Add SQLITE_DBCONFIG_REVERSE_SCANORDER for direct C-language access to the

"PRAGMA reverse_unordered_selects" setting.

FossilOrigin-Name: 83e84531b46814aea6dad1ce8283cb9f6b90ad52badb60b875ea8f66e4ac0925

3 files changed, 18 insertions, 4 deletions

diff --git a/src/main.c b/src/main.c
index 23010d5fc..3f03a5c1e 100644
--- a/src/main.c
+++ b/src/main.c
@@ -971,6 +971,7 @@ int sqlite3_db_config(sqlite3 *db, int op, ...){
         { SQLITE_DBCONFIG_LEGACY_FILE_FORMAT,    SQLITE_LegacyFileFmt  },
         { SQLITE_DBCONFIG_TRUSTED_SCHEMA,        SQLITE_TrustedSchema  },
         { SQLITE_DBCONFIG_STMT_SCANSTATUS,       SQLITE_StmtScanStatus },
+        { SQLITE_DBCONFIG_REVERSE_SCANORDER,     SQLITE_ReverseOrder   },
       };
       unsigned int i;
       rc = SQLITE_ERROR; /* IMP: R-42790-23372 */
diff --git a/src/shell.c.in b/src/shell.c.in
index 944f65562..b76e44f45 100644
--- a/src/shell.c.in
+++ b/src/shell.c.in
@@ -8169,6 +8169,8 @@ static int do_meta_command(char *zLine, ShellState *p){
         { "load_extension",     SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION },
         { "no_ckpt_on_close",   SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE      },
         { "reset_database",     SQLITE_DBCONFIG_RESET_DATABASE        },
+        { "reverse_scanorder",  SQLITE_DBCONFIG_REVERSE_SCANORDER     },
+        { "stmt_scanstatus",    SQLITE_DBCONFIG_STMT_SCANSTATUS       },
         { "trigger_eqp",        SQLITE_DBCONFIG_TRIGGER_EQP           },
         { "trusted_schema",     SQLITE_DBCONFIG_TRUSTED_SCHEMA        },
         { "writable_schema",    SQLITE_DBCONFIG_WRITABLE_SCHEMA       },
diff --git a/src/sqlite.h.in b/src/sqlite.h.in
index 9dd023821..ec63e52c7 100644
--- a/src/sqlite.h.in
+++ b/src/sqlite.h.in
@@ -2456,7 +2456,7 @@ struct sqlite3_mem_methods {
 ** not considered a bug since SQLite versions 3.3.0 and earlier do not support
 ** either generated columns or decending indexes.
 ** </dd>
-
+**
 ** [[SQLITE_DBCONFIG_STMT_SCANSTATUS]]
 ** <dt>SQLITE_DBCONFIG_STMT_SCANSTATUS</td>
 ** <dd>The SQLITE_DBCONFIG_STMT_SCANSTATUS option is only useful in
@@ -2465,7 +2465,17 @@ struct sqlite3_mem_methods {
 ** statistics. For statistics to be collected, the flag must be set on
 ** the database handle both when the SQL statement is prepared and when it 
 ** is stepped. The flag is set (collection of statistics is enabled)
-** by default.
+** by default.</dd>
+**
+** [[SQLITE_DBCONFIG_REVERSE_SCANORDER]]
+** <dt>SQLITE_DBCONFIG_REVERSE_SCANORDER</td>
+** <dd>The SQLITE_DBCONFIG_REVERSE_SCANORDER option change the default order
+** in which tables and indexes are scanned so that the scans start at the end
+** and work toward the beginning rather than starting at the beginning and
+** working toward the end.  Setting SQLITE_DBCONFIG_REVERSE_SCANORDER is the
+** same as setting [PRAGMA reverse_unordered_selects].  This configuration option
+** is useful for application testing.</dd>
+**
 ** </dl>
 */
 #define SQLITE_DBCONFIG_MAINDBNAME            1000 /* const char* */
@@ -2486,8 +2496,9 @@ struct sqlite3_mem_methods {
 #define SQLITE_DBCONFIG_ENABLE_VIEW           1015 /* int int* */
 #define SQLITE_DBCONFIG_LEGACY_FILE_FORMAT    1016 /* int int* */
 #define SQLITE_DBCONFIG_TRUSTED_SCHEMA        1017 /* int int* */
-#define SQLITE_DBCONFIG_STMT_SCANSTATUS       1018 /* int int* */
-#define SQLITE_DBCONFIG_MAX                   1018 /* Largest DBCONFIG */
+#define SQLITE_DBCONFIG_STMT_SCANSTATUS       1080 /* int int*  */
+#define SQLITE_DBCONFIG_REVERSE_SCANORDER     1019 /* int int* */
+#define SQLITE_DBCONFIG_MAX                   1019 /* Largest DBCONFIG */
 
 /*
 ** CAPI3REF: Enable Or Disable Extended Result Codes