Make the FROM clause on a SELECT optional. If omitted, the result of

the SELECT is a single row consisting of the values in the expression list. (CVS 520)

FossilOrigin-Name: 28ce42f7872e2660faa22e66b508db9b1f046af0

manifest

@@ -1,5 +1,5 @@
-C Add\san\sfflush()\scall\sto\sshell.c\sto\sinsure\sthat\sall\soutput\shas\sbeen\swritten\nbefore\swe\sprompt\sfor\sa\snew\sline\sof\sinput.\s(CVS\s519)
-D 2002-04-04T15:10:12
+C Make\sthe\sFROM\sclause\son\sa\sSELECT\soptional.\s\sIf\somitted,\sthe\sresult\sof\nthe\sSELECT\sis\sa\ssingle\srow\sconsisting\sof\sthe\svalues\sin\sthe\sexpression\slist.\s(CVS\s520)
+D 2002-04-06T13:57:43
 F Makefile.in 50f1b3351df109b5774771350d8c1b8d3640130d
 F Makefile.template 89e373b2dad0321df00400fa968dc14b61a03296
 F README a4c0ba11354ef6ba0776b400d057c59da47a4cc0
@@ -35,7 +35,7 @@ F src/os.c 5ab8b6b4590d0c1ab8e96c67996c170e4462e0fc
 F src/os.h 4a361fccfbc4e7609b3e1557f604f94c1e96ad10
 F src/pager.c f136f5ba82c896d500a10b6a2e5caea62abf716b
 F src/pager.h 6fddfddd3b73aa8abc081b973886320e3c614f0e
-F src/parse.y d63f93b67edf9e318afea87b71d69af3334a9649
+F src/parse.y 9a8a2311dd95101bb02b3991042e619eea49729a
 F src/printf.c 300a90554345751f26e1fc0c0333b90a66110a1d
 F src/random.c 19e8e00fe0df32a742f115773f57651be327cabe
 F src/select.c 92aef3f69e90dc065d680d88b1f075409e9249bb
@@ -84,7 +84,7 @@ F test/printf.test 3cb415073754cb8ff076f26173143c3cd293a9da
 F test/quick.test 6f023c7a73fc413e6d65b7a1879c79764038dc05
 F test/quote.test 286db944717afa9a9bf829dd85e59185c65d5435
 F test/rowid.test 4c55943300cddf73dd0f88d40a268cab14c83274
-F test/select1.test 114d4545c19f6cbbbcaa2a100f698757e6e36188
+F test/select1.test 734b9f45a85b4f8d594390b1ed3cbff0b8c76c84
 F test/select2.test aceea74fd895b9d007512f72499db589735bd8e4
 F test/select3.test 9469c332250a75a0ef1771fb5da62dc04ec77f18
 F test/select4.test 29a2ffb187f3d8b6ca42a0a6b619e9cabe12e228
@@ -116,7 +116,7 @@ F www/arch.fig d5f9752a4dbf242e9cfffffd3f5762b6c63b3bcf
 F www/arch.png 82ef36db1143828a7abc88b1e308a5f55d4336f4
 F www/arch.tcl 72a0c80e9054cc7025a50928d28d9c75c02c2b8b
 F www/c_interface.tcl 567cda531aac9d68a61ef02e26c6b202bd856db2
-F www/changes.tcl 4b4a3c58c29ec56c063c6f550a3aaf70ea3bb637
+F www/changes.tcl 765719e4e445b1c6b60d1d3cfeed65570cb9d877
 F www/conflict.tcl 81dd21f9a679e60aae049e9dd8ab53d59570cda2
 F www/crosscompile.tcl 3622ebbe518927a3854a12de51344673eb2dd060
 F www/download.tcl 29aa6679ca29621d10613f60ebbbda18f4b91c49
@@ -124,14 +124,14 @@ F www/dynload.tcl 02eb8273aa78cfa9070dd4501dca937fb22b466c
 F www/faq.tcl fb1e92e2f604546694f83a36d969492f52fb685d
 F www/formatchng.tcl 2ce21ff30663fad6618198fe747ce675df577590
 F www/index.tcl 2a9653ebeeaba3aca3401f476ba0e0e4acb40929
-F www/lang.tcl e6c277480c4e31877c08509af7a16f6c69bb1046
+F www/lang.tcl 52a54be934dcbc6ec314c12bcdd4cf899ca54904
 F www/mingw.tcl f1c7c0a7f53387dd9bb4f8c7e8571b7561510ebc
 F www/opcode.tcl bdec8ef9f100dbd87bbef8976c54b88e43fd8ccc
 F www/speed.tcl da8afcc1d3ccc5696cfb388a68982bc3d9f7f00f
 F www/sqlite.tcl 8b5884354cb615049aed83039f8dfe1552a44279
 F www/tclsqlite.tcl 829b393d1ab187fd7a5e978631b3429318885c49
 F www/vdbe.tcl 2013852c27a02a091d39a766bc87cff329f21218
-P c2320eabfe44d6eb05c02b76547e5bd48a29943c
-R ef6fd0215a968b215139b8a713f806b2
+P 932274187e045ce331177b1a640ed62da4a22d94
+R 3cad40d6183414669ab6e27b1970fbd2
 U drh
-Z e1fdaafdc22b731c2498d3444c88f13c
+Z b7a9666e501a84ef150d099ac582d5f8

manifest.uuid

@@ -1 +1 @@
-932274187e045ce331177b1a640ed62da4a22d94
+28ce42f7872e2660faa22e66b508db9b1f046af0

src/parse.y

@@ -14,7 +14,7 @@
 ** the parser.  Lemon will also generate a header file containing
 ** numeric codes for all of the tokens.
 **
-** @(#) $Id: parse.y,v 1.60 2002/04/04 02:10:57 drh Exp $
+** @(#) $Id: parse.y,v 1.61 2002/04/06 13:57:43 drh Exp $
 */
 %token_prefix TK_
 %token_type {Token}
@@ -271,6 +271,7 @@ as ::= AS.
 %type from {IdList*}
 %destructor from {sqliteIdListDelete($$);}
 
+from(A) ::= .                                 {A = sqliteMalloc(sizeof(*A));}
 from(A) ::= FROM seltablist(X).               {A = X;}
 stl_prefix(A) ::= seltablist(X) COMMA.        {A = X;}
 stl_prefix(A) ::= .                           {A = 0;}

test/select1.test

@@ -11,7 +11,7 @@
 # This file implements regression tests for SQLite library.  The
 # focus of this file is testing the SELECT statement.
 #
-# $Id: select1.test,v 1.23 2002/04/04 02:10:57 drh Exp $
+# $Id: select1.test,v 1.24 2002/04/06 13:57:43 drh Exp $
 
 set testdir [file dirname $argv0]
 source $testdir/tester.tcl
@@ -626,4 +626,44 @@ do_test select1-11.15 {
   }
 } {y.max(a) 3 y.max(b) 4 t3.a 1 t3.b 2}
 
+# Tests of SELECT statements without a FROM clause.
+#
+do_test select1-12.1 {
+  execsql2 {
+    SELECT 1+2+3
+  }
+} {1+2+3 6}
+do_test select1-12.2 {
+  execsql2 {
+    SELECT 1,'hello',2
+  }
+} {1 1 'hello' hello 2 2}
+do_test select1-12.3 {
+  execsql2 {
+    SELECT 1 AS 'a','hello' AS 'b',2 AS 'c'
+  }
+} {a 1 b hello c 2}
+do_test select1-12.4 {
+  execsql {
+    DELETE FROM t3;
+    INSERT INTO t3 VALUES(1,2);
+    SELECT * FROM t3 UNION SELECT 3 AS 'a', 4 ORDER BY a;
+  }
+} {1 2 3 4}
+do_test select1-12.5 {
+  execsql {
+    SELECT 3, 4 UNION SELECT * FROM t3;
+  }
+} {1 2 3 4}
+do_test select1-12.6 {
+  execsql {
+    SELECT * FROM t3 WHERE a=(SELECT 1);
+  }
+} {1 2}
+do_test select1-12.7 {
+  execsql {
+    SELECT * FROM t3 WHERE a=(SELECT 2);
+  }
+} {}
+
 finish_test

www/changes.tcl

@@ -28,6 +28,7 @@ proc chng {date desc} {
 chng {2002 Apr 03 (2.4.7)} {
 <li>Add the ability to put TABLE.* in the column list of a
     SELECT statement.</li>
+<li>Permit SELECT statements without a FROM clause.</li>
 }
 
 chng {2002 Apr 02 (2.4.6)} {

www/lang.tcl

@@ -1,7 +1,7 @@
 #
 # Run this Tcl script to generate the sqlite.html file.
 #
-set rcsid {$Id: lang.tcl,v 1.29 2002/03/28 14:20:08 drh Exp $}
+set rcsid {$Id: lang.tcl,v 1.30 2002/04/06 13:57:44 drh Exp $}
 
 puts {<html>
 <head>
@@ -955,7 +955,7 @@ information.</p>
 Section SELECT select
 
 Syntax {sql-statement} {
-SELECT <result> FROM <table-list>
+SELECT <result> [FROM <table-list>]
 [WHERE <expression>]
 [GROUP BY <expr-list>]
 [HAVING <expression>]
@@ -993,6 +993,8 @@ puts {for that one expression.</p>
 the FROM keyword.  If more than one table is specified, then the
 query is against the (inner) join of the various tables.  A sub-query
 in parentheses may be substituted for any table name in the FROM clause.
+The entire FROM clause may be omitted, in which case the result is a
+single row consisting of the values of the expression list.
 </p>
 
 <p>The WHERE clause can be used to limit the number of rows over