The below given example uses CREATE TABLE statement to create a table with a single column primary key.1 2 3 4 5 6 7 SQL> create table MYTABLE( name VARCHAR2(50), id NUMBER, salary NUMBER(8,2), CONSTRAINT MYTABL
2、命令: create table :创建 alter table 修改 drop table 删除表 truncate table 删除表数据(不可以回滚) 2、创建表: -- 创建表 create table sclass( cid int primary key, cname varchar(10) ) create tableJava( ssid int primary key, -- 主键约束 sname varchar2(20) unique, -- 唯一约束 ssex...
Now let us take an example to understand better. In this example, we will create a Student table with three columns named Student_id, Student_name, and Class. Let us look at the query below: CREATE TABLE Students (Student_id varchar(20) primary key, Student_name varchar(10), Class varc...
CREATE TABLE tablename ( id INT PRIMARY KEY, name VARCHAR(50), age INT ); 新建输出字段:单击+新建输出字段,根据页面提示填写字段并选择类型。当前行完成配置后,单击图标保存。 映射关系 根据上游的输入和目标表的字段,可以手动选择字段映射。快速映射包括同行映射和同名映射。 同名映射:对字段名称相同的字段进...
CREATE USER SCOTT IDENTIFIED BY TIGER; GRANT CONNECT,RESOURCE,UNLIMITED TABLESPACE TO SCOTT ; --GRANT CONNECT,RESOURCE,UNLIMITED TABLESPACE TO SCOTT IDENTIFIED BY TIGER CONTAINER=ALL ; CONNECT SCOTT/tiger CREATE TABLE DEPT (DEPTNO NUMBER(2) CONSTRAINT PK_DEPT PRIMARY KEY, ...
Now the only problem with this Oracle CREATE TABLE statement is that you have not defined a primary key for the table. We could modify this CREATE TABLE statement and define the customer_id as the primary key as follows: CREATE TABLE customers ( customer_id number(10) NOT NULL, customer_...
官方描述:A table is the basic unit of data organization in an Oracle database. A table describes an entity, which is something of significance about which information must be recorded. For example, an employee could be an entity. /*常用语法*/CREATETABLE[schema.]table_name[ORGANIZATION HEAP]...
Cause: The table doesn't have a primary key.Resolution: The Oracle Database connector requires that you use a table with a primary key column.General Limits展開資料表 NameValue Maximum number of requests being processed by the connector concurrently per connection 200 Maximum number of megabytes...
But the biggest advantage (IMO) comes for tables with a multi-column primary key. For example many-to-many join tables. Such as customers to their addresses:Copy code snippet Copied to Clipboard Error: Could not Copy Copied to Clipboard Error: Could not Copy create table customer_address...
SQL> alter table users rename column ID to PID; 修改表的列的字符大小 SQL> alter table student modify class varchar2(10); 创建主键: SQL> alter table users add constraint pk_users primary key(name); 修改表的列数据类型: SQL> select * from users; ...