } ListenStmt; /* ---------------------- @@ -1749,7 +1762,7 @@ typedef struct ListenStmt typedef struct UnlistenStmt { NodeTag type; - RangeVar *relation; /* qualified name to unlisten on, or '*' */ + RangeVar *relation; /* name to unlisten on, or NULL for all */ } UnlistenStmt; /* ---------------------- |