Parser, SQL: (0.4) TRANSACTION support in queries

Syntax extension: TIMESTAMP/TRANSACTION keyword can be used before FROM ... TO, BETWEEN ... AND.
Example:
    SELECT * FROM t1 FOR SYSTEM_TIME TIMESTAMP FROM '1-1-1' TO NOW();

Closes #27

sql/share/errmsg-utf8.txt

@@ -7537,3 +7537,9 @@ ER_SYS_END_FIELD_MUST_BE_BIGINT
 
 ER_NO_VERSIONED_FIELDS_IN_VERSIONED_TABLE
         eng "Every field specified unversioned in versioned table"
+
+ER_VERS_TRX_ID_UNSUPPORTED
+        eng "Engine does not support versioned TRX_ID"
+
+ER_VERS_RANGE_UNITS_MISMATCH
+        eng "Range units mismatch"

sql/sql_lex.cc

@@ -33,9 +33,9 @@
 #include "sql_signal.h"
 
 
-void LEX::parse_error()
+void LEX::parse_error(uint err_number)
 {
-  thd->parse_error();
+  thd->parse_error(err_number);
 }
 
 

sql/sql_lex.h

@@ -2649,7 +2649,6 @@ struct LEX: public Query_tables_list
 private:
   Query_arena_memroot *arena_for_set_stmt;
   MEM_ROOT *mem_root_for_set_stmt;
-  void parse_error();
   bool sp_block_finalize(THD *thd, const Lex_spblock_st spblock,
                                    class sp_label **splabel);
   bool sp_change_context(THD *thd, const sp_pcontext *ctx, bool exclusive);
@@ -2663,6 +2662,7 @@ private:
   bool sp_for_loop_increment(THD *thd, const Lex_for_loop_st &loop);
 
 public:
+  void parse_error(uint err_number= ER_SYNTAX_ERROR);
   inline bool is_arena_for_set_stmt() {return arena_for_set_stmt != 0;}
   bool set_arena_for_set_stmt(Query_arena *backup);
   void reset_arena_for_set_stmt(Query_arena *backup);

sql/sql_select.cc

@@ -668,7 +668,7 @@ setup_without_group(THD *thd, Ref_ptr_array ref_pointer_array,
 }
 
 static int
-setup_for_system_time(THD *thd, TABLE_LIST *tables, COND **where_expr, SELECT_LEX *select_lex)
+setup_for_system_time(THD *thd, TABLE_LIST *tables, COND **where_expr, SELECT_LEX *slex)
 {
   DBUG_ENTER("setup_for_system_time");
 
@@ -698,11 +698,11 @@ setup_for_system_time(THD *thd, TABLE_LIST *tables, COND **where_expr, SELECT_LE
      because they must outlive execution phase for multiple executions. */
   arena= thd->activate_stmt_arena_if_needed(&backup);
 
-  if (select_lex->saved_where)
+  if (slex->saved_where)
   {
     DBUG_ASSERT(thd->stmt_arena->is_sp_execute());
     /* 2. this copy_andor_structure() is also required by the same reason */
-    *where_expr= select_lex->saved_where->copy_andor_structure(thd);
+    *where_expr= slex->saved_where->copy_andor_structure(thd);
   }
   else if (thd->stmt_arena->is_sp_execute())
   {
@@ -711,7 +711,7 @@ setup_for_system_time(THD *thd, TABLE_LIST *tables, COND **where_expr, SELECT_LE
     else if (*where_expr) // SP executed first time (STMT_INITIALIZED_FOR_SP)
       /* 1. copy_andor_structure() is required since this andor tree
          is modified later (and on shorter arena) */
-      select_lex->saved_where= (*where_expr)->copy_andor_structure(thd);
+      slex->saved_where= (*where_expr)->copy_andor_structure(thd);
   }
 
   /* We have to save also non-versioned on_expr since we may have
@@ -754,15 +754,23 @@ setup_for_system_time(THD *thd, TABLE_LIST *tables, COND **where_expr, SELECT_LE
       Field *fstart= table->table->vers_start_field();
       Field *fend= table->table->vers_end_field();
 
-      DBUG_ASSERT(select_lex->parent_lex);
+      DBUG_ASSERT(slex->parent_lex);
-      Name_resolution_context *context= select_lex->parent_lex->current_context();
+      Name_resolution_context *context= slex->parent_lex->current_context();
       DBUG_ASSERT(context);
 
       Item *row_start= new (thd->mem_root) Item_field(thd, context, fstart);
       Item *row_end= new (thd->mem_root) Item_field(thd, context, fend);
       Item *row_end2= row_end;
 
-      if (!table->table->versioned_by_sql())
+      if (table->table->versioned_by_sql())
+      {
+        if (slex->vers_conditions.unit == UNIT_TRX_ID)
+        {
+          my_error(ER_VERS_TRX_ID_UNSUPPORTED, MYF(0), table->table_name);
+          DBUG_RETURN(-1);
+        }
+      }
+      else if (slex->vers_conditions.unit == UNIT_TIMESTAMP)
       {
         DBUG_ASSERT(table->table->s && table->table->s->db_plugin);
         row_start= new (thd->mem_root) Item_func_vtq_ts(
@@ -778,7 +786,7 @@ setup_for_system_time(THD *thd, TABLE_LIST *tables, COND **where_expr, SELECT_LE
       }
 
       Item *cond1= 0, *cond2= 0, *curr= 0;
-      switch (select_lex->vers_conditions.type)
+      switch (slex->vers_conditions.type)
       {
         case FOR_SYSTEM_TIME_UNSPECIFIED:
           if (table->table->versioned_by_sql())
@@ -796,21 +804,21 @@ setup_for_system_time(THD *thd, TABLE_LIST *tables, COND **where_expr, SELECT_LE
           break;
         case FOR_SYSTEM_TIME_AS_OF:
           cond1= new (thd->mem_root) Item_func_le(thd, row_start,
-            select_lex->vers_conditions.start);
+            slex->vers_conditions.start);
           cond2= new (thd->mem_root) Item_func_gt(thd, row_end,
-            select_lex->vers_conditions.start);
+            slex->vers_conditions.start);
           break;
         case FOR_SYSTEM_TIME_FROM_TO:
           cond1= new (thd->mem_root) Item_func_lt(thd, row_start,
-                                                  select_lex->vers_conditions.end);
+                                                  slex->vers_conditions.end);
           cond2= new (thd->mem_root) Item_func_ge(thd, row_end,
-                                                  select_lex->vers_conditions.start);
+                                                  slex->vers_conditions.start);
           break;
         case FOR_SYSTEM_TIME_BETWEEN:
           cond1= new (thd->mem_root) Item_func_le(thd, row_start,
-                                                  select_lex->vers_conditions.end);
+                                                  slex->vers_conditions.end);
           cond2= new (thd->mem_root) Item_func_ge(thd, row_end,
-                                                  select_lex->vers_conditions.start);
+                                                  slex->vers_conditions.start);
           break;
         default:
           DBUG_ASSERT(0);

sql/sql_yacc.yy

@@ -849,6 +849,7 @@ Virtual_column_info *add_virtual_expression(THD *thd, Item *expr)
   enum Window_frame::Frame_exclusion frame_exclusion;
   enum trigger_order_type trigger_action_order_type;
   DDL_options_st object_ddl_options;
+  enum vers_range_unit_t vers_range_unit;
 }
 
 %{
@@ -1968,6 +1969,8 @@ END_OF_INPUT
 
 %type <lex_str_list> opt_with_column_list
 
+%type <vers_range_unit> trans_or_timestamp
+
 %%
 
 
@@ -8673,14 +8676,25 @@ select_options:
           }
         ;
 
+trans_or_timestamp:
+          TRANSACTION_SYM
+          {
+            $$ = UNIT_TRX_ID;
+          }
+        | TIMESTAMP
+          {
+            $$ = UNIT_TIMESTAMP;
+          }
+        ;
+
 opt_for_system_time_clause:
           /* empty */
           {}
         | FOR_SYSTEM_TIME_SYM
           AS OF_SYM
-          TIMESTAMP simple_expr
+          trans_or_timestamp simple_expr
           {
-            Lex->current_select->vers_conditions.init(FOR_SYSTEM_TIME_AS_OF, $5);
+            Lex->current_select->vers_conditions.init(FOR_SYSTEM_TIME_AS_OF, $4, $5);
           }
         | FOR_SYSTEM_TIME_SYM
           AS OF_SYM
@@ -8689,23 +8703,55 @@ opt_for_system_time_clause:
             Item *item= new (thd->mem_root) Item_func_now_local(thd, 6);
             if (item == NULL)
               MYSQL_YYABORT;
-            Lex->current_select->vers_conditions.init(FOR_SYSTEM_TIME_AS_OF, item);
+            Lex->current_select->vers_conditions.init(FOR_SYSTEM_TIME_AS_OF, UNIT_TIMESTAMP, item);
           }
         | FOR_SYSTEM_TIME_SYM
           FROM
-          TIMESTAMP simple_expr
+          trans_or_timestamp
+          simple_expr
           TO_SYM
-          TIMESTAMP simple_expr
+          trans_or_timestamp
+          simple_expr
           {
-            Lex->current_select->vers_conditions.init(FOR_SYSTEM_TIME_FROM_TO, $4, $7);
+            if ($3 != $6)
+            {
+              Lex->parse_error(ER_VERS_RANGE_UNITS_MISMATCH);
+              MYSQL_YYABORT;
+            }
+            Lex->current_select->vers_conditions.init(FOR_SYSTEM_TIME_FROM_TO, $3, $4, $7);
+          }
+        | FOR_SYSTEM_TIME_SYM
+          trans_or_timestamp
+          FROM
+          simple_expr
+          TO_SYM
+          simple_expr
+          {
+            Lex->current_select->vers_conditions.init(FOR_SYSTEM_TIME_FROM_TO, $2, $4, $6);
           }
         | FOR_SYSTEM_TIME_SYM
           BETWEEN_SYM
-          TIMESTAMP simple_expr
+          trans_or_timestamp
+          simple_expr
           AND_SYM
-          TIMESTAMP simple_expr
+          trans_or_timestamp
+          simple_expr
           {
-            Lex->current_select->vers_conditions.init(FOR_SYSTEM_TIME_BETWEEN, $4, $7);
+            if ($3 != $6)
+            {
+              Lex->parse_error(ER_VERS_RANGE_UNITS_MISMATCH);
+              MYSQL_YYABORT;
+            }
+            Lex->current_select->vers_conditions.init(FOR_SYSTEM_TIME_BETWEEN, $3, $4, $7);
+          }
+        | FOR_SYSTEM_TIME_SYM
+          trans_or_timestamp
+          BETWEEN_SYM
+          simple_expr
+          AND_SYM
+          simple_expr
+          {
+            Lex->current_select->vers_conditions.init(FOR_SYSTEM_TIME_BETWEEN, $2, $4, $6);
           }
         ;
 

sql/table.h

@@ -1812,7 +1812,7 @@ class Item_in_subselect;
   4) jtbm semi-join (jtbm_subselect != NULL)
 */
 
-enum for_system_time_type
+enum vers_range_type_t
 {
   FOR_SYSTEM_TIME_UNSPECIFIED = 0,
   FOR_SYSTEM_TIME_AS_OF,
@@ -1820,24 +1820,34 @@ enum for_system_time_type
   FOR_SYSTEM_TIME_BETWEEN
 };
 
+enum vers_range_unit_t
+{
+  UNIT_TIMESTAMP = 0,
+  UNIT_TRX_ID
+};
+
 /** System versioning support. */
 struct vers_select_conds_t
 {
-  enum for_system_time_type type;
+  vers_range_type_t type;
+  vers_range_unit_t unit;
   Item *start, *end;
 
   void empty()
   {
     type= FOR_SYSTEM_TIME_UNSPECIFIED;
+    unit= UNIT_TIMESTAMP;
     start= end= NULL;
   }
 
   void init(
-    const enum for_system_time_type t,
+    vers_range_type_t t,
-    Item * const s,
+    vers_range_unit_t u,
-    Item * const e= NULL)
+    Item * s,
+    Item * e= NULL)
   {
     type= t;
+    unit= u;
     start= s;
     end= e;
   }