MDEV-438 Microseconds: Precision is ignored in CURRENT_TIMESTAMP(N) when it is...

MDEV-438 Microseconds: Precision is ignored in CURRENT_TIMESTAMP(N) when it is given as a default column value

For MySQL 5.6 compatibility, support precision specification in CURRENT_TIMESTAMP in
a default clause, when it's not less than the column's precision.

mysql-test/r/type_timestamp_hires.result

@@ -278,3 +278,23 @@ select * from t1;
 a
 2011-01-01 01:01:01.12345
 drop table t1;
+create table t1 (a timestamp(5) default current_timestamp);
+drop table t1;
+create table t1 (a timestamp(5) default current_timestamp());
+drop table t1;
+create table t1 (a timestamp(5) default current_timestamp(2));
+ERROR 42000: Invalid default value for 'a'
+create table t1 (a timestamp(5) default current_timestamp(5));
+drop table t1;
+create table t1 (a timestamp(5) default current_timestamp(6));
+drop table t1;
+create table t1 (a timestamp(5) on update current_timestamp);
+drop table t1;
+create table t1 (a timestamp(5) on update current_timestamp());
+drop table t1;
+create table t1 (a timestamp(5) on update current_timestamp(3));
+ERROR HY000: Invalid ON UPDATE clause for 'a' column
+create table t1 (a timestamp(5) on update current_timestamp(5));
+drop table t1;
+create table t1 (a timestamp(5) on update current_timestamp(6));
+drop table t1;

mysql-test/t/type_timestamp_hires.test

@@ -14,3 +14,18 @@ insert t1 values ();
 select * from t1;
 drop table t1;
 
+#
+# MDEV-438 Microseconds: Precision is ignored in CURRENT_TIMESTAMP(N) when it is given as a default column value 
+#
+create table t1 (a timestamp(5) default current_timestamp); drop table t1;
+create table t1 (a timestamp(5) default current_timestamp()); drop table t1;
+--error ER_INVALID_DEFAULT
+create table t1 (a timestamp(5) default current_timestamp(2));
+create table t1 (a timestamp(5) default current_timestamp(5)); drop table t1;
+create table t1 (a timestamp(5) default current_timestamp(6)); drop table t1;
+create table t1 (a timestamp(5) on update current_timestamp); drop table t1;
+create table t1 (a timestamp(5) on update current_timestamp()); drop table t1;
+--error ER_INVALID_ON_UPDATE
+create table t1 (a timestamp(5) on update current_timestamp(3));
+create table t1 (a timestamp(5) on update current_timestamp(5)); drop table t1;
+create table t1 (a timestamp(5) on update current_timestamp(6)); drop table t1;

sql/sql_parse.cc

@@ -5955,6 +5955,7 @@ bool add_field_to_list(THD *thd, LEX_STRING *field_name, enum_field_types type,
 {
   register Create_field *new_field;
   LEX  *lex= thd->lex;
+  uint8 datetime_precision= length ? atoi(length) : 0;
   DBUG_ENTER("add_field_to_list");
 
   if (check_string_char_length(field_name, "", NAME_CHAR_LEN,
@@ -5994,8 +5995,10 @@ bool add_field_to_list(THD *thd, LEX_STRING *field_name, enum_field_types type,
       NOW() as default for TIMESTAMP and DATETIME type.
     */
     if (default_value->type() == Item::FUNC_ITEM && 
-        !(((Item_func*)default_value)->functype() == Item_func::NOW_FUNC &&
-          (type == MYSQL_TYPE_TIMESTAMP || type == MYSQL_TYPE_DATETIME)))
+        (static_cast<Item_func*>(default_value)->functype() !=
+         Item_func::NOW_FUNC ||
+         (mysql_type_to_time_type(type) != MYSQL_TIMESTAMP_DATETIME) ||
+         default_value->decimals < datetime_precision))
     {
       my_error(ER_INVALID_DEFAULT, MYF(0), field_name->str);
       DBUG_RETURN(1);
@@ -6018,7 +6021,8 @@ bool add_field_to_list(THD *thd, LEX_STRING *field_name, enum_field_types type,
   }
 
   if (on_update_value &&
-      !(type == MYSQL_TYPE_TIMESTAMP || type == MYSQL_TYPE_DATETIME))
+      (mysql_type_to_time_type(type) != MYSQL_TIMESTAMP_DATETIME ||
+       on_update_value->decimals < datetime_precision))
   {
     my_error(ER_INVALID_ON_UPDATE, MYF(0), field_name->str);
     DBUG_RETURN(1);

sql/sql_yacc.yy

@@ -1483,6 +1483,7 @@ bool my_yyoverflow(short **a, YYSTYPE **b, ulong *yystacksize);
         ev_alter_on_schedule_completion opt_ev_rename_to opt_ev_sql_stmt
         optional_flush_tables_arguments opt_dyncol_type dyncol_type
         opt_time_precision kill_type kill_option int_num
+        opt_default_time_precision
 
 %type <m_yes_no_unk>
         opt_chain opt_release
@@ -5898,7 +5899,7 @@ attribute:
           NULL_SYM { Lex->type&= ~ NOT_NULL_FLAG; }
         | not NULL_SYM { Lex->type|= NOT_NULL_FLAG; }
         | DEFAULT now_or_signed_literal { Lex->default_value=$2; }
-        | ON UPDATE_SYM NOW_SYM opt_time_precision
+        | ON UPDATE_SYM NOW_SYM opt_default_time_precision
           {
             Item *item= new (YYTHD->mem_root) Item_func_now_local($4);
             if (item == NULL)
@@ -5992,7 +5993,7 @@ type_with_opt_collate:
 
 
 now_or_signed_literal:
-          NOW_SYM opt_time_precision
+          NOW_SYM opt_default_time_precision
           {
             $$= new (YYTHD->mem_root) Item_func_now_local($2);
             if ($$ == NULL)
@@ -7782,6 +7783,12 @@ select_alias:
         | TEXT_STRING_sys { $$=$1; }
         ;
 
+opt_default_time_precision:
+          /* empty */             { $$= NOT_FIXED_DEC;  }
+        | '(' ')'                 { $$= NOT_FIXED_DEC;  }
+        | '(' real_ulong_num ')'  { $$= $2; };
+        ;
+
 opt_time_precision:
           /* empty */             { $$= 0;  }
         | '(' ')'                 { $$= 0;  }