ERROR: syntax error at or near "modify" - in postgres

Question

我在 Postgres 中执行了这条 SQL 语句

alter table user modify column 'distinguishedName1' text;

和

alter table user modify column distinguishedName1 text;

user 是 table 名字
distinguishedName1是整数数据类型的列名。

我想根据用户的输入将数据类型修改为 boolean 或 text 或 varchar(256) 等。但是当我运行查询时，我得到了错误

ERROR: syntax error at or near "modify"

不确定是什么问题。正确查询需要帮助。

Answer 1

试试这个：

ALTER TABLE "user" ALTER COLUMN distinguishedName1 TYPE text USING code::text;

或

ALTER TABLE "user" ALTER COLUMN distinguishedName1 TYPE text

另请注意，USING 是可选的。请在此处查看 manual：

The optional USING clause specifies how to compute the new column value from the old; if omitted, the default conversion is the same as an assignment cast from old data type to new. A USING clause must be provided if there is no implicit or assignment cast from old to new type.

附带说明尽量避免将表命名为 reserved keywords.

Answer 2

POSTGRES 改变列类型的语法：

ALTER TABLE user ALTER COLUMN distinguishedName1 TYPE text;

Answer 3

alter table user Alter column distinguishedName1 text;

语法错误，对于sql服务器你必须使用alter来修改table

的列

ERROR: syntax error at or near "modify" - in postgres

ERROR: syntax error at or near "modify" - in postgres

sql

postgresql

ddl

alter-table