MDEV-12833 Split Column_definition::create_length_to_internal_length() to virtual methods in Type_handler

sql/field.cc

@@ -9805,61 +9805,6 @@ void Column_definition::create_length_to_internal_length_newdecimal()
 }
 
 
-/**
-  Convert create_field::length from number of characters to number of bytes.
-*/
-
-void Column_definition::create_length_to_internal_length(void)
-{
-  switch (real_field_type()) {
-  case MYSQL_TYPE_TINY_BLOB:
-  case MYSQL_TYPE_MEDIUM_BLOB:
-  case MYSQL_TYPE_LONG_BLOB:
-  case MYSQL_TYPE_BLOB:
-  case MYSQL_TYPE_GEOMETRY:
-  case MYSQL_TYPE_VAR_STRING:
-  case MYSQL_TYPE_STRING:
-  case MYSQL_TYPE_VARCHAR:
-    create_length_to_internal_length_string();
-    break;
-  case MYSQL_TYPE_ENUM:
-  case MYSQL_TYPE_SET:
-    create_length_to_internal_length_typelib();
-    break;
-  case MYSQL_TYPE_BIT:
-    create_length_to_internal_length_bit();
-    break;
-  case MYSQL_TYPE_NEWDECIMAL:
-    create_length_to_internal_length_newdecimal();
-    break;
-
-  case MYSQL_TYPE_NULL:
-    create_length_to_internal_length_null();
-    break;
-
-  case MYSQL_TYPE_DECIMAL:
-  case MYSQL_TYPE_TINY:
-  case MYSQL_TYPE_SHORT:
-  case MYSQL_TYPE_INT24:
-  case MYSQL_TYPE_LONG:
-  case MYSQL_TYPE_LONGLONG:
-  case MYSQL_TYPE_YEAR:
-  case MYSQL_TYPE_FLOAT:
-  case MYSQL_TYPE_DOUBLE:
-  case MYSQL_TYPE_TIME:
-  case MYSQL_TYPE_TIME2:
-  case MYSQL_TYPE_DATE:
-  case MYSQL_TYPE_NEWDATE:
-  case MYSQL_TYPE_DATETIME:
-  case MYSQL_TYPE_DATETIME2:
-  case MYSQL_TYPE_TIMESTAMP:
-  case MYSQL_TYPE_TIMESTAMP2:
-    create_length_to_internal_length_simple();
-    break;
-  }
-}
-
-
 bool check_expression(Virtual_column_info *vcol, LEX_CSTRING *name,
                       enum_vcol_info_type type)
 
@@ -10496,6 +10441,33 @@ Column_definition::Column_definition(THD *thd, Field *old_field,
 }
 
 
+/**
+  The common part for data type redefinition:
+    CREATE TABLE t1 (a INT) AS SELECT a FROM t2;
+  See Type_handler::Column_definition_redefine_stage1()
+  for data type specific code.
+*/
+void
+Column_definition::redefine_stage1_common(const Column_definition *dup_field,
+                                          const handler *file,
+                                          const Schema_specification_st *schema)
+{
+  set_handler(dup_field->type_handler());
+  default_value= dup_field->default_value;
+  charset=       dup_field->charset ? dup_field->charset :
+                                      schema->default_table_charset;
+  length=       dup_field->char_length;
+  pack_length=  dup_field->pack_length;
+  key_length=   dup_field->key_length;
+  decimals=     dup_field->decimals;
+  unireg_check= dup_field->unireg_check;
+  flags=        dup_field->flags;
+  interval=     dup_field->interval;
+  vcol_info=    dup_field->vcol_info;
+}
+
+
+
 /**
   maximum possible character length for blob.
   

sql/field.h

@@ -3887,7 +3887,6 @@ public:
   }
   Column_definition(THD *thd, Field *field, Field *orig_field);
   void set_attributes(const Lex_field_type_st &type, CHARSET_INFO *cs);
-  void create_length_to_internal_length(void);
   void create_length_to_internal_length_null()
   {
     DBUG_ASSERT(length == 0);
@@ -3955,6 +3954,16 @@ public:
   bool prepare_stage1_bit(THD *thd, MEM_ROOT *mem_root,
                           handler *file, ulonglong table_flags);
 
+  void redefine_stage1_common(const Column_definition *dup_field,
+                              const handler *file,
+                              const Schema_specification_st *schema);
+  bool redefine_stage1(const Column_definition *dup_field, const handler *file,
+                       const Schema_specification_st *schema)
+  {
+    const Type_handler *handler= dup_field->type_handler();
+    return handler->Column_definition_redefine_stage1(this, dup_field,
+                                                      file, schema);
+  }
   bool prepare_stage2(handler *handler, ulonglong table_flags);
   bool prepare_stage2_blob(handler *handler,
                            ulonglong table_flags, uint field_flags);

sql/sql_table.cc

@@ -3355,30 +3355,6 @@ mysql_prepare_create_table(THD *thd, HA_CREATE_INFO *create_info,
               file->ha_table_flags() & HA_CAN_BIT_FIELD)
             total_uneven_bit_length-= sql_field->length & 7;
 
-	  sql_field->default_value=	dup_field->default_value;
-	  sql_field->set_handler(dup_field->type_handler());
-
-          /*
-            If we are replacing a field with a BIT field, we need
-            to initialize pack_flag. Note that we do not need to
-            increment total_uneven_bit_length here as this dup_field
-            has already been processed.
-          */
-          if (sql_field->real_field_type() == MYSQL_TYPE_BIT)
-          {
-            sql_field->pack_flag= FIELDFLAG_NUMBER;
-            if (!(file->ha_table_flags() & HA_CAN_BIT_FIELD))
-              sql_field->pack_flag|= FIELDFLAG_TREAT_BIT_AS_CHAR;
-          }
-
-	  sql_field->charset=		(dup_field->charset ?
-					 dup_field->charset :
-					 create_info->default_table_charset);
-	  sql_field->length=		dup_field->char_length;
-          sql_field->pack_length=	dup_field->pack_length;
-          sql_field->key_length=	dup_field->key_length;
-	  sql_field->decimals=		dup_field->decimals;
-	  sql_field->unireg_check=	dup_field->unireg_check;
           /* 
             We're making one field from two, the result field will have
             dup_field->flags as flags. If we've incremented null_fields
@@ -3386,10 +3362,10 @@ mysql_prepare_create_table(THD *thd, HA_CREATE_INFO *create_info,
           */
           if (!(sql_field->flags & NOT_NULL_FLAG))
             null_fields--;
-	  sql_field->flags=		dup_field->flags;
-	  sql_field->create_length_to_internal_length();
-          sql_field->interval=          dup_field->interval;
-          sql_field->vcol_info=         dup_field->vcol_info;
+
+          if (sql_field->redefine_stage1(dup_field, file, create_info))
+            DBUG_RETURN(true);
+
 	  it2.remove();			// Remove first (create) definition
 	  select_field_pos--;
 	  break;

sql/sql_type.cc

@@ -1634,6 +1634,93 @@ bool Type_handler_geometry::
 #endif
 
 
+/*************************************************************************/
+
+bool Type_handler::
+       Column_definition_redefine_stage1(Column_definition *def,
+                                         const Column_definition *dup,
+                                         const handler *file,
+                                         const Schema_specification_st *schema)
+                                         const
+{
+  def->redefine_stage1_common(dup, file, schema);
+  def->create_length_to_internal_length_simple();
+  return false;
+}
+
+
+bool Type_handler_null::
+       Column_definition_redefine_stage1(Column_definition *def,
+                                         const Column_definition *dup,
+                                         const handler *file,
+                                         const Schema_specification_st *schema)
+                                         const
+{
+  def->redefine_stage1_common(dup, file, schema);
+  def->create_length_to_internal_length_null();
+  return false;
+}
+
+
+bool Type_handler_newdecimal::
+       Column_definition_redefine_stage1(Column_definition *def,
+                                         const Column_definition *dup,
+                                         const handler *file,
+                                         const Schema_specification_st *schema)
+                                         const
+{
+  def->redefine_stage1_common(dup, file, schema);
+  def->create_length_to_internal_length_newdecimal();
+  return false;
+}
+
+
+bool Type_handler_string_result::
+       Column_definition_redefine_stage1(Column_definition *def,
+                                         const Column_definition *dup,
+                                         const handler *file,
+                                         const Schema_specification_st *schema)
+                                         const
+{
+  def->redefine_stage1_common(dup, file, schema);
+  def->create_length_to_internal_length_string();
+  return false;
+}
+
+
+bool Type_handler_typelib::
+       Column_definition_redefine_stage1(Column_definition *def,
+                                         const Column_definition *dup,
+                                         const handler *file,
+                                         const Schema_specification_st *schema)
+                                         const
+{
+  def->redefine_stage1_common(dup, file, schema);
+  def->create_length_to_internal_length_typelib();
+  return false;
+}
+
+
+bool Type_handler_bit::
+       Column_definition_redefine_stage1(Column_definition *def,
+                                         const Column_definition *dup,
+                                         const handler *file,
+                                         const Schema_specification_st *schema)
+                                         const
+{
+  def->redefine_stage1_common(dup, file, schema);
+  /*
+    If we are replacing a field with a BIT field, we need
+    to initialize pack_flag.
+  */
+  def->pack_flag= FIELDFLAG_NUMBER;
+  if (!(file->ha_table_flags() & HA_CAN_BIT_FIELD))
+    def->pack_flag|= FIELDFLAG_TREAT_BIT_AS_CHAR;
+  def->create_length_to_internal_length_bit();
+  return false;
+}
+
+
 /*************************************************************************/
 
 bool Type_handler::

sql/sql_type.h

@@ -68,6 +68,7 @@ class Arg_comparator;
 struct st_value;
 class Protocol;
 class handler;
+struct Schema_specification_st;
 struct TABLE;
 struct SORT_FIELD_ATTR;
 
@@ -707,6 +708,28 @@ public:
                                                 Column_definition *c,
                                                 handler *file,
                                                 ulonglong table_flags) const;
+  /*
+    This method is called on queries like:
+      CREATE TABLE t2 (a INT) AS SELECT a FROM t1;
+    I.e. column "a" is queried from another table,
+    but its data type is redefined.
+    @param OUT def   - The column definition to be redefined
+    @param IN  dup   - The column definition to take the data type from
+                       (i.e. "a INT" in the above example).
+    @param IN file   - Table owner handler. If it does not support certain
+                       data types, some conversion can be applied.
+                       I.g. true BIT to BIT-AS-CHAR.
+    @param IN schema - the owner schema definition, e.g. for the default
+                       character set and collation.
+    @retval true     - on error
+    @retval false    - on success
+  */
+  virtual bool Column_definition_redefine_stage1(Column_definition *def,
+                                                 const Column_definition *dup,
+                                                 const handler *file,
+                                                 const Schema_specification_st *
+                                                       schema)
+                                                 const;
   virtual bool Column_definition_prepare_stage2(Column_definition *c,
                                                 handler *file,
                                                 ulonglong table_flags) const= 0;
@@ -966,6 +989,15 @@ public:
     DBUG_ASSERT(0);
     return true;
   }
+  bool Column_definition_redefine_stage1(Column_definition *def,
+                                         const Column_definition *dup,
+                                         const handler *file,
+                                         const Schema_specification_st *schema)
+                                         const
+  {
+    DBUG_ASSERT(0);
+    return true;
+  }
   bool Column_definition_prepare_stage2(Column_definition *c,
                                         handler *file,
                                         ulonglong table_flags) const
@@ -1536,6 +1568,11 @@ public:
                                         Column_definition *c,
                                         handler *file,
                                         ulonglong table_flags) const;
+  bool Column_definition_redefine_stage1(Column_definition *def,
+                                         const Column_definition *dup,
+                                         const handler *file,
+                                         const Schema_specification_st *schema)
+                                         const;
   uint32 max_display_length(const Item *item) const;
   uint Item_time_precision(Item *item) const
   {
@@ -1830,6 +1867,11 @@ public:
                                         Column_definition *c,
                                         handler *file,
                                         ulonglong table_flags) const;
+  bool Column_definition_redefine_stage1(Column_definition *def,
+                                         const Column_definition *dup,
+                                         const handler *file,
+                                         const Schema_specification_st *schema)
+                                         const;
   bool Column_definition_prepare_stage2(Column_definition *c,
                                         handler *file,
                                         ulonglong table_flags) const;
@@ -2250,6 +2292,11 @@ public:
                                         Column_definition *c,
                                         handler *file,
                                         ulonglong table_flags) const;
+  bool Column_definition_redefine_stage1(Column_definition *def,
+                                         const Column_definition *dup,
+                                         const handler *file,
+                                         const Schema_specification_st *schema)
+                                         const;
   bool Column_definition_prepare_stage2(Column_definition *c,
                                         handler *file,
                                         ulonglong table_flags) const;
@@ -2282,6 +2329,11 @@ public:
                                         Column_definition *c,
                                         handler *file,
                                         ulonglong table_flags) const;
+  bool Column_definition_redefine_stage1(Column_definition *def,
+                                         const Column_definition *dup,
+                                         const handler *file,
+                                         const Schema_specification_st *schema)
+                                         const;
   bool Column_definition_prepare_stage2(Column_definition *c,
                                         handler *file,
                                         ulonglong table_flags) const
@@ -2573,6 +2625,11 @@ public:
                                         Column_definition *c,
                                         handler *file,
                                         ulonglong table_flags) const;
+  bool Column_definition_redefine_stage1(Column_definition *def,
+                                         const Column_definition *dup,
+                                         const handler *file,
+                                         const Schema_specification_st *schema)
+                                         const;
 };