您好,登錄后才能下訂單哦!
在以數據庫指定表方式導出表序列、結構和數據時,發生表結構和數據被導出,序列沒有被導出,于是整理了一下說明了序列的正確創建方式
一、序列創建方法
1.serial primary key方式建立序列
testdb=#
testdb=# create table t1(id serial primary key, name varchar(10));
CREATE TABLE
testdb=# insert into t1(name) values('David');
INSERT 0 1
testdb=# insert into t1(name) values('Peter');
INSERT 0 1
testdb=#
testdb=#
2.表和序列分別建立,序列附加到表
1).建立表
testdb=# create table t2(id bigint, name varchar(10));
CREATE TABLE
2).建立索引
testdb=# create sequence t2_id_seq increment by 1 minvalue 1 no maxvalue start with 1;
CREATE SEQUENCE
3).設置序列擁有者
testdb=# ALTER SEQUENCE t2_id_seq OWNED BY t2.id;
ALTER SEQUENCE
4).設置序列對應列默認值
testdb=# ALTER TABLE ONLY t2 ALTER COLUMN id SET DEFAULT nextval('t2_id_seq'::regclass);
ALTER TABLE
testdb=#
5).設置ID列主鍵約束
testdb=#
testdb=# ALTER TABLE ONLY t2 ADD CONSTRAINT t2_pkey PRIMARY KEY (id);
ALTER TABLE
testdb=#
6).插入數據
testdb=# insert into t2(name) values('Jean');
INSERT 0 1
testdb=# insert into t2(name) values('jesmean');
INSERT 0 1
testdb=#
testdb=#
testdb=#
testdb=# \d t1_id_seq
Sequence "public.t1_id_seq"
Column | Type | Value
---------------+---------+---------------------
sequence_name | name | t1_id_seq
last_value | bigint | 2
start_value | bigint | 1
increment_by | bigint | 1
max_value | bigint | 9223372036854775807
min_value | bigint | 1
cache_value | bigint | 1
log_cnt | bigint | 31
is_cycled | boolean | f
is_called | boolean | t
Owned by: public.t1.id
testdb=#
testdb=#
testdb=# \d t2_id_seq
Sequence "public.t2_id_seq"
Column | Type | Value
---------------+---------+---------------------
sequence_name | name | t2_id_seq
last_value | bigint | 2
start_value | bigint | 1
increment_by | bigint | 1
max_value | bigint | 9223372036854775807
min_value | bigint | 1
cache_value | bigint | 1
log_cnt | bigint | 31
is_cycled | boolean | f
is_called | boolean | t
Owned by: public.t2.id
testdb=#
testdb=#
testdb=#
testdb=# \q
二、驗證序列是否粘連表
1.表導出時附帶序列
1).導出指定表,看是否包含序列
[postgres@localhost ~]$ pg_dump -Fc -d testdb --table=t1 -f testdb_t1_Fc.dump
[postgres@localhost ~]$ pg_dump -Fc -d testdb --table=t2 -f testdb_t2_Fc.dump
[postgres@localhost ~]$
2).建立新數據庫
[postgres@localhost ~]$
[postgres@localhost ~]$ createdb tdb
[postgres@localhost ~]$
3).導入數據及表結構
[postgres@localhost ~]$
[postgres@localhost ~]$ pg_restore -d tdb testdb_t1_Fc.dump
[postgres@localhost ~]$ pg_restore -d tdb testdb_t2_Fc.dump
[postgres@localhost ~]$
[postgres@localhost ~]$
4).查看表結構
[postgres@localhost ~]$
[postgres@localhost ~]$ psql tdb
psql (9.5.2)
Type "help" for help.
tdb=#
tdb=# \dt
List of relations
Schema | Name | Type | Owner
--------+------+-------+----------
public | t1 | table | postgres
public | t2 | table | postgres
(2 rows)
tdb=# \d t1
Table "public.t1"
Column | Type | Modifiers
--------+-----------------------+-------------------------------------------------
id | integer | not null default nextval('t1_id_seq'::regclass)
name | character varying(10) |
Indexes:
"t1_pkey" PRIMARY KEY, btree (id)
tdb=# \d t2
Table "public.t2"
Column | Type | Modifiers
--------+-----------------------+-------------------------------------------------
id | bigint | not null default nextval('t2_id_seq'::regclass)
name | character varying(10) |
Indexes:
"t2_pkey" PRIMARY KEY, btree (id)
5).查看序列
tdb=# \d t1_id_seq
Sequence "public.t1_id_seq"
Column | Type | Value
---------------+---------+---------------------
sequence_name | name | t1_id_seq
last_value | bigint | 2
start_value | bigint | 1
increment_by | bigint | 1
max_value | bigint | 9223372036854775807
min_value | bigint | 1
cache_value | bigint | 1
log_cnt | bigint | 0
is_cycled | boolean | f
is_called | boolean | t
Owned by: public.t1.id
tdb=# \d t2_id_seq
Sequence "public.t2_id_seq"
Column | Type | Value
---------------+---------+---------------------
sequence_name | name | t2_id_seq
last_value | bigint | 2
start_value | bigint | 1
increment_by | bigint | 1
max_value | bigint | 9223372036854775807
min_value | bigint | 1
cache_value | bigint | 1
log_cnt | bigint | 0
is_cycled | boolean | f
is_called | boolean | t
Owned by: public.t2.id
tdb=#
6).插入數據
tdb=#
tdb=# insert into t1(name) values('chris');
INSERT 0 1
tdb=# insert into t2(name) values('LCH');
INSERT 0 1
tdb=#
tdb=#
tdb=# select * from t1;
id | name
----+-------
1 | David
2 | Peter
3 | chris
(3 rows)
tdb=# select * from t2;
id | name
----+---------
1 | Jean
2 | jesmean
3 | LCH
(3 rows)
tdb=#
tdb=#
tdb=#
tdb=# \d t1_id_seq
Sequence "public.t1_id_seq"
Column | Type | Value
---------------+---------+---------------------
sequence_name | name | t1_id_seq
last_value | bigint | 3
start_value | bigint | 1
increment_by | bigint | 1
max_value | bigint | 9223372036854775807
min_value | bigint | 1
cache_value | bigint | 1
log_cnt | bigint | 32
is_cycled | boolean | f
is_called | boolean | t
Owned by: public.t1.id
tdb=#
tdb=#
tdb=#
tdb=# \d t2_id_seq
Sequence "public.t2_id_seq"
Column | Type | Value
---------------+---------+---------------------
sequence_name | name | t2_id_seq
last_value | bigint | 3
start_value | bigint | 1
increment_by | bigint | 1
max_value | bigint | 9223372036854775807
min_value | bigint | 1
cache_value | bigint | 1
log_cnt | bigint | 32
is_cycled | boolean | f
is_called | boolean | t
Owned by: public.t2.id
tdb=#
tdb=#
2.表刪除時序列是否跟隨刪除
1).原數據庫
testdb=#
testdb=# drop table t1;
DROP TABLE
testdb=#
testdb=#
testdb=# drop table t2;
DROP TABLE
testdb=#
testdb=#
testdb=# \d t1_id_seq
Did not find any relation named "t1_id_seq".
testdb=#
testdb=#
testdb=# \d t2_id_seq
Did not find any relation named "t2_id_seq".
testdb=#
testdb=#
2).導入數據庫
tdb=#
tdb=#
tdb=# drop table t1;
DROP TABLE
tdb=#
tdb=# drop table t2;
DROP TABLE
tdb=#
tdb=#
tdb=#
tdb=# \d t1_id_seq
Did not find any relation named "t1_id_seq".
tdb=#
tdb=#
tdb=# \d t2_id_seq
Did not find any relation named "t2_id_seq".
tdb=#
tdb=#
免責聲明:本站發布的內容(圖片、視頻和文字)以原創、轉載和分享為主,文章觀點不代表本網站立場,如果涉及侵權請聯系站長郵箱:is@yisu.com進行舉報,并提供相關證據,一經查實,將立刻刪除涉嫌侵權內容。