集合Fields Fields集合是Field对象的集合(参看前面的“Field对象”部分)。Fields对象代表了在表中的所有列。 Properties Properties集合是Property对象的集合(参看前面“Property对象”部分)。不同的数据提供者比如Microsoft SQL Server和Microsoft Access在Field对象的Properties集合内具有不同的属性。这些属性影响Fields对象的...
数据字典(Data Dictionary)中存储了诸多数据库的元数据信息,包括基本Database, table, index, column, function, trigger, procedure,privilege等;以及与存储引擎相关的元数据,如InnoDB的tablespace, table_id, index_id等。MySQL8.0在数据字典上进行了诸多优化,下面会针对MySQL 8.0的数据字典做相关优化做详细的介绍。
in particular how they are ordered in the LRU list that determines which pages to evict【ɪˈvɪkt 驱逐;逐出;(尤指依法从房屋或土地上)赶出;】 from the buffer pool when it becomes full. The INNODB_BUFFER_PAGE_LRU table has the same columns as the INNODB_BUFFER_PAGE table, except...
(a INT NOT NULL AUTO_INCREMENT PRIMARY KEY, joke TEXT NOT NULL); LOAD DATA INFILE'/tmp/jokes.txt' INTO TABLE jokes FIELDS TERMINATED BY '' LINES TERMINATED BY '\n%%\n' (joke); 八、存储引擎 MySQL属于独有的插件式结构,支持多种存储引擎,每种引擎都有自己的特性。可根据实际需要选用不同的存...
1 row in set (0.00 sec)mysql>我们看到,第一条语句中表名使用了保留字interval,执行失败;第二条语句对interval加了引号,执行成功。在这里需要注意的是,引号必须是反引号,而非单引号。否则会报错,如下所示:1 2 3 4 5 6 7 8 9 mysql>mysql> drop table `interval`;--使用反引号...
事务对文件进行修改时,会获得新的Page,并加入Current的Page Table,所有的修改都只发生在Current Directory;事务Commit时,Current指向的Page刷盘,并通过原子的操作将Current的Page Table合并到Shadow Directory中,之后再返回应用Commit成功;事务Abort时只需要简单的丢弃Current指向的Page;如果过程中发生故障,只需要恢复Shadow ...
5.4.43 mysql_list_fields() MYSQL_RES*mysql_list_fields(MYSQL*mysql,constchar*table,constchar*wild) Description Note As of MySQL 5.7.11,mysql_list_fields()is deprecated and is subject to removal in a future version of MySQL. Instead, usemysql_real_query()ormysql_query()to execute aSHOW ...
INTO TABLE xxxxxx FIELDS TERMINATED BY ',' LINES TERMINATED BY "\r\n" 1. 2. 3. 有时需要导出CSV的表头,此时需要使用union进行处理: select * from ( SELECT '姓名','身份证号码','盟市','旗县' UNION SELECT * from table ) t INTO OUTFILE "/tmp/xxx.csv" FIELDS TERMINATED BY ',' LINES...
setup_wild:Expand all '*' in list of expressions with the matching column references. setup_base_ref_items:Set query_block's base_ref_items. setup_fields:Check that all given fields exists and fill struct with current data. setup_conds:Resolve WHERE condition and join conditions. ...
table, const char *wild) Description Note mysql_list_fields() is deprecated and is subject to removal in a future version of MySQL. Instead, use mysql_real_query() or mysql_query() to execute a SHOW COLUMNS statement. Returns an empty result set for which the metadata provides ...