NAME

DROP TYPE - 刪除一個(gè)用戶定義數(shù)據(jù)類型

SYNOPSIS

DROP TYPE name [, ...] [ CASCADE | RESTRICT ]

DESCRIPTION 描述

DROP TYPE 將從系統(tǒng)表里刪除用戶定義的類型。 只有類型所有者可以刪除類型。  

PARAMETERS 參數(shù)

name

 要?jiǎng)h除的類型名（可以有模式修飾）。

CASCADE

 自動(dòng)刪除依賴該類型的對(duì)象（比如表字段，函數(shù)，操作符等等）。

RESTRICT

 如果有依賴對(duì)象，則拒絕刪除該類型。這個(gè)是缺省。

EXAMPLES 例子

 刪除 box 類型：

DROP TYPE box;

COMPATIBILITY 兼容性

 這條命令類似于 SQL 標(biāo)準(zhǔn)里對(duì)應(yīng)的命令，但是要注意，PostgreSQL  里的 CREATE TYPE 命令和數(shù)據(jù)類型擴(kuò)展機(jī)制是和 SQL 標(biāo)準(zhǔn)里不同的。  

SEE ALSO 參見

CREATE TYPE [create_type(7)]

#p#

NAME

DROP TYPE - remove a data type

SYNOPSIS

DROP TYPE name [, ...] [ CASCADE | RESTRICT ]

DESCRIPTION

DROP TYPE will remove a user-defined data type. Only the owner of a type can remove it.  

PARAMETERS

name

The name (optionally schema-qualified) of the data type to remove.

CASCADE

Automatically drop objects that depend on the type (such as table columns, functions, operators).

RESTRICT

Refuse to drop the type if any objects depend on it. This is the default.

EXAMPLES

To remove the data type box:

DROP TYPE box;

COMPATIBILITY

This command is similar to the corresponding command in the SQL standard, but note that the CREATE TYPE command and the data type extension mechanisms in PostgreSQL differ from the SQL standard.  

SEE ALSO

CREATE TYPE [create_type(7)]