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更新时间：2024-06-29 GMT+08:00
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NAMED

Teradata中的NAMED用于为表达式或列分配临时名称。用于表达式的NAMED语句在DWS中被迁移为AS。用于列名的NAMED语句保留在相同的语法中。

输入：NAMED表达式，迁移为AS

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SELECT Name, ((Salary + (YrsExp * 200))/12) (NAMED Projection)
  FROM Employee
 WHERE DeptNo = 600 AND Projection < 2500;

输出

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SELECT Name, ((Salary + (YrsExp * 200))/12) AS  Projection
  FROM Employee
 WHERE DeptNo = 600 AND ((Salary + (YrsExp * 200))/12)  < 2500;

输入：NAMED AS，定义列名

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SELECT product_id AS id
  FROM emp where pid=2 or id=2;

输出

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SELECT product_id (NAMED "pid") AS id
  FROM emp where product_id=2 or product_id=2;

输入：NAMED( )，定义列名

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INSERT INTO Neg100 (NAMED,ID,Dept) VALUES ('TEST',1,'IT');

输出

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INSERT INTO Neg100 (NAMED,ID,Dept) SELECT 'TEST',1, 'IT';

输入：NAMED别名，使用TITLE别名，不使用AS

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SELECT dept_name (NAMED alias1) (TITLE alias2 ) 
  FROM employee 
 WHERE dept_name like 'Quality';

输出

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SELECT dept_name 
    AS alias1 
  FROM employee
 WHERE dept_name like 'Quality';

输入：NAMED别名，使用TITLE别名和AS

DSC将跳过NAMED别名和TITLE别名，仅使用AS别名。

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SELECT sale_name (Named alias1 ) (Title alias2) 
    AS alias3 
  FROM employee 
 WHERE sname = 'Stock' OR sname ='Sales';

输出

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SELECT sale_name 
    AS alias3 
  FROM employee 
 WHERE sname = 'Stock' OR sname ='Sales';

输入：NAMED，使用TITLE

NAMED和TITLE一起使用，通过逗号隔开。

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SELECT customer_id (NAMED cust_id, TITLE 'Customer Id')
FROM Customer_T 
WHERE cust_id > 10;

输出

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SELECT cust_id AS "Customer Id" 
FROM   (SELECT customer_id AS cust_id 
                FROM   customer_t 
                WHERE  cust_id > 10);

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