MySQL simple operation (about field additions, modifications, deletions)

--mysql add field and commentSyntax:AlterTabel table NameAdd columnNew field name type (length definition) Comment'comment content to add'Example:Alter  TableTbl_user_report_smsAdd columnRpproveVARCHAR( -) COMMENT'the province in which the informant was attributed'--Delete FieldSyntax:Alter TableTable nameDropExamples of deleted field names:Alter  TableTbl_user_report_smsDROPReprove;--Update FieldSyntax:Alter TableTable name Modifycolumnfield name definition type (length definition) Example:Alter TableTbl_user_report_sms ModifycolumnRpphoneVARCHAR( -);

MySQL simple operation (about field additions, modifications, deletions)