text: ---- ALTER TABLE ...  CHANGE COLUMN  
  -- constraints : no
  -- ordering : change ordering
  -- name : change or not
  -- type : int , not type change 
  -- other :
  
  -- change name + first
  create table t1 ( i1 integer, i2 integer );
  insert into t1 values (1,11),(2,22),(3,33);
  select * from t1 order by 1,2;
  show columns in t1;
  
  alter table t1 change i2 i0 integer first;
  
  select * from t1 order by 1,2;
  show columns in t1;
  
  drop table t1;
  
  
  -- change name + after
  create table t1 ( i1 integer, i2 integer , i3 integer);
  insert into t1 values (1,11,111),(2,22,222),(3,33,333);
  select * from t1 order by 1,2,3;
  show columns in t1;
  
  alter table t1 change i1 i2_b integer after i2;
  
  select * from t1 order by 1,2,3;
  show columns in t1;
  
  drop table t1;
  
  
  
  -- same  name + first
  create table t1 ( i1 integer, i2 integer );
  insert into t1 values (1,11),(2,22),(3,33);
  select * from t1 order by 1,2;
  show columns in t1;
  
  alter table t1 change i2 i2 integer first;
  
  select * from t1 order by 1,2;
  show columns in t1;
  
  drop table t1;
  
  
  -- same name + after
  create table t1 ( i1 integer, i2 integer , i3 integer);
  insert into t1 values (1,11,111),(2,22,222),(3,33,333);
  select * from t1 order by 1,2,3;
  show columns in t1;
  
  alter table t1 change i1 i1 integer after i2;
  
  select * from t1 order by 1,2,3;
  show columns in t1;
  
  drop table t1;
  
  
  
  
  
  
  