DB2表管理的相關語句是學習DB2數據庫系統的基礎知識，下面就為您詳細介紹一些DB2表管理語句，希望對您學習DB2表管理方面能有所幫助。
創建表
CREATE TABLE BOOKS
( BOOKID INTEGER,
BOOKNAME VARCHAR(100),
ISBN CHAR(10) )
使用like創建表
CREATE TABLE MYBOOKS LIKE BOOKS
制定表空間
db2 create table T1 (c1 int ...) in TS1
db2 create table T2 (c1 float ...) in TS1
刪除表
drop table tab_name
添加刪除列
db2 => create table test (c1 int)
DB20000I The SQL command completed successfully.
db2 => alter table test add c2 char(8)
DB20000I The SQL command completed successfully.
db2 => alter table test drop c2
DB20000I The SQL command completed successfully.
列的修改及限制
1.修改長度
alter table tab_name alter c1 set data type varchar(20)
2.設置為非空
alter table tab_name alter c1 set not null
create table tab_name (id interger not null)
3.設置默認值
create table tab_name (id integer,name varchar(10) with default 'none')
4.為列創建序列
使用關鍵字 generated always as identity
create table tab_name (id integer generated always as identity (start with 1,increment by 1))
5.唯一性約束
使用關鍵字primary key
create table tab_name (id int not null primary key)
使用關鍵字unique
alter table tab_name add constraint unique (id)
create unique index idx_name on tab_name (id)
6.檢查性約束
使用關鍵字check
ALTER TABLE BOOKS ADD BOOKTYPE CHAR(1) CHECK (BOOKTYPE IN ('F','N') )
7.參照約束
使用關鍵字references
CREATE TABLE AUTHORS (AUTHORID INTEGER NOT NULL PRIMARY KEY,
LNAME VARCHAR(100),
FNAME VARCHAR(100))
CREATE TABLE BOOKS (BOOKID INTEGER NOT NULL PRIMARY KEY,
BOOKNAME VARCHAR(100),
ISBN CHAR(10),
AUTHORID INTEGER REFERENCES AUTHORS)
