一
- 给表增加一个字段
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1 alter table t_other_data add data_item2 varchar(200) DEFAULT NULL COMMENT '数据项2'; 2 alter table t_other_data add data_item3 varchar(200) DEFAULT NULL COMMENT '数据项3'; 3 alter table t_other_data add reserve1 varchar(200) DEFAULT NULL COMMENT '预留字段1'; 4 alter table t_other_data add reserve2 varchar(200) DEFAULT NULL COMMENT '预留字段2'; 5 alter table t_other_data add reserve3 varchar(200) DEFAULT NULL COMMENT '预留字段3'; 6 alter table t_other_data add reserve4 varchar(200) DEFAULT NULL COMMENT '预留字段4'; 7 alter table t_other_data add reserve5 varchar(200) DEFAULT NULL COMMENT '预留字段5';
2.给表增加多个字段
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alter table t_meter_data_back add (data1 varchar(200),data2 varchar(200),data3 varchar(200));
3.给表删除一个字段
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alter table t_meter_data_back drop column data1;
4.给表删除多个字段
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
alter table t_meter_data_back drop column data2,drop column data3;