Question

我正在尝试在触发器函数中执行动态查询，但我不断获得Missing FROM-clause entry for table "new"

为什么会出现错误以及如何解决？

CREATE OR REPLACE FUNCTION "Site"."UpdateAncestorModified"()
  RETURNS trigger AS
$BODY$BEGIN
    EXECUTE
        format
        ('
            UPDATE 
                "' || TG_TABLE_SCHEMA || '"."' || TG_TABLE_NAME || '" 
            SET
                modified = NEW.modified
            WHERE
                id = NEW."ancestorId"
            AND
                modified <> NEW.modified
        ')
    USING
        NEW;
    RETURN NEW;
END$BODY$
  LANGUAGE plpgsql VOLATILE
  COST 100;

Answer 1

我必须将NEW更改为($1)，因为它是对第一个绑定参数的引用。

正确的查询是：

CREATE OR REPLACE FUNCTION "Site"."UpdateAncestorModified"()
  RETURNS trigger AS
$BODY$BEGIN
    EXECUTE
        format
        ('
            UPDATE 
                "' || TG_TABLE_SCHEMA || '"."' || TG_TABLE_NAME || '" 
            SET
                modified = ($1).modified
            WHERE
                id = ($1)."ancestorId"
            AND
                modified <> ($1).modified
        ')
    USING
        NEW;
    RETURN NEW;
END$BODY$
  LANGUAGE plpgsql VOLATILE
  COST 100;

PostgreSQL中触发函数的动态查询

1 个答案: