NAME

DROP CAST - 刪除一個用戶定義的類型轉換

SYNOPSIS

DROP CAST (sourcetype AS targettype) [ CASCADE | RESTRICT ]

DESCRIPTION 描述

DROP CAST 刪除一個前面定義的類型轉換。

 要能刪除一個類型轉換，你必須擁有源或者目的數據類型。 這是和創建一個類型轉換相同的權限。  

PARAMETERS 參數

sourcetype

 類型轉換里的源數據類型。

targettype

 類型轉換里的目的數據類型。

CASCADE

RESTRICT

 這些鍵字沒有任何效果，因為在類型轉換上沒有依賴關系。

EXAMPLES 例子

 刪除從 text 到 int 的轉換：

DROP CAST (text AS int);

COMPATIBILITY 兼容性

DROP CAST 遵循 SQL 標準。  

SEE ALSO 參見

CREATE CAST [create_cast(7)]

#p#

NAME

DROP CAST - remove a cast

SYNOPSIS

DROP CAST (sourcetype AS targettype) [ CASCADE | RESTRICT ]

DESCRIPTION

DROP CAST removes a previously defined cast.

To be able to drop a cast, you must own the source or the target data type. These are the same privileges that are required to create a cast.  

PARAMETERS

sourcetype

The name of the source data type of the cast.

targettype

The name of the target data type of the cast.

CASCADE

RESTRICT

These key words do not have any effect, since there are no dependencies on casts.

EXAMPLES

To drop the cast from type text to type int:

DROP CAST (text AS int);

COMPATIBILITY

The DROP CAST command conforms to the SQL standard.  

SEE ALSO

CREATE CAST [create_cast(7)]