implement show columns

(alias of 'show fields')

src/sphinxql_extra.l

@@ -80,6 +80,7 @@ FLOAT_CONSTANT      ({INT}\.{INT}?|{INT}?\.{INT}){EXPONENT}?
 "CREATE"			{ STORE_BOUNDS; return TOK_CREATE; }
 "DATABASE"			{ STORE_BOUNDS; return TOK_DATABASE; }
 "FIELDS"			{ STORE_BOUNDS; return TOK_FIELDS; }
+"COLUMNS"			{ STORE_BOUNDS; return TOK_COLUMNS; }
 "FLUSH" 			{ STORE_BOUNDS; return TOK_FLUSH; }
 "FROM"				{ STORE_BOUNDS; return TOK_FROM; }
 "GLOBAL"			{ STORE_BOUNDS; return TOK_GLOBAL; }

src/sphinxql_extra.y

@@ -24,6 +24,7 @@
 %token	TOK_QUOTED_STRING "string"
 
 %token	TOK_CREATE
+%token	TOK_COLUMNS
 %token	TOK_DATABASE
 %token	TOK_FIELDS
 %token	TOK_FLUSH
@@ -78,7 +79,7 @@ statement:
 ident:
 	TOK_FIELDS | TOK_FLUSH | TOK_FROM | TOK_LOCK | TOK_READ | TOK_RELOAD | TOK_SAVEPOINT
 	| TOK_SET | TOK_SHOW | TOK_TABLE | TOK_TABLES | TOK_UNLOCK | TOK_USE | TOK_WITH | TOK_IDENT
-	| TOK_TRIGGERS | TOK_LIKE | TOK_CREATE | TOK_DATABASE
+	| TOK_TRIGGERS | TOK_LIKE | TOK_CREATE | TOK_DATABASE | TOK_COLUMNS
 	; // no TOK_SESSION, no TOK_GLOBAL
 
 //////////////////////////////////////////////////////////////////////////
@@ -228,9 +229,12 @@ savepoint_sp:
 	;
 
 //////////////////////////////////////////////////////////////////////////
+fields_or_columns:
+	TOK_FIELDS | TOK_COLUMNS
+	;
 
 show_fields:
-	TOK_SHOW TOK_FIELDS TOK_FROM table_ident like_filter
+	TOK_SHOW fields_or_columns TOK_FROM table_ident like_filter
 		{
 			pParser->SetIndex ($4);
 			pParser->m_pStmt->m_eStmt = STMT_DESCRIBE;

test/test_272/test.xml

@@ -127,6 +127,9 @@ show fields from `check`;
 SELECT /*!40001 SQL_NO_CACHE */ * FROM `check`;
 SELECT * FROM `check`;
 
+show columns from check;
+show columns from indexrt like '%id';
+
 /*M!999999\- enable the sandbox mode */
 /*!40101 SET @OLD_CHARACTER_SET_CLIENT=@@CHARACTER_SET_CLIENT */;