Add the experimental sqlite3_stmt_explain(S,E) interface.

FossilOrigin-Name: 5683743ddf0bb051f2fe5d137cc18407e000e77e9faa9010a22e3134b575638b

diff --git a/manifest b/manifest
index 918e28c08bd155a346ded27e213bd23864080b41..560436430f7135abe4ee31b36eceee6be768902c 100644 (file)
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Minor\sinternal\scleanups\sin\sthe\sOPFS\sVFS.
-D 2023-07-14T21:06:00.870
+C Add\sthe\sexperimental\ssqlite3_stmt_explain(S,E)\sinterface.
+D 2023-07-15T16:48:14.281
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -626,20 +626,20 @@ F src/os_win.c 7038223a1cda0a47e2ab4db47f63bf1833fe53ba0542f0f283a062ea13894103
 F src/os_win.h 7b073010f1451abe501be30d12f6bc599824944a
 F src/pager.c 5ddf3a74c633a008ea6b2f5b3186167e88e2c8ca8a252ecab06ab3f1eb48e60f
 F src/pager.h f82e9844166e1585f5786837ddc7709966138ced17f568c16af7ccf946c2baa3
-F src/parse.y 8828f9e15f04d469eab9c0f2aed504e534b1c97c68836bed6f07afab29c2ac0b
+F src/parse.y aeb7760d41cfa86465e3adba506500c021597049fd55f82a30e5b7045862c28c
 F src/pcache.c 4cd4a0043167da9ba7e19b4d179a0e6354e7fe32c16f781ecf9bf0a5ff63b40b
 F src/pcache.h 1497ce1b823cf00094bb0cf3bac37b345937e6f910890c626b16512316d3abf5
 F src/pcache1.c 602acb23c471bb8d557a6f0083cc2be641d6cafcafa19e481eba7ef4c9ca0f00
 F src/pragma.c 37b8fb02d090262280c86e1e2654bf59d8dbfbfe8dc6733f2b968a11374c095a
 F src/pragma.h e690a356c18e98414d2e870ea791c1be1545a714ba623719deb63f7f226d8bb7
-F src/prepare.c d6c4354f8ea0dc06962fbabc4b68c4471a45276a2918c929be00f9f537f69eb1
+F src/prepare.c 80548297dc0e1fb3139cdebffb5a1bcac3dfac66d791012dd74838e70445072d
 F src/printf.c 84b7b4b647f336934a5ab2e7f0c52555833cc0778d2d60e016cca52ee8c6cd8f
 F src/random.c 606b00941a1d7dd09c381d3279a058d771f406c5213c9932bbd93d5587be4b9c
 F src/resolve.c 37953a5f36c60bea413c3c04efcd433b6177009f508ef2ace0494728912fe2e9
 F src/rowset.c 8432130e6c344b3401a8874c3cb49fefe6873fec593294de077afea2dce5ec97
 F src/select.c 3ab1186290a311a8ceed1286c0e286209f7fe97b2d02c7593258004ce295dd88
-F src/shell.c.in d320d8a13636de06d777cc1eab981caca304e175464e98183cf4ea68d93db818
-F src/sqlite.h.in f999ef3642f381d69679b2516b430dbcb6c5a2a951b7f5e43dc4751b474a5774
+F src/shell.c.in 3f125426a25c717fbf8b84b3b75a8b60fa989bf7a039ed38926d455329f9dd0f
+F src/sqlite.h.in 13d5458cd23e7b4759cff4d978ad09591a457b4a2821993579953a9a4257ce0f
 F src/sqlite3.rc 5121c9e10c3964d5755191c80dd1180c122fc3a8
 F src/sqlite3ext.h da473ce2b3d0ae407a6300c4a164589b9a6bfdbec9462688a8593ff16f3bb6e4
 F src/sqliteInt.h dcb1a885e8b6cb78df618944b89d44361a99d0fe33e1bba2c150a855f7dc5599
@@ -647,7 +647,7 @@ F src/sqliteLimit.h 33b1c9baba578d34efe7dfdb43193b366111cdf41476b1e82699e14c11ee
 F src/status.c 160c445d7d28c984a0eae38c144f6419311ed3eace59b44ac6dafc20db4af749
 F src/table.c 0f141b58a16de7e2fbe81c308379e7279f4c6b50eb08efeec5892794a0ba30d1
 F src/tclsqlite.c ecbc3c99c0d0c3ed122a913f143026c26d38d57f33e06bb71185dd5c1efe37cd
-F src/test1.c 9111b12427b3b94429aff68bbcf5b125ae70438f6ce2f3f033e2a69626ec26c9
+F src/test1.c dfd07574689ee7c57af219c5f627ff32dae65dba478c124ba0359a1bde9983be
 F src/test2.c 827446e259a3b7ab949da1542953edda7b5117982576d3e6f1c24a0dd20a5cef
 F src/test3.c e5178558c41ff53236ae0271e9acb3d6885a94981d2eb939536ee6474598840e
 F src/test4.c 4533b76419e7feb41b40582554663ed3cd77aaa54e135cf76b3205098cd6e664
@@ -710,7 +710,7 @@ F src/vacuum.c 604fcdaebe76f3497c855afcbf91b8fa5046b32de3045bab89cc008d68e40104
 F src/vdbe.c 74282a947234513872a83b0bab1b8c644ece64b3e27b053ef17677c8ff9c81e0
 F src/vdbe.h 41485521f68e9437fdb7ec4a90f9d86ab294e9bb8281e33b235915e29122cfc0
 F src/vdbeInt.h 7bd49eef8f89c1a271fbf12d80a206bf56c876814c5fc6bee340f4e1907095ae
-F src/vdbeapi.c de9703f8705afc393cc2864669ce28cf9516983c8331d59aa2b978de01634365
+F src/vdbeapi.c c528ef4fafc8be172cbe4f48d8f15c9526bebde9f90185917fcc43fad264bcb6
 F src/vdbeaux.c b5e3f7e158518b4eca6f166ac43900640a3fe9735c710e12bfa119af21059339
 F src/vdbeblob.c 2516697b3ee8154eb8915f29466fb5d4f1ae39ee8b755ea909cefaf57ec5e2ce
 F src/vdbemem.c cf4a1556dd5b18c071cf7c243373c29ce752eb516022e3ad49ba72f08b785033
@@ -2043,8 +2043,11 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 816b503f093c4e6d92d0eb2f9fbd841acd01cc9bc89ee58d961b56c64f71406a
-R 6597235c929ad6ed0b90d6716177ff1b
-U stephan
-Z b7b5463364c5290e11704a96855173c7
+P 984d491eb3fe06f714bf07d6873321f3992a072812b46508e599bfefd39dff3e
+R d7676f37f2e59b0f85cc021dadb3d7bc
+T *branch * sqlite3_stmt_explain
+T *sym-sqlite3_stmt_explain *
+T -sym-trunk *
+U drh
+Z bc12630434faa3e2cbe8d73f4285c221
 # Remove this line to create a well-formed Fossil manifest.

diff --git a/manifest.uuid b/manifest.uuid
index d9fb0905d50052e4e8b0a0f685b8c44c81c25278..8363f6b5937ef67082a1704a080511fe864d5385 100644 (file)
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-984d491eb3fe06f714bf07d6873321f3992a072812b46508e599bfefd39dff3e
\ No newline at end of file
+5683743ddf0bb051f2fe5d137cc18407e000e77e9faa9010a22e3134b575638b
\ No newline at end of file

diff --git a/src/parse.y b/src/parse.y
index 6085c4bbe26d778e63bd33a56e8d7c8b09d0f779..867b62aa7ad69761c00fbfa7c7007940bdb7536c 100644 (file)
--- a/src/parse.y
+++ b/src/parse.y
@@ -148,8 +148,8 @@ ecmd ::= SEMI.
 ecmd ::= cmdx SEMI.
 %ifndef SQLITE_OMIT_EXPLAIN
 ecmd ::= explain cmdx SEMI.       {NEVER-REDUCE}
-explain ::= EXPLAIN.              { pParse->explain = 1; }
-explain ::= EXPLAIN QUERY PLAN.   { pParse->explain = 2; }
+explain ::= EXPLAIN.              { if( pParse->pReprepare==0 ) pParse->explain = 1; }
+explain ::= EXPLAIN QUERY PLAN.   { if( pParse->pReprepare==0 ) pParse->explain = 2; }
 %endif  SQLITE_OMIT_EXPLAIN
 cmdx ::= cmd.           { sqlite3FinishCoding(pParse); }
 

diff --git a/src/prepare.c b/src/prepare.c
index 39e8dcf655b854cd76752a5f277bfeb24884d83f..9f843faa860295a20cbc0114f5f73a61ed1b5d24 100644 (file)
--- a/src/prepare.c
+++ b/src/prepare.c
@@ -700,7 +700,12 @@ static int sqlite3Prepare(
   sParse.pOuterParse = db->pParse;
   db->pParse = &sParse;
   sParse.db = db;
-  sParse.pReprepare = pReprepare;
+  if( pReprepare ){
+    sParse.pReprepare = pReprepare;
+    sParse.explain = sqlite3_stmt_isexplain((sqlite3_stmt*)pReprepare);
+  }else{
+    assert( sParse.pReprepare==0 );
+  }
   assert( ppStmt && *ppStmt==0 );
   if( db->mallocFailed ){
     sqlite3ErrorMsg(&sParse, "out of memory");

diff --git a/src/shell.c.in b/src/shell.c.in
index 9165f21f71420220070274faebbb21facd12680a..ed1d8e6c4b20280f262a844d7a9cced3851c28dc 100644 (file)
--- a/src/shell.c.in
+++ b/src/shell.c.in
@@ -3453,8 +3453,6 @@ static int str_in_array(const char *zStr, const char **azArray){
 **       and "Goto" by 2 spaces.
 */
 static void explain_data_prepare(ShellState *p, sqlite3_stmt *pSql){
-  const char *zSql;               /* The text of the SQL statement */
-  const char *z;                  /* Used to check if this is an EXPLAIN */
   int *abYield = 0;               /* True if op is an OP_Yield */
   int nAlloc = 0;                 /* Allocated size of p->aiIndent[], abYield */
   int iOp;                        /* Index of operation in p->aiIndent[] */
@@ -3471,10 +3469,7 @@ static void explain_data_prepare(ShellState *p, sqlite3_stmt *pSql){
     p->cMode = p->mode;
     return;
   }
-  zSql = sqlite3_sql(pSql);
-  if( zSql==0 ) return;
-  for(z=zSql; *z==' ' || *z=='\t' || *z=='\n' || *z=='\f' || *z=='\r'; z++);
-  if( sqlite3_strnicmp(z, "explain", 7) ){
+  if( sqlite3_stmt_isexplain(pSql)!=1 ){
     p->cMode = p->mode;
     return;
   }
@@ -4332,16 +4327,15 @@ static int shell_exec(
       /* Show the EXPLAIN QUERY PLAN if .eqp is on */
       if( pArg && pArg->autoEQP && sqlite3_stmt_isexplain(pStmt)==0 ){
         sqlite3_stmt *pExplain;
-        char *zEQP;
         int triggerEQP = 0;
         disable_debug_trace_modes();
         sqlite3_db_config(db, SQLITE_DBCONFIG_TRIGGER_EQP, -1, &triggerEQP);
         if( pArg->autoEQP>=AUTOEQP_trigger ){
           sqlite3_db_config(db, SQLITE_DBCONFIG_TRIGGER_EQP, 1, 0);
         }
-        zEQP = sqlite3_mprintf("EXPLAIN QUERY PLAN %s", zStmtSql);
-        shell_check_oom(zEQP);
-        rc = sqlite3_prepare_v2(db, zEQP, -1, &pExplain, 0);
+        pExplain = pStmt;
+        sqlite3_reset(pExplain);
+        rc = sqlite3_stmt_explain(pExplain, 2);
         if( rc==SQLITE_OK ){
           while( sqlite3_step(pExplain)==SQLITE_ROW ){
             const char *zEQPLine = (const char*)sqlite3_column_text(pExplain,3);
@@ -4353,29 +4347,22 @@ static int shell_exec(
           }
           eqp_render(pArg, 0);
         }
-        sqlite3_finalize(pExplain);
-        sqlite3_free(zEQP);
         if( pArg->autoEQP>=AUTOEQP_full ){
           /* Also do an EXPLAIN for ".eqp full" mode */
-          zEQP = sqlite3_mprintf("EXPLAIN %s", zStmtSql);
-          shell_check_oom(zEQP);
-          rc = sqlite3_prepare_v2(db, zEQP, -1, &pExplain, 0);
+          sqlite3_reset(pExplain);
+          rc = sqlite3_stmt_explain(pExplain, 1);
           if( rc==SQLITE_OK ){
             pArg->cMode = MODE_Explain;
             explain_data_prepare(pArg, pExplain);
             exec_prepared_stmt(pArg, pExplain);
             explain_data_delete(pArg);
           }
-          sqlite3_finalize(pExplain);
-          sqlite3_free(zEQP);
         }
         if( pArg->autoEQP>=AUTOEQP_trigger && triggerEQP==0 ){
           sqlite3_db_config(db, SQLITE_DBCONFIG_TRIGGER_EQP, 0, 0);
-          /* Reprepare pStmt before reactivating trace modes */
-          sqlite3_finalize(pStmt);
-          sqlite3_prepare_v2(db, zSql, -1, &pStmt, 0);
-          if( pArg ) pArg->pStmt = pStmt;
         }
+        sqlite3_reset(pStmt);
+        sqlite3_stmt_explain(pStmt, 0);
         restore_debug_trace_modes();
       }
 

diff --git a/src/sqlite.h.in b/src/sqlite.h.in
index 59d9986c5210844b38b444661ef78cd3917c5b12..9e165c1e55ade89908e27eae1bd9620adfb2bd7a 100644 (file)
--- a/src/sqlite.h.in
+++ b/src/sqlite.h.in
@@ -4421,6 +4421,37 @@ int sqlite3_stmt_readonly(sqlite3_stmt *pStmt);
 */
 int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt);
 
+/*
+** CAPI3REF: Change The EXPLAIN Setting For A Prepared Statement
+** METHOD: sqlite3_stmt
+**
+** ^The sqlite3_stmt_explain(S,E) interface changes the EXPLAIN
+** setting for prepared statement S.  If E is zero, then S becomes
+** a normal prepared statement.  If E is 1, then S behaves as if
+** its SQL text began with "EXPLAIN".  If E is 2, then S behaves as if
+** its SQL text began with "EXPLAIN QUERY PLAN".
+**
+** Calling sqlite3_stmt_explain(S,E) causes prepared statement S
+** to be reprepared.  A call to sqlite3_stmt_explain(S,E) will fail
+** with SQLITE_ERROR if S cannot be re-prepared because it was created
+** using sqlite3_prepare() instead of the newer sqlite_prepare_v2() or
+** sqlite3_prepare_v3() interfaces and hence has no saved SQL text with
+** which to reprepare. Changing the explain setting for a prepared
+** statement does not change the original SQL text for the statement.
+** Hence, if the SQL text originally began with EXPLAIN or EXPLAIN
+** QUERY PLAN, but sqlite3_stmt_explain(S,0) is called to convert the
+** statement into an ordinary statement, the EXPLAIN or EXPLAIN QUERY
+** PLAN keywords still appear in the sqlite3_sql(S) output, even though
+** the statement now acts like a normal SQL statement.
+**
+** This routine returns SQLITE_OK if the explain mode is successfully
+** changed, or an error code if the explain mode could not be changed.
+** The explain mode cannot be changed while a statement is active.
+** Hence, it is good practice to call [sqlite3_reset(S)]
+** immediately prior to calling sqlite3_stmt_explain(S,E).
+*/
+int sqlite3_stmt_explain(sqlite3_stmt *pStmt, int eMode);
+
 /*
 ** CAPI3REF: Determine If A Prepared Statement Has Been Reset
 ** METHOD: sqlite3_stmt

diff --git a/src/test1.c b/src/test1.c
index adc862156f4ef5016241f502671c4eb92d4b76dc..520508d1ca6b2b3774625a70d3b2444e4bcacb34 100644 (file)
--- a/src/test1.c
+++ b/src/test1.c
@@ -2922,6 +2922,34 @@ static int SQLITE_TCLAPI test_stmt_isexplain(
   return TCL_OK;
 }
 
+/*
+** Usage:  sqlite3_stmt_explain  STMT  INT
+**
+** Set the explain to normal (0), EXPLAIN (1) or EXPLAIN QUERY PLAN (2).
+*/
+static int SQLITE_TCLAPI test_stmt_explain(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  sqlite3_stmt *pStmt;
+  int eMode = 0;
+  int rc;
+
+  if( objc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"",
+        Tcl_GetStringFromObj(objv[0], 0), " STMT INT", 0);
+    return TCL_ERROR;
+  }
+
+  if( getStmtPointer(interp, Tcl_GetString(objv[1]), &pStmt) ) return TCL_ERROR;
+  if( Tcl_GetIntFromObj(interp, objv[2], &eMode) ) return TCL_ERROR;
+  rc = sqlite3_stmt_explain(pStmt, eMode);
+  Tcl_SetObjResult(interp, Tcl_NewIntObj(rc));
+  return TCL_OK;
+}
+
 /*
 ** Usage:  sqlite3_stmt_busy  STMT
 **
@@ -8991,6 +9019,7 @@ int Sqlitetest1_Init(Tcl_Interp *interp){
      { "sqlite3_next_stmt",             test_next_stmt     ,0 },
      { "sqlite3_stmt_readonly",         test_stmt_readonly ,0 },
      { "sqlite3_stmt_isexplain",        test_stmt_isexplain,0 },
+     { "sqlite3_stmt_explain",          test_stmt_explain  ,0 },
      { "sqlite3_stmt_busy",             test_stmt_busy     ,0 },
      { "uses_stmt_journal",             uses_stmt_journal ,0 },
 

diff --git a/src/vdbeapi.c b/src/vdbeapi.c
index 920780a896563f1d68fef3c14a20d75532e6ced2..885b17f7624c94206aa0508fc29129029314a994 100644 (file)
--- a/src/vdbeapi.c
+++ b/src/vdbeapi.c
@@ -1814,6 +1814,22 @@ int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt){
   return pStmt ? ((Vdbe*)pStmt)->explain : 0;
 }
 
+/*
+** Set the explain mode for a statement.
+*/
+int sqlite3_stmt_explain(sqlite3_stmt *pStmt, int eMode){
+  Vdbe *v = (Vdbe*)pStmt;
+  int rc;
+  if( v->eVdbeState!=VDBE_READY_STATE ) return SQLITE_BUSY; 
+  if( v->explain==eMode ) return SQLITE_OK;
+  if( v->zSql==0 || eMode<0 || eMode>2 ) return SQLITE_ERROR;
+  sqlite3_mutex_enter(v->db->mutex);
+  v->explain = eMode;
+  rc = sqlite3Reprepare(v);
+  sqlite3_mutex_leave(v->db->mutex);
+  return rc;
+}
+
 /*
 ** Return true if the prepared statement is in need of being reset.
 */