ALTERTABLE表名ADD[COLUMN]字段名字段类型是否可为空COMMENT'注释'AFTER指定某字段;
--COLUMN关键字可以省略不写
mysql>altertablewhite_user_newaddcolumnerpvarchar(50)notnullcomment'erp账号'aftername;
QueryOK,0rowsaffected(0.03sec)
Records:0Duplicates:0Warnings:0
--在name字段后面添加erp字段
mysql>showcreatetablewhite_user_new;
CREATETABLE`white_user_new`(
`id`bigint(20)NOTNULLAUTO_INCREMENTCOMMENT'ID',
`name`varchar(50)NOTNULLCOMMENT'姓名',
`erp`varchar(50)NOTNULLCOMMENT'erp账号',
`created_time`datetimeDEFAULTNULLCOMMENT'创建时间',
`updated_time`datetimeDEFAULTNULLCOMMENT'更新时间',
PRIMARYKEY(`id`)
)ENGINE=InnoDBAUTO_INCREMENT=6DEFAULTCHARSET=utf8COMMENT='新表-白名单表'
mysql>altertablewhite_user_newaddpositionvarchar(50)notnullcomment'岗位'aftername;
QueryOK,0rowsaffected(0.02sec)
Records:0Duplicates:0Warnings:0
--在name字段后面添加position字段。
mysql>showcreatetablewhite_user_new;
CREATETABLE`white_user_new`(
`id`bigint(20)NOTNULLAUTO_INCREMENTCOMMENT'ID',
`name`varchar(50)NOTNULLCOMMENT'姓名',
`position`varchar(50)NOTNULLCOMMENT'岗位',
`erp`varchar(50)NOTNULLCOMMENT'erp账号',
`created_time`datetimeDEFAULTNULLCOMMENT'创建时间',
`updated_time`datetimeDEFAULTNULLCOMMENT'更新时间',
PRIMARYKEY(`id`)
)ENGINE=InnoDBAUTO_INCREMENT=6DEFAULTCHARSET=utf8COMMENT='新表-白名单表'
mysql>altertablewhite_user_newaddmobilevarchar(50)notnullcomment'手机号码'beforeposition;
--报错,在position字段前添加mobile字段,不能使用before关键字
|