oracle 字段类型修改

ALTER TABLE exb_personnel RENAME COLUMN state TO state1;
ALTER TABLE exb_personnel ADD state  char(1);
UPDATE exb_personnel SET state = CAST(state1 AS char(1));
ALTER TABLE exb_personnel DROP COLUMN state1;

ALTER TABLE exb_personnel RENAME COLUMN state TO state1;
ALTER TABLE exb_personnel ADD state  char(1);
UPDATE exb_personnel SET state = CAST(state1 AS char(1));
ALTER TABLE exb_personnel DROP COLUMN state1;