创建表后，在表中添加一列

Question

我已经创建了一个名为starsin的表。现在，我想使用查询在表address中添加列starsin。我怎么能这样做？

Answer 1

在标准SQL中，您需要alter table X add column Y ...命令。

如果您想填充所有现有行的列，则只需编制查询即可：update X set Y = ...。

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这是一个示例会话，向您展示运行中的alter table add column（对于DB2）：

> CREATE TABLE XYZ (F1 INTEGER);                       
DSNE616I STATEMENT EXECUTION WAS SUCCESSFUL, SQLCODE IS 0  

> INSERT INTO XYZ VALUES (1);                          
DSNE615I NUMBER OF ROWS AFFECTED IS 1                      
DSNE616I STATEMENT EXECUTION WAS SUCCESSFUL, SQLCODE IS 0  

> INSERT INTO XYZ VALUES (2);                          
DSNE615I NUMBER OF ROWS AFFECTED IS 1                      
DSNE616I STATEMENT EXECUTION WAS SUCCESSFUL, SQLCODE IS 0  

> SELECT * FROM XYZ;                                   
F1                                                
--
 1                                                
 2                                                
DSNE610I NUMBER OF ROWS DISPLAYED IS 2                     
DSNE616I STATEMENT EXECUTION WAS SUCCESSFUL, SQLCODE IS 100

> ALTER TABLE XYZ ADD COLUMN F2 INTEGER;               
DSNE616I STATEMENT EXECUTION WAS SUCCESSFUL, SQLCODE IS 0  

> UPDATE XYZ SET F2 = F1 + 7;                          
DSNE615I NUMBER OF ROWS AFFECTED IS 2                      
DSNE616I STATEMENT EXECUTION WAS SUCCESSFUL, SQLCODE IS 0  

> SELECT * FROM XYZ;                                   
F1   F2                                   
--   --
 1    8                                   
 2    9                                   
DSNE610I NUMBER OF ROWS DISPLAYED IS 2                     
DSNE616I STATEMENT EXECUTION WAS SUCCESSFUL, SQLCODE IS 100

Answer 2

如果这是mysql，您可以ALTER TABLE stasin ADD COLUMN <columnname> <type> <options>

Answer 3

请参阅here

代码：

ALTER TABLE Sales 
ADD UnitPrice MONEY;

输出： 命令已成功完成。 说明： 此示例通过指定新字段名称和数据类型将单个字段添加到“Sales”表。 语言：MS SQL Server

Answer 4

ALTER TABLE <table name> ADD(<coloumn name> <datatype>);

正常SQL查询以添加列。在oracle中，它会起作用。