diff options
Diffstat (limited to 'sql/table.cc')
| -rw-r--r-- | sql/table.cc | 577 |
1 files changed, 568 insertions, 9 deletions
diff --git a/sql/table.cc b/sql/table.cc index edf671b5a3b..003cab73a3d 100644 --- a/sql/table.cc +++ b/sql/table.cc @@ -33,6 +33,12 @@ LEX_STRING GENERAL_LOG_NAME= {C_STRING_WITH_LEN("general_log")}; /* SLOW_LOG name */ LEX_STRING SLOW_LOG_NAME= {C_STRING_WITH_LEN("slow_log")}; +/* + Keyword added as a prefix when parsing the defining expression for a + virtual column read from the column definition saved in the frm file +*/ +LEX_STRING parse_vcol_keyword= { C_STRING_WITH_LEN("PARSE_VCOL_EXPR ") }; + /* Functions defined in this file */ void open_table_error(TABLE_SHARE *share, int error, int db_errno, @@ -663,10 +669,11 @@ static int open_binary_frm(THD *thd, TABLE_SHARE *share, uchar *head, uint interval_count, interval_parts, read_length, int_length; uint db_create_options, keys, key_parts, n_length; uint key_info_length, com_length, null_bit_pos; + uint vcol_screen_length; uint extra_rec_buf_length; uint i,j; bool use_hash; - char *keynames, *names, *comment_pos; + char *keynames, *names, *comment_pos, *vcol_screen_pos; uchar *record; uchar *disk_buff, *strpos, *null_flags, *null_pos; ulong pos, record_offset, *rec_per_key, rec_buff_length; @@ -836,6 +843,7 @@ static int open_binary_frm(THD *thd, TABLE_SHARE *share, uchar *head, strpos+= (strmov(keynames, (char *) strpos) - keynames)+1; share->reclength = uint2korr((head+16)); + share->stored_rec_length= share->reclength; if (*(head+26) == 1) share->system= 1; /* one-record-database */ #ifdef HAVE_CRYPTED_FRM @@ -1040,24 +1048,28 @@ static int open_binary_frm(THD *thd, TABLE_SHARE *share, uchar *head, int_length= uint2korr(head+274); share->null_fields= uint2korr(head+282); com_length= uint2korr(head+284); + vcol_screen_length= uint2korr(head+286); + share->vfields= 0; + share->stored_fields= share->fields; share->comment.length= (int) (head[46]); share->comment.str= strmake_root(&share->mem_root, (char*) head+47, share->comment.length); - DBUG_PRINT("info",("i_count: %d i_parts: %d index: %d n_length: %d int_length: %d com_length: %d", interval_count,interval_parts, share->keys,n_length,int_length, com_length)); - + DBUG_PRINT("info",("i_count: %d i_parts: %d index: %d n_length: %d int_length: %d com_length: %d vcol_screen_length: %d", interval_count,interval_parts, share->keys,n_length,int_length, com_length, vcol_screen_length)); if (!(field_ptr = (Field **) alloc_root(&share->mem_root, (uint) ((share->fields+1)*sizeof(Field*)+ interval_count*sizeof(TYPELIB)+ (share->fields+interval_parts+ keys+3)*sizeof(char *)+ - (n_length+int_length+com_length))))) + (n_length+int_length+com_length+ + vcol_screen_length))))) goto err; /* purecov: inspected */ share->field= field_ptr; read_length=(uint) (share->fields * field_pack_length + - pos+ (uint) (n_length+int_length+com_length)); + pos+ (uint) (n_length+int_length+com_length+ + vcol_screen_length)); if (read_string(file,(uchar**) &disk_buff,read_length)) goto err; /* purecov: inspected */ #ifdef HAVE_CRYPTED_FRM @@ -1078,7 +1090,11 @@ static int open_binary_frm(THD *thd, TABLE_SHARE *share, uchar *head, memcpy((char*) names, strpos+(share->fields*field_pack_length), (uint) (n_length+int_length)); comment_pos= names+(n_length+int_length); - memcpy(comment_pos, disk_buff+read_length-com_length, com_length); + memcpy(comment_pos, disk_buff+read_length-com_length-vcol_screen_length, + com_length); + vcol_screen_pos= names+(n_length+int_length+com_length); + memcpy(vcol_screen_pos, disk_buff+read_length-vcol_screen_length, + vcol_screen_length); fix_type_pointers(&interval_array, &share->fieldnames, 1, &names); if (share->fieldnames.count != share->fields) @@ -1146,10 +1162,14 @@ static int open_binary_frm(THD *thd, TABLE_SHARE *share, uchar *head, for (i=0 ; i < share->fields; i++, strpos+=field_pack_length, field_ptr++) { uint pack_flag, interval_nr, unireg_type, recpos, field_length; + uint vcol_info_length=0; + uint vcol_expr_length=0; enum_field_types field_type; CHARSET_INFO *charset=NULL; Field::geometry_type geom_type= Field::GEOM_GEOMETRY; LEX_STRING comment; + Virtual_column_info *vcol_info= 0; + bool fld_stored_in_db= TRUE; if (new_frm_ver >= 3) { @@ -1184,6 +1204,18 @@ static int open_binary_frm(THD *thd, TABLE_SHARE *share, uchar *head, goto err; } } + + if ((uchar)field_type == (uchar)MYSQL_TYPE_VIRTUAL) + { + DBUG_ASSERT(interval_nr); // Expect non-null expression + /* + The interval_id byte in the .frm file stores the length of the + expression statement for a virtual column. + */ + vcol_info_length= interval_nr; + interval_nr= 0; + } + if (!comment_length) { comment.str= (char*) ""; @@ -1195,6 +1227,34 @@ static int open_binary_frm(THD *thd, TABLE_SHARE *share, uchar *head, comment.length= comment_length; comment_pos+= comment_length; } + + if (vcol_info_length) + { + /* + Get virtual column data stored in the .frm file as follows: + byte 1 = 1 (always 1 to allow for future extensions) + byte 2 = sql_type + byte 3 = flags (as of now, 0 - no flags, 1 - field is physically stored) + byte 4-... = virtual column expression (text data) + */ + vcol_info= new Virtual_column_info(); + if ((uint)vcol_screen_pos[0] != 1) + { + error= 4; + goto err; + } + field_type= (enum_field_types) (uchar) vcol_screen_pos[1]; + fld_stored_in_db= (bool) (uint) vcol_screen_pos[2]; + vcol_expr_length= vcol_info_length-(uint)FRM_VCOL_HEADER_SIZE; + if (!(vcol_info->expr_str.str= + (char *)memdup_root(&share->mem_root, + vcol_screen_pos+(uint)FRM_VCOL_HEADER_SIZE, + vcol_expr_length))) + goto err; + vcol_info->expr_str.length= vcol_expr_length; + vcol_screen_pos+= vcol_info_length; + share->vfields++; + } } else { @@ -1285,6 +1345,8 @@ static int open_binary_frm(THD *thd, TABLE_SHARE *share, uchar *head, reg_field->field_index= i; reg_field->comment=comment; + reg_field->vcol_info= vcol_info; + reg_field->stored_in_db= fld_stored_in_db; if (field_type == MYSQL_TYPE_BIT && !f_bit_as_char(pack_flag)) { if ((null_bit_pos+= field_length & 7) > 7) @@ -1309,8 +1371,17 @@ static int open_binary_frm(THD *thd, TABLE_SHARE *share, uchar *head, if (use_hash) (void) my_hash_insert(&share->name_hash, (uchar*) field_ptr); // never fail + if (!reg_field->stored_in_db) + { + share->stored_fields--; + if (share->stored_rec_length>=recpos) + share->stored_rec_length= recpos-1; + } } *field_ptr=0; // End marker + /* Sanity checks: */ + DBUG_ASSERT(share->fields>=share->stored_fields); + DBUG_ASSERT(share->reclength>=share->stored_rec_length); /* Fix key->name and key_part->field */ if (key_parts) @@ -1597,6 +1668,297 @@ static int open_binary_frm(THD *thd, TABLE_SHARE *share, uchar *head, DBUG_RETURN(error); } /* open_binary_frm */ +/* + @brief + Clear GET_FIXED_FIELDS_FLAG in all fields of a table + + @param + table The table for whose fields the flags are to be cleared + + @note + This routine is used for error handling purposes. + + @return + none +*/ + +static void clear_field_flag(TABLE *table) +{ + Field **ptr; + DBUG_ENTER("clear_field_flag"); + + for (ptr= table->field; *ptr; ptr++) + (*ptr)->flags&= (~GET_FIXED_FIELDS_FLAG); + DBUG_VOID_RETURN; +} + + +/* + @brief + Perform semantic analysis of the defining expression for a virtual column + + @param + thd The thread object + @param + table The table containing the virtual column + @param + vcol_field The virtual field whose defining expression is to be analyzed + + @details + The function performs semantic analysis of the defining expression for + the virtual column vcol_field. The expression is used to compute the + values of this column. + + @note + The function exploits the fact that the fix_fields method sets the flag + GET_FIXED_FIELDS_FLAG for all fields in the item tree. + This flag must always be unset before returning from this function + since it is used for other purposes as well. + + @retval + TRUE An error occurred, something was wrong with the function + @retval + FALSE Otherwise +*/ + +bool fix_vcol_expr(THD *thd, + TABLE *table, + Field *vcol_field) +{ + Virtual_column_info *vcol_info= vcol_field->vcol_info; + Item* func_expr= vcol_info->expr_item; + uint dir_length, home_dir_length; + bool result= TRUE; + TABLE_LIST tables; + TABLE_LIST *save_table_list, *save_first_table, *save_last_table; + int error; + Name_resolution_context *context; + const char *save_where; + char* db_name; + char db_name_string[FN_REFLEN]; + bool save_use_only_table_context; + Field **ptr, *field; + enum_mark_columns save_mark_used_columns= thd->mark_used_columns; + DBUG_ASSERT(func_expr); + DBUG_ENTER("fix_vcol_expr"); + + /* + Set-up the TABLE_LIST object to be a list with a single table + Set the object to zero to create NULL pointers and set alias + and real name to table name and get database name from file name. + */ + + bzero((void*)&tables, sizeof(TABLE_LIST)); + tables.alias= tables.table_name= (char*) table->s->table_name.str; + tables.table= table; + tables.next_local= 0; + tables.next_name_resolution_table= 0; + strmov(db_name_string, table->s->normalized_path.str); + dir_length= dirname_length(db_name_string); + db_name_string[dir_length - 1]= 0; + home_dir_length= dirname_length(db_name_string); + db_name= &db_name_string[home_dir_length]; + tables.db= db_name; + + thd->mark_used_columns= MARK_COLUMNS_NONE; + + context= thd->lex->current_context(); + table->map= 1; //To ensure correct calculation of const item + table->get_fields_in_item_tree= TRUE; + save_table_list= context->table_list; + save_first_table= context->first_name_resolution_table; + save_last_table= context->last_name_resolution_table; + context->table_list= &tables; + context->first_name_resolution_table= &tables; + context->last_name_resolution_table= NULL; + func_expr->walk(&Item::change_context_processor, 0, (uchar*) context); + save_where= thd->where; + thd->where= "virtual column function"; + + /* Save the context before fixing the fields*/ + save_use_only_table_context= thd->lex->use_only_table_context; + thd->lex->use_only_table_context= TRUE; + /* Fix fields referenced to by the virtual column function */ + error= func_expr->fix_fields(thd, (Item**)0); + /* Restore the original context*/ + thd->lex->use_only_table_context= save_use_only_table_context; + context->table_list= save_table_list; + context->first_name_resolution_table= save_first_table; + context->last_name_resolution_table= save_last_table; + + if (unlikely(error)) + { + DBUG_PRINT("info", + ("Field in virtual column expression does not belong to the table")); + goto end; + } + thd->where= save_where; +#ifdef PARANOID + /* + Walk through the Item tree checking if all items are valid + to be part of the virtual column + */ + error= func_expr->walk(&Item::check_vcol_func_processor, 0, NULL); + if (error) + { + my_error(ER_VIRTUAL_COLUMN_FUNCTION_IS_NOT_ALLOWED, MYF(0), field_name); + goto end; + } +#endif + if (unlikely(func_expr->const_item())) + { + my_error(ER_CONST_EXPR_IN_VCOL, MYF(0)); + goto end; + } + /* Ensure that this virtual column is not based on another virtual field. */ + ptr= table->field; + while ((field= *(ptr++))) + { + if ((field->flags & GET_FIXED_FIELDS_FLAG) && + (field->vcol_info)) + { + my_error(ER_VCOL_BASED_ON_VCOL, MYF(0)); + goto end; + } + } + result= FALSE; + +end: + + /* Clear GET_FIXED_FIELDS_FLAG for the fields of the table */ + clear_field_flag(table); + + table->get_fields_in_item_tree= FALSE; + thd->mark_used_columns= save_mark_used_columns; + table->map= 0; //Restore old value + + DBUG_RETURN(result); +} + +/* + @brief + Unpack the definition of a virtual column from its linear representation + + @parm + thd The thread object + @param + table The table containing the virtual column + @param + field The field for the virtual + @param + vcol_expr The string representation of the defining expression + @param[out] + error_reported The flag to inform the caller that no other error + messages are to be generated + + @details + The function takes string representation 'vcol_expr' of the defining + expression for the virtual field 'field' of the table 'table' and + parses it, building an item object for it. The pointer to this item is + placed into in field->vcol_info.expr_item. After this the function performs + semantic analysis of the item by calling the the function fix_vcol_expr. + Since the defining expression is part of the table definition the item + for it is created in table->memroot within a separate Query_arena. + The free_list of this arena is saved in field->vcol_info.item_free_list + to be freed when the table defition is removed from the TABLE_SHARE cache. + + @note + Before passing 'vcol_expr" to the parser the function embraces it in + parenthesis and prepands it a special keyword. + + @retval + FALSE If a success + @retval + TRUE Otherwise +*/ +bool unpack_vcol_info_from_frm(THD *thd, + TABLE *table, + Field *field, + LEX_STRING *vcol_expr, + bool *error_reported) +{ + bool rc= FALSE; + DBUG_ENTER("unpack_vcol_info_from_frm"); + DBUG_ASSERT(vcol_expr); + + /* + Step 1: Construct the input string for the parser. + The string to be parsed has to be of the following format: + "PARSE_VCOL_EXPR (<expr_string_from_frm>)". + */ + char *vcol_expr_str; + int str_len= 0; + CHARSET_INFO *old_character_set_client; + + if (!(vcol_expr_str= (char*) alloc_root(&table->mem_root, + vcol_expr->length + + parse_vcol_keyword.length + 3))) + { + DBUG_RETURN(TRUE); + } + memcpy(vcol_expr_str, + (char*) parse_vcol_keyword.str, + parse_vcol_keyword.length); + str_len= parse_vcol_keyword.length; + memcpy(vcol_expr_str + str_len, "(", 1); + str_len++; + memcpy(vcol_expr_str + str_len, + (char*) vcol_expr->str, + vcol_expr->length); + str_len+= vcol_expr->length; + memcpy(vcol_expr_str + str_len, ")", 1); + str_len++; + memcpy(vcol_expr_str + str_len, "\0", 1); + str_len++; + Parser_state parser_state(thd, vcol_expr_str, str_len); + + /* + Step 2: Setup thd for parsing. + */ + Query_arena *backup_stmt_arena_ptr= thd->stmt_arena; + Query_arena backup_arena; + Query_arena vcol_arena(&table->mem_root, Query_arena::INITIALIZED); + thd->set_n_backup_active_arena(&vcol_arena, &backup_arena); + thd->stmt_arena= &vcol_arena; + + thd->lex->parse_vcol_expr= TRUE; + old_character_set_client= thd->variables.character_set_client; + + /* + Step 3: Use the parser to build an Item object from vcol_expr_str. + */ + if (parse_sql(thd, &parser_state, NULL)) + { + goto err; + } + /* From now on use vcol_info generated by the parser. */ + field->vcol_info= thd->lex->vcol_info; + + /* Validate the Item tree. */ + if (fix_vcol_expr(thd, table, field)) + { + *error_reported= TRUE; + field->vcol_info= 0; + goto err; + } + field->vcol_info->item_free_list= thd->free_list; + goto end; + +err: + rc= TRUE; + thd->lex->parse_vcol_expr= FALSE; + thd->free_items(); +end: + thd->stmt_arena= backup_stmt_arena_ptr; + thd->restore_active_arena(&vcol_arena, &backup_arena); + thd->variables.character_set_client= old_character_set_client; + + DBUG_RETURN(rc); +} + +/* + Read data from a binary .frm file from MySQL 3.23 - 5.0 into TABLE_SHARE +*/ /* Open a table based on a TABLE_SHARE @@ -1631,7 +1993,7 @@ int open_table_from_share(THD *thd, TABLE_SHARE *share, const char *alias, uint records, i, bitmap_size; bool error_reported= FALSE; uchar *record, *bitmaps; - Field **field_ptr; + Field **field_ptr, **vfield_ptr; DBUG_ENTER("open_table_from_share"); DBUG_PRINT("enter",("name: '%s.%s' form: 0x%lx", share->db.str, share->table_name.str, (long) outparam)); @@ -1785,6 +2147,34 @@ int open_table_from_share(THD *thd, TABLE_SHARE *share, const char *alias, } } + /* + Process virtual columns, if any. + */ + if (!(vfield_ptr = (Field **) alloc_root(&outparam->mem_root, + (uint) ((share->vfields+1)* + sizeof(Field*))))) + goto err; + + outparam->vfield= vfield_ptr; + + for (field_ptr= outparam->field; *field_ptr; field_ptr++) + { + if ((*field_ptr)->vcol_info) + { + if (unpack_vcol_info_from_frm(thd, + outparam, + *field_ptr, + &(*field_ptr)->vcol_info->expr_str, + &error_reported)) + { + error= 4; // in case no error is reported + goto err; + } + *(vfield_ptr++)= *field_ptr; + } + } + *vfield_ptr= 0; // End marker + #ifdef WITH_PARTITION_STORAGE_ENGINE if (share->partition_info_len && outparam->file) { @@ -1852,10 +2242,24 @@ partititon_err: } #endif + /* Check virtual columns against table's storage engine. */ + if (share->vfields && + ((outparam->file && + !outparam->file->check_if_supported_virtual_columns()) || + (!outparam->file && share->db_type() && + share->db_type()->db_type == DB_TYPE_CSV_DB))) // Workaround for CSV + { + my_error(ER_UNSUPPORTED_ACTION_ON_VIRTUAL_COLUMN, + MYF(0), + "Specified storage engine"); + error_reported= TRUE; + goto err; + } + /* Allocate bitmaps */ bitmap_size= share->column_bitmap_size; - if (!(bitmaps= (uchar*) alloc_root(&outparam->mem_root, bitmap_size*3))) + if (!(bitmaps= (uchar*) alloc_root(&outparam->mem_root, bitmap_size*4))) goto err; bitmap_init(&outparam->def_read_set, (my_bitmap_map*) bitmaps, share->fields, FALSE); @@ -1863,6 +2267,8 @@ partititon_err: (my_bitmap_map*) (bitmaps+bitmap_size), share->fields, FALSE); bitmap_init(&outparam->tmp_set, (my_bitmap_map*) (bitmaps+bitmap_size*2), share->fields, FALSE); + bitmap_init(&outparam->vcol_set, + (my_bitmap_map*) (bitmaps+bitmap_size*3), share->fields, FALSE); outparam->default_column_bitmaps(); /* The table struct is now initialized; Open the table */ @@ -1966,7 +2372,11 @@ int closefrm(register TABLE *table, bool free_share) if (table->field) { for (Field **ptr=table->field ; *ptr ; ptr++) + { + if ((*ptr)->vcol_info) + free_items((*ptr)->vcol_info->item_free_list); delete *ptr; + } table->field= 0; } delete table->file; @@ -4302,6 +4712,7 @@ void st_table::clear_column_bitmaps() bitmap_clear_all(&table->def_write_set); */ bzero((char*) def_read_set.bitmap, s->column_bitmap_size*2); + bzero((char*) def_read_set.bitmap, s->column_bitmap_size*4); column_bitmaps_set(&def_read_set, &def_write_set); } @@ -4387,7 +4798,14 @@ void st_table::mark_columns_used_by_index_no_reset(uint index, KEY_PART_INFO *key_part_end= (key_part + key_info[index].key_parts); for (;key_part != key_part_end; key_part++) + { bitmap_set_bit(bitmap, key_part->fieldnr-1); + if (key_part->field->vcol_info && + key_part->field->vcol_info->expr_item) + key_part->field->vcol_info-> + expr_item->walk(&Item::register_field_in_bitmap, + 1, (uchar *) bitmap); + } } @@ -4514,6 +4932,8 @@ void st_table::mark_columns_needed_for_update() file->column_bitmaps_signal(); } } + /* Mark all virtual columns needed for update */ + mark_virtual_columns_for_write(); DBUG_VOID_RETURN; } @@ -4540,9 +4960,100 @@ void st_table::mark_columns_needed_for_insert() } if (found_next_number_field) mark_auto_increment_column(); + /* Mark virtual columns for insert */ + mark_virtual_columns_for_write(); +} + + +/* + @brief Mark a column as virtual used by the query + + @param field the field for the column to be marked + + @details + The function marks the column for 'field' as virtual (computed) + in the bitmap vcol_set. + If the column is marked for the first time the expression to compute + the column is traversed and all columns that are occurred there are + marked in the read_set of the table. + + @retval + TRUE if column is marked for the first time + @retval + FALSE otherwise +*/ + +bool st_table::mark_virtual_col(Field *field) +{ + bool res; + DBUG_ASSERT(field->vcol_info); + if (!(res= bitmap_fast_test_and_set(&vcol_set, field->field_index))) + { + Item *vcol_item= field->vcol_info->expr_item; + DBUG_ASSERT(vcol_item); + vcol_item->walk(&Item::register_field_in_read_map, 1, (uchar *) 0); + } + return res; } +/* + @brief Mark virtual columns for update/insert commands + + @details + The function marks virtual columns used in a update/insert commands + in the vcol_set bitmap. + If a virtual column is from write_set it is always marked in vcol_set. + If a stored virtual column is not from write_set but it is computed + through columns from write_set it is also marked in vcol_set, and, + besides, it is added to write_set. + + @return void + + @note + Let table t1 have columns a,b,c and let column c be a stored virtual + column computed through columns a and b. Then for the query + UPDATE t1 SET a=1 + column c will be placed into vcol_set and into write_set while + column b will be placed into read_set. + If column c was a virtual column, but not a stored virtual column + then it would not be added to any of the sets. Column b would not + be added to read_set either. +*/ + +void st_table::mark_virtual_columns_for_write(void) +{ + Field **vfield_ptr, *tmp_vfield; + bool bitmap_updated= FALSE; + + for (vfield_ptr= vfield; *vfield_ptr; vfield_ptr++) + { + tmp_vfield= *vfield_ptr; + if (bitmap_is_set(write_set, tmp_vfield->field_index)) + bitmap_updated= mark_virtual_col(tmp_vfield); + else if (tmp_vfield->stored_in_db) + { + MY_BITMAP *save_read_set; + Item *vcol_item= tmp_vfield->vcol_info->expr_item; + DBUG_ASSERT(vcol_item); + bitmap_clear_all(&tmp_set); + save_read_set= read_set; + read_set= &tmp_set; + vcol_item->walk(&Item::register_field_in_read_map, 1, (uchar *) 0); + read_set= save_read_set; + bitmap_intersect(&tmp_set, write_set); + if (!bitmap_is_clear_all(&tmp_set)) + { + bitmap_set_bit(write_set, tmp_vfield->field_index); + mark_virtual_col(tmp_vfield); + bitmap_updated= TRUE; + } + } + } + if (bitmap_updated) + file->column_bitmaps_signal(); +} + /** @brief Check if this is part of a MERGE table with attached children. @@ -4550,7 +5061,7 @@ void st_table::mark_columns_needed_for_insert() @retval TRUE children are attached @retval FALSE no MERGE part or children not attached - @detail + @details A MERGE table consists of a parent TABLE and zero or more child TABLEs. Each of these TABLEs is called a part of a MERGE table. */ @@ -4796,6 +5307,54 @@ size_t max_row_length(TABLE *table, const uchar *data) return length; } +/* + @brief Compute values for virtual columns used in query + + @param table The TABLE object + @param for_write Requests to compute only fields needed for write + + @details + The function computes the values of the virtual columns of the table and + stores them in the table record buffer. + Only fields from vcol_set are computed, and, when the flag for_write is not + set to TRUE, a virtual field is computed only if it's not stored. + The flag for_write is set to TRUE for row insert/update operations. + + @retval + 0 Success + @retval + >0 Error occurred when storing a virtual field value +*/ + +int update_virtual_fields(TABLE *table, bool for_write) +{ + DBUG_ENTER("update_virtual_fields"); + Field **vfield_ptr, *vfield; + int error= 0; + if (!table || !table->vfield) + DBUG_RETURN(0); + + /* Iterate over virtual fields in the table */ + for (vfield_ptr= table->vfield; *vfield_ptr; vfield_ptr++) + { + vfield= (*vfield_ptr); + DBUG_ASSERT(vfield->vcol_info && vfield->vcol_info->expr_item); + /* Only update those fields that are marked in the vcol_set bitmap */ + if (bitmap_is_set(&table->vcol_set, vfield->field_index) && + (for_write || !vfield->stored_in_db)) + { + /* Compute the actual value of the virtual fields */ + error= vfield->vcol_info->expr_item->save_in_field(vfield, 0); + DBUG_PRINT("info", ("field '%s' - updated", vfield->field_name)); + } + else + { + DBUG_PRINT("info", ("field '%s' - skipped", vfield->field_name)); + } + } + DBUG_RETURN(0); +} + /***************************************************************************** ** Instansiate templates *****************************************************************************/ |