模式（schema）实际上一个命名表的集合。也可以包含一个schema视图，索引，序列，数据类型，运算符和函数。Schema是满足类似于在操作系统级别的目录，但该模式不能嵌套。 CREATE SCHEMA PostgreSQL语句创建一个模式（schema）。 www.gitbook.net

语法

创建型模式的基本语法如下： gitbook.net

CREATE SCHEMA name;
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其中，name是模式的名称。 www.gitbook.net

在Schema中创建表的语法

The basic syntax to create table in schema is as follows:

CREATE TABLE myschema.mytable (
...
);
 
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Example

Let us see an example for creating a schema. Connect to the database testdb and create a schemamyschema as follows: www.gitbook.net

testdb=# create schema myschema;
CREATE SCHEMA
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The message "CREATE SCHEMA" signifies that the schema is created successfully. gitbook.net

Now, let us create a table in the above schema as follows: gitbook.net

testdb=# create table myschema.company(
   ID   INT              NOT NULL,
   NAME VARCHAR (20)     NOT NULL,
   AGE  INT              NOT NULL,
   ADDRESS  CHAR (25) ,
   SALARY   DECIMAL (18, 2),
   PRIMARY KEY (ID)
   );
 
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This will create an empty table. You can verify the table created with the command below:

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testdb=# select * from myschema.company;
 
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This would produce following result:

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 id | name | age | address | salary
----+------+-----+---------+--------
(0 rows)
 
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删除模式语法

To drop a schema if it's empty (all objects in it have been dropped), then use:

DROP SCHEMA myschema;
 
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To drop a schema including all contained objects, use:

DROP SCHEMA myschema CASCADE;
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使用模式的优势

• It allows many users to use one database without interfering with each other.

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• It organizes database objects into logical groups to make them more manageable.

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• Third-party applications can be put into separate schemas so they do not collide with the names of other objects.

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