以下的文章主要讲述的是mysql表修改,即,增加或是删减列与创建或取消索引等相关操作,我们大家都知道mysql在创建一个相关的数据库后,如果接着继续创建一张表而且加如了一些字段,那么我以后还想再增加字段怎么做? 解答:使用alter table(修改表)! alter t
以下的文章主要讲述的是mysql表修改,即,增加或是删减列与创建或取消索引等相关操作,我们大家都知道mysql在创建一个相关的数据库后,如果接着继续创建一张表而且加如了一些字段,那么我以后还想再增加字段怎么做?
解答:使用alter table(修改表)!
alter table语法:
alter [ignore] table tbl_name alter_specification [, alter_specification] ... alter_specification: add [column] column_definition [first | after col_name ] | add [column] (column_definition,...) | add index [index_name] [index_type] (index_col_name,...) | add [constraint [symbol]] primary key [index_type] (index_col_name,...) | add [constraint [symbol]] unique [index_name] [index_type] (index_col_name,...) | add [fulltext|spatial] [index_name] (index_col_name,...) | add [constraint [symbol]] foreign key [index_name] (index_col_name,...) [reference_definition] | alter [column] col_name {set default literal | drop default} | change [column] old_col_name column_definition [first|after col_name] | modify [column] column_definition [first | after col_name] | drop [column] col_name | drop primary key | drop index index_name | drop foreign key fk_symbol | disable keys | enable keys | rename [to] new_tbl_name | order by col_name | convert to character set charset_name [collate collation_name] | [default] character set charset_name [collate collation_name] | discard tablespace | import tablespace | table_options | partition_options | add partition partition_definition | drop partition partition_names | coalesce partition number | reorganize partition partition_names into (partition_definitions) | analyze partition partition_names | check partition partition_names | optimize partition partition_names | rebuild partition partition_names | repair partition pa
以上的相关内容就是对mysql表修改的介绍,望你能有所收获。