sql - UPDATE table_name SET col_name = varchar WHERE col_name 为 NULL；

Question

以下更新失败：-

UPDATE table_name SET col_name = varchar WHERE col_name is NULL;

失败消息是：-

ERROR:  column "varchar" does not exist

而下面提到的成功：-

UPDATE table_name SET col_name = 889977 WHERE col_name is NULL;

我已经检查了pg_typeof列 - col_name 是 character varying. 请帮忙。

Answer 1

我想你错过了字符串的报价

UPDATE table_name SET col_name = 'varchar' WHERE col_name is NULL;