ORACLE:
1、查主键名称：
select * from user_constraints
where table_name = 'AAA'
and constraint_type ='P';
查主键对应的列：
select * from user_cons_columns
where table_name = 'AAA'
and constraint_name = 'PK_AAA'; (PK_AAA 是主键名)
2、查索引名称：
select * from user_indexes
where table_name = 'AAA';
查索引对应的列：
select * from user_ind_columns
where table_name = 'AAA'
and index_name = 'INDX_BA'; (INDX_BA 是 索引名)
了解几个字典表的用处 如：user_constraints
添加主键：
alter table TableName
add constraint PK NAME
primary key("ACCOUNTINGTASKID"...);
删除主键：
alter table EXTRACTED_POSTING(tablle name)
drop constraint EXTRACTED_POSTING_ACCTID_PK;(PK name)