MDEV-7563 Support CHECK constraint as in (or close to) SQL Standard

MDEV-10134 Add full support for DEFAULT

- Added support for using tables with MySQL 5.7 virtual fields,
  including MySQL 5.7 syntax
- Better error messages also for old cases
- CREATE ... SELECT now also updates timestamp columns
- Blob can now have default values
- Added new system variable "check_constraint_checks", to turn of
  CHECK constraint checking if needed.
- Removed some engine independent tests in suite vcol to only test myisam
- Moved some tests from 'include' to 't'. Should some day be done for all tests.
- FRM version increased to 11 if one uses virtual fields or constraints
- Changed to use a bitmap to check if a field has got a value, instead of
  setting HAS_EXPLICIT_VALUE bit in field flags
- Expressions can now be up to 65K in total
- Ensure we are not refering to uninitialized fields when handling virtual fields or defaults
- Changed check_vcol_func_processor() to return a bitmap of used types
- Had to change some functions that calculated cached value in fix_fields to do
  this in val() or getdate() instead.
- store_now_in_TIME() now takes a THD argument
- fill_record() now updates default values
- Add a lookahead for NOT NULL, to be able to handle DEFAULT 1+1 NOT NULL
- Automatically generate a name for constraints that doesn't have a name
- Added support for ALTER TABLE DROP CONSTRAINT
- Ensure that partition functions register virtual fields used. This fixes
  some bugs when using virtual fields in a partitioning function

1 files changed, 36 insertions, 27 deletions

diff --git a/sql/item_timefunc.cc b/sql/item_timefunc.cc
index 16edb35c392..69eb3d63dd8 100644
--- a/sql/item_timefunc.cc
+++ b/sql/item_timefunc.cc
@@ -1465,7 +1465,7 @@ void Item_temporal_func::fix_length_and_dec()
     We set maybe_null to 1 as default as any bad argument with date or
     time can get us to return NULL.
   */ 
-  maybe_null= 1;
+  maybe_null= (arg_count > 0);
   if (decimals)
   {
     if (decimals == NOT_FIXED_DEC)
@@ -1581,24 +1581,12 @@ bool Item_func_from_days::get_date(MYSQL_TIME *ltime, ulonglong fuzzy_date)
 }
 
 
-void Item_func_curdate::fix_length_and_dec()
-{
-  store_now_in_TIME(&ltime);
-  
-  /* We don't need to set second_part and neg because they already 0 */
-  ltime.hour= ltime.minute= ltime.second= 0;
-  ltime.time_type= MYSQL_TIMESTAMP_DATE;
-  Item_datefunc::fix_length_and_dec();
-  maybe_null= false;
-}
-
 /**
     Converts current time in my_time_t to MYSQL_TIME represenatation for local
     time zone. Defines time zone (local) used for whole CURDATE function.
 */
-void Item_func_curdate_local::store_now_in_TIME(MYSQL_TIME *now_time)
+void Item_func_curdate_local::store_now_in_TIME(THD *thd, MYSQL_TIME *now_time)
 {
-  THD *thd= current_thd;
   thd->variables.time_zone->gmt_sec_to_TIME(now_time, thd->query_start());
   thd->time_zone_used= 1;
 }
@@ -1608,9 +1596,8 @@ void Item_func_curdate_local::store_now_in_TIME(MYSQL_TIME *now_time)
     Converts current time in my_time_t to MYSQL_TIME represenatation for UTC
     time zone. Defines time zone (UTC) used for whole UTC_DATE function.
 */
-void Item_func_curdate_utc::store_now_in_TIME(MYSQL_TIME *now_time)
+void Item_func_curdate_utc::store_now_in_TIME(THD *thd, MYSQL_TIME *now_time)
 {
-  THD *thd= current_thd;
   my_tz_UTC->gmt_sec_to_TIME(now_time, thd->query_start());
   /* 
     We are not flagging this query as using time zone, since it uses fixed
@@ -1622,6 +1609,17 @@ void Item_func_curdate_utc::store_now_in_TIME(MYSQL_TIME *now_time)
 bool Item_func_curdate::get_date(MYSQL_TIME *res,
 				 ulonglong fuzzy_date __attribute__((unused)))
 {
+  THD *thd= current_thd;
+  query_id_t query_id= thd->query_id;
+  /* Cache value for this query */
+  if (last_query_id != query_id)
+  {
+    last_query_id= query_id;
+    store_now_in_TIME(thd, &ltime);
+    /* We don't need to set second_part and neg because they already 0 */
+    ltime.hour= ltime.minute= ltime.second= 0;
+    ltime.time_type= MYSQL_TIMESTAMP_DATE;
+  }
   *res=ltime;
   return 0;
 }
@@ -1641,6 +1639,14 @@ bool Item_func_curtime::fix_fields(THD *thd, Item **items)
 bool Item_func_curtime::get_date(MYSQL_TIME *res,
                                  ulonglong fuzzy_date __attribute__((unused)))
 {
+  THD *thd= current_thd;
+  query_id_t query_id= thd->query_id;
+  /* Cache value for this query */
+  if (last_query_id != query_id)
+  {
+    last_query_id= query_id;
+    store_now_in_TIME(thd, &ltime);
+  }
   *res= ltime;
   return 0;
 }
@@ -1661,9 +1667,8 @@ static void set_sec_part(ulong sec_part, MYSQL_TIME *ltime, Item *item)
     Converts current time in my_time_t to MYSQL_TIME represenatation for local
     time zone. Defines time zone (local) used for whole CURTIME function.
 */
-void Item_func_curtime_local::store_now_in_TIME(MYSQL_TIME *now_time)
+void Item_func_curtime_local::store_now_in_TIME(THD *thd, MYSQL_TIME *now_time)
 {
-  THD *thd= current_thd;
   thd->variables.time_zone->gmt_sec_to_TIME(now_time, thd->query_start());
   now_time->year= now_time->month= now_time->day= 0;
   now_time->time_type= MYSQL_TIMESTAMP_TIME;
@@ -1676,9 +1681,8 @@ void Item_func_curtime_local::store_now_in_TIME(MYSQL_TIME *now_time)
     Converts current time in my_time_t to MYSQL_TIME represenatation for UTC
     time zone. Defines time zone (UTC) used for whole UTC_TIME function.
 */
-void Item_func_curtime_utc::store_now_in_TIME(MYSQL_TIME *now_time)
+void Item_func_curtime_utc::store_now_in_TIME(THD *thd, MYSQL_TIME *now_time)
 {
-  THD *thd= current_thd;
   my_tz_UTC->gmt_sec_to_TIME(now_time, thd->query_start());
   now_time->year= now_time->month= now_time->day= 0;
   now_time->time_type= MYSQL_TIMESTAMP_TIME;
@@ -1704,9 +1708,8 @@ bool Item_func_now::fix_fields(THD *thd, Item **items)
     Converts current time in my_time_t to MYSQL_TIME represenatation for local
     time zone. Defines time zone (local) used for whole NOW function.
 */
-void Item_func_now_local::store_now_in_TIME(MYSQL_TIME *now_time)
+void Item_func_now_local::store_now_in_TIME(THD *thd, MYSQL_TIME *now_time)
 {
-  THD *thd= current_thd;
   thd->variables.time_zone->gmt_sec_to_TIME(now_time, thd->query_start());
   set_sec_part(thd->query_start_sec_part(), now_time, this);
   thd->time_zone_used= 1;
@@ -1717,9 +1720,8 @@ void Item_func_now_local::store_now_in_TIME(MYSQL_TIME *now_time)
     Converts current time in my_time_t to MYSQL_TIME represenatation for UTC
     time zone. Defines time zone (UTC) used for whole UTC_TIMESTAMP function.
 */
-void Item_func_now_utc::store_now_in_TIME(MYSQL_TIME *now_time)
+void Item_func_now_utc::store_now_in_TIME(THD *thd, MYSQL_TIME *now_time)
 {
-  THD *thd= current_thd;
   my_tz_UTC->gmt_sec_to_TIME(now_time, thd->query_start());
   set_sec_part(thd->query_start_sec_part(), now_time, this);
   /* 
@@ -1732,6 +1734,14 @@ void Item_func_now_utc::store_now_in_TIME(MYSQL_TIME *now_time)
 bool Item_func_now::get_date(MYSQL_TIME *res,
                              ulonglong fuzzy_date __attribute__((unused)))
 {
+  THD *thd= current_thd;
+  query_id_t query_id= thd->query_id;
+  /* Cache value for this query */
+  if (last_query_id != query_id)
+  {
+    last_query_id= query_id;
+    store_now_in_TIME(thd, &ltime);
+  }
   *res= ltime;
   return 0;
 }
@@ -1741,9 +1751,8 @@ bool Item_func_now::get_date(MYSQL_TIME *res,
     Converts current time in my_time_t to MYSQL_TIME represenatation for local
     time zone. Defines time zone (local) used for whole SYSDATE function.
 */
-void Item_func_sysdate_local::store_now_in_TIME(MYSQL_TIME *now_time)
+void Item_func_sysdate_local::store_now_in_TIME(THD *thd, MYSQL_TIME *now_time)
 {
-  THD *thd= current_thd;
   my_hrtime_t now= my_hrtime();
   thd->variables.time_zone->gmt_sec_to_TIME(now_time, hrtime_to_my_time(now));
   set_sec_part(hrtime_sec_part(now), now_time, this);
@@ -1754,7 +1763,7 @@ void Item_func_sysdate_local::store_now_in_TIME(MYSQL_TIME *now_time)
 bool Item_func_sysdate_local::get_date(MYSQL_TIME *res,
                                        ulonglong fuzzy_date __attribute__((unused)))
 {
-  store_now_in_TIME(res);
+  store_now_in_TIME(current_thd, res);
   return 0;
 }