oracle常用語句

--查詢約束

select * from user_cons_columns

--刪除約束

alter table table_test drop constraint sys_c0039695;

--新增主鍵

alter table table_test add primary key (id,fund_code)

--新增唯一約束

alter table table_test

add constraint  uk_table_test_isscode_fundcode

unique (issuer_code,fund_code);

1、只複製表結構的sql

create table b as select * from a where 1<>1

2、即複製表結構又複製表中資料的sql

create table b as select * from a

3、複製表的制定欄位的sql

create table b as select row_id,name,age from a where 1<>1//前提是row_id,name,age都是a表的列

4、複製表的指定欄位及這些指定欄位的資料的sql

create table b as select row_id,name,age from a

以上語句雖然能夠很容易的根據a表結構複製建立b表，但是a表的索引等卻複製不了，需要在b中手動建立。

5、insert into 會將查詢結果儲存到已經存在的表中

insert into t2(column1, column2, ....) select column1, column2, .... from t1

insert into branch select * from branch_bak

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