1. table加字段
ALTER TABLE ${database}.${table} ADD COLUMN ${word} ${type} DEFAULT '${default}' COMMENT '${comment}';
如: ALTER TABLE testdatabase.testtable ADD COLUMN testword varchar(255) DEFAULT '' COMMENT '';
ALTER TABLE ${database}.${table} ADD COLUMN ${word} ${type} DEFAULT '${default}' COMMENT '${comment}';
如: ALTER TABLE testdatabase.testtable ADD COLUMN testword varchar(255) DEFAULT '' COMMENT '';