DISTINCT may not be ignored inside a UNION ALL common table expression.

Fix for ticket [c51489c3b8f919c5]

FossilOrigin-Name: 7d2b590d3abd66a7e6ae9046198eb669e0fd2f223f7691281e9ad795a12b8903

diff --git a/manifest b/manifest
index 069f1645cd1f9834bb1d29aea5fa4e4f5ce68b0c..278b587ac8ab15b7f31f99ca66c3cd6d1ee9b612 100644 (file)
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Fix\sa\spair\sof\sassert()s\sin\s"PRAGMA\sforeign_key_check"\sthat\smight\shave\sgiven\na\sfalse-positive\sfollowing\san\sOOM.
-D 2020-09-16T19:48:23.775
+C DISTINCT\smay\snot\sbe\signored\sinside\sa\sUNION\sALL\scommon\stable\sexpression.\nFix\sfor\sticket\s[c51489c3b8f919c5]
+D 2020-09-17T00:46:09.055
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -535,12 +535,12 @@ F src/printf.c 30e92b638fac71dcd85cdea1d12ecfae354c9adee2c71e8e1ae4727cde7c91ed
 F src/random.c 80f5d666f23feb3e6665a6ce04c7197212a88384
 F src/resolve.c 97b91fb25d86881ff20c9ad2ad98412c6c1bb5f7d6c9bb044db250cbc9cfcd4b
 F src/rowset.c ba9515a922af32abe1f7d39406b9d35730ed65efab9443dc5702693b60854c92
-F src/select.c 233e884d7da6601486c7b93aedb97fd29302ae5c03742d0e0eccb4790638bb77
+F src/select.c 6c3f7d60295f06ce7fa128bb23b1159648f0aa96a78c257af35dfef727ac63f1
 F src/shell.c.in 0fd9eca42731d94a293d7b12a76c6614976f8bdbb2874768ad2e6ddbb86dffd8
 F src/sqlite.h.in 11896ccb28f85b0aa52f0d4169aaca0ed7cf3f9b3e0c544aecee0032ae2b3c2e
 F src/sqlite3.rc 5121c9e10c3964d5755191c80dd1180c122fc3a8
 F src/sqlite3ext.h 2d1af80082edffd71c6f96f70ad1ce6a4fb46615ad10291fc77fe0dea9ff0197
-F src/sqliteInt.h d8d69318b1ba3906d4860da1cd1c6b3650b81c9595e5bc360c6469a1e54e09e1
+F src/sqliteInt.h 34319c13e900063b267052168b277c7bc1e124a1ceef457e450d53ce618bb96e
 F src/sqliteLimit.h d7323ffea5208c6af2734574bae933ca8ed2ab728083caa117c9738581a31657
 F src/status.c 4b8bc2a6905163a38b739854a35b826c737333fab5b1f8e03fa7eb9a4799c4c1
 F src/table.c 0f141b58a16de7e2fbe81c308379e7279f4c6b50eb08efeec5892794a0ba30d1
@@ -1759,7 +1759,7 @@ F test/windowB.test 7a983ea1cc1cf72be7f378e4b32f6cb2d73014c5cd8b25aaee825164cd42
 F test/windowerr.tcl f5acd6fbc210d7b5546c0e879d157888455cd4a17a1d3f28f07c1c8a387019e0
 F test/windowerr.test a8b752402109c15aa1c5efe1b93ccb0ce1ef84fa964ae1cd6684dd0b3cc1819b
 F test/windowfault.test 72375ae71031eabf96bc88d0af128c8628a091ddc99b5a394e848b3df5fc17ad
-F test/with1.test 584580a5ae79868a91873863f8cb2d00040006dc1e4c332ef1d8642f2815dc6e
+F test/with1.test 323659eaf309787add657d05e5943e437a7a3494f2b6602a0deb18fdebc1ab4c
 F test/with2.test e0030e2f0267a910d6c0e4f46f2dfe941c1cc0d4f659ba69b3597728e7e8f1ab
 F test/with3.test 13b3336739da648a9e4dfa11bb04e73a920c97620041007c5f75d5d14084c346
 F test/with4.test 257be66c0c67fee1defbbac0f685c3465e2cad037f21ce65f23f86084f198205
@@ -1880,7 +1880,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 6c94ba4b1c16b676978808dcb24f63c2f22915af5dcfe9f635c037011affcf4b
-R 38e8b34a5e2ff3cf94eaf76807abdad3
+P 9ea3039b538ffd0f348c8fbc9452af1fbf899a1f668af9a2404bdd0f8dd21351
+R 5bf1eaed1b0f62e19f1e327d7467bbe1
 U drh
-Z 188d1d8f2a6059fab39eb41cb4a67396
+Z 6e1d5387493b3a726ae70a6af2467d64

diff --git a/manifest.uuid b/manifest.uuid
index bce527ad9fed076b16b48e2e809af22765e71ccd..22a693b7d86dfc084b80023f834e16de7cf81488 100644 (file)
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-9ea3039b538ffd0f348c8fbc9452af1fbf899a1f668af9a2404bdd0f8dd21351
\ No newline at end of file
+7d2b590d3abd66a7e6ae9046198eb669e0fd2f223f7691281e9ad795a12b8903
\ No newline at end of file

diff --git a/src/select.c b/src/select.c
index 9568dbadc9ed5ef04a30ea30fe62dbeab71ba0ce..535f883a176781c66063a52ca906da1be049be56 100644 (file)
--- a/src/select.c
+++ b/src/select.c
@@ -5808,13 +5808,11 @@ int sqlite3Select(
   assert( p->pOrderBy==0 || pDest->eDest!=SRT_Fifo );
   assert( p->pOrderBy==0 || pDest->eDest!=SRT_DistQueue );
   assert( p->pOrderBy==0 || pDest->eDest!=SRT_Queue );
-  if( IgnorableOrderby(pDest) ){
-    assert(pDest->eDest==SRT_Exists || pDest->eDest==SRT_Union || 
-           pDest->eDest==SRT_Except || pDest->eDest==SRT_Discard ||
-           pDest->eDest==SRT_Queue  || pDest->eDest==SRT_DistFifo ||
-           pDest->eDest==SRT_DistQueue || pDest->eDest==SRT_Fifo);
-    /* If ORDER BY makes no difference in the output then neither does
-    ** DISTINCT so it can be removed too. */
+  if( IgnorableDistinct(pDest) ){
+    assert(pDest->eDest==SRT_Exists     || pDest->eDest==SRT_Union || 
+           pDest->eDest==SRT_Except     || pDest->eDest==SRT_Discard ||
+           pDest->eDest==SRT_DistQueue  || pDest->eDest==SRT_DistFifo );
+    /* All of these destinations are also able to ignore the ORDER BY clause */
     sqlite3ExprListDelete(db, p->pOrderBy);
     p->pOrderBy = 0;
     p->selFlags &= ~SF_Distinct;

diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index 9afc287a5baf827ac3737090eae5da856579231f..ec832eca6ad048f51c2065dd8f38e1215cfd5075 100644 (file)
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -3152,9 +3152,6 @@ struct Select {
 **                     statements within triggers whose only purpose is
 **                     the side-effects of functions.
 **
-** All of the above are free to ignore their ORDER BY clause. Those that
-** follow must honor the ORDER BY clause.
-**
 **     SRT_Output      Generate a row of output (using the OP_ResultRow
 **                     opcode) for each row in the result set.
 **
@@ -3211,13 +3208,18 @@ struct Select {
 #define SRT_Except       2  /* Remove result from a UNION index */
 #define SRT_Exists       3  /* Store 1 if the result is not empty */
 #define SRT_Discard      4  /* Do not save the results anywhere */
-#define SRT_Fifo         5  /* Store result as data with an automatic rowid */
-#define SRT_DistFifo     6  /* Like SRT_Fifo, but unique results only */
+#define SRT_DistFifo     5  /* Like SRT_Fifo, but unique results only */
+#define SRT_DistQueue    6  /* Like SRT_Queue, but unique results only */
+
+/* The DISTINCT clause is ignored for all of the above.  Not that
+** IgnorableDistinct() implies IgnorableOrderby() */
+#define IgnorableDistinct(X) ((X->eDest)<=SRT_DistQueue)
+
 #define SRT_Queue        7  /* Store result in an queue */
-#define SRT_DistQueue    8  /* Like SRT_Queue, but unique results only */
+#define SRT_Fifo         8  /* Store result as data with an automatic rowid */
 
 /* The ORDER BY clause is ignored for all of the above */
-#define IgnorableOrderby(X) ((X->eDest)<=SRT_DistQueue)
+#define IgnorableOrderby(X) ((X->eDest)<=SRT_Fifo)
 
 #define SRT_Output       9  /* Output each row of result */
 #define SRT_Mem         10  /* Store result in a memory cell */

diff --git a/test/with1.test b/test/with1.test
index 66e456345c1f730461bfea1d7b2d37eef0d10d08..5386f7ddb0943b5dcdcaf5ca850b13dd3253e6c6 100644 (file)
--- a/test/with1.test
+++ b/test/with1.test
@@ -1171,4 +1171,40 @@ do_catchsql_test 26.0 {
   SELECT x,O. * O FROM i ¬I,I? 10;
 } {1 {near "O": syntax error}}
 
+# 2020-09-17 ticket c51489c3b8f919c5
+# DISTINCT cannot be ignored in a UNION ALL recursive CTE
+#
+reset_db
+do_execsql_test 26.1 {
+  CREATE TABLE t (label VARCHAR(10), step INTEGER);
+  INSERT INTO T VALUES('a', 1);
+  INSERT INTO T VALUES('a', 1);
+  INSERT INTO T VALUES('b', 1);
+  WITH RECURSIVE cte(label, step) AS (
+      SELECT DISTINCT * FROM t 
+    UNION ALL 
+      SELECT label, step + 1 FROM cte WHERE step < 3
+  )
+  SELECT * FROM cte ORDER BY +label, +step;
+} {a 1 a 2 a 3 b 1 b 2 b 3}
+do_execsql_test 26.2 {
+  WITH RECURSIVE cte(label, step) AS (
+      SELECT * FROM t 
+    UNION
+      SELECT label, step + 1 FROM cte WHERE step < 3
+  )
+  SELECT * FROM cte ORDER BY +label, +step;
+} {a 1 a 2 a 3 b 1 b 2 b 3}
+do_execsql_test 26.3 {
+  CREATE TABLE tworow(x);
+  INSERT INTO tworow(x) VALUES(1),(2);
+  DELETE FROM t WHERE rowid=2;
+  WITH RECURSIVE cte(label, step) AS (
+      SELECT * FROM t
+    UNION ALL
+      SELECT DISTINCT label, step + 1 FROM cte, tworow WHERE step < 3
+  )
+  SELECT * FROM cte ORDER BY +label, +step;
+} {a 1 a 2 a 3 b 1 b 2 b 3}
+
 finish_test