From d3fcd8d4c0e0425433924987afbd5b43bec8e93e Mon Sep 17 00:00:00 2001
From: unknown <monty@mysql.com>
Date: Wed, 12 May 2004 00:29:52 +0300
Subject: Don't automaticly generate a new key for a foreign key constraint if
 there is already a usable key. Prefer not automatic keys before automatic
 keys. If there is two conf

BitKeeper/etc/ignore:
  added *.d
include/my_base.h:
  Added flag for automaticly generated key
mysql-test/r/constraints.result:
  Update tests after bug fix
mysql-test/r/create.result:
  Update tests after bug fix
mysql-test/r/innodb.result:
  Added test of automatic creation of foreign keys
mysql-test/t/innodb.test:
  Added test of automatic creation of foreign keys
mysql-test/t/key_cache.test:
  Portability fixes (64 BIT os)
sql/sql_acl.cc:
  Indentation fixes
sql/sql_class.cc:
  Fix key comparison to handle prefix and optionally key segments in different order.
sql/sql_class.h:
  Added flag for automaticly generated keys
sql/sql_parse.cc:
  Added flag for automaticly generated keys
sql/sql_table.cc:
  Don't automaticly generate a new key for a foreign key constraint if there is already a usable key.
  Prefer not automatic keys before automatic keys. If there is two conflicting automatic keys, prefer the longer one.
sql/sql_yacc.yy:
  Added flag for automaticly generated keys
strings/strings-x86.s:
  Portability fix.
---
 sql/sql_table.cc | 39 ++++++++++++++++++++++++++++-----------
 1 file changed, 28 insertions(+), 11 deletions(-)

(limited to 'sql/sql_table.cc')

diff --git a/sql/sql_table.cc b/sql/sql_table.cc
index 55b726293c2..b90ff942cc6 100644
--- a/sql/sql_table.cc
+++ b/sql/sql_table.cc
@@ -679,14 +679,27 @@ int mysql_prepare_table(THD *thd, HA_CREATE_INFO *create_info,
       DBUG_RETURN(-1);
     }
     key_iterator2.rewind ();
-    while ((key2 = key_iterator2++) != key)
+    if (key->type != Key::FOREIGN_KEY)
     {
-      if (*key == *key2)
+      while ((key2 = key_iterator2++) != key)
       {
-	/* TO DO: issue warning message */
-	/* mark that the key should be ignored */
-	key->name=ignore_key;
-	break;
+        if ((key2->type != Key::FOREIGN_KEY && !foreign_key_prefix(key, key2)))
+        {
+          /* TO DO: issue warning message */
+          /* mark that the generated key should be ignored */
+          if (!key2->generated ||
+              (key->generated && key->columns.elements <
+               key2->columns.elements))
+            key->name= ignore_key;
+          else
+          {
+            /* Remove the previous, generated key */
+            key2->name= ignore_key;
+            key_parts-= key2->columns.elements;
+            (*key_count)--;
+          }
+          break;
+        }
       }
     }
     if (key->name != ignore_key)
@@ -731,14 +744,14 @@ int mysql_prepare_table(THD *thd, HA_CREATE_INFO *create_info,
 
     switch(key->type){
     case Key::MULTIPLE:
-	key_info->flags = 0;
+	key_info->flags= 0;
 	break;
     case Key::FULLTEXT:
-	key_info->flags = HA_FULLTEXT;
+	key_info->flags= HA_FULLTEXT;
 	break;
     case Key::SPATIAL:
 #ifdef HAVE_SPATIAL
-	key_info->flags = HA_SPATIAL;
+	key_info->flags= HA_SPATIAL;
 	break;
 #else
 	my_printf_error(ER_FEATURE_DISABLED,ER(ER_FEATURE_DISABLED),MYF(0),
@@ -749,8 +762,11 @@ int mysql_prepare_table(THD *thd, HA_CREATE_INFO *create_info,
       key_number--;				// Skip this key
       continue;
     default:
-	key_info->flags = HA_NOSAME;
+      key_info->flags = HA_NOSAME;
+      break;
     }
+    if (key->generated)
+      key_info->flags|= HA_GENERATED_KEY;
 
     key_info->key_parts=(uint8) key->columns.elements;
     key_info->key_part=key_part_info;
@@ -774,7 +790,7 @@ int mysql_prepare_table(THD *thd, HA_CREATE_INFO *create_info,
     */
 
     /* TODO: Add proper checks if handler supports key_type and algorithm */
-    if (key_info->flags == HA_SPATIAL)
+    if (key_info->flags & HA_SPATIAL)
     {
       if (key_info->key_parts != 1)
       {
@@ -2824,6 +2840,7 @@ int mysql_alter_table(THD *thd,char *new_db, char *new_name,
 				   Key::FULLTEXT : Key::MULTIPLE)),
 				 key_name,
 				 key_info->algorithm,
+                                 test(key_info->flags & HA_GENERATED_KEY),
 				 key_parts));
   }
   {
-- 
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