Postgresql 如何在Postgres中实现清除操作系统软删除记录?
在我的Postgres 9.4数据库中,我有以下触发器/函数,它实现了“软删除”功能:Postgresql 如何在Postgres中实现清除操作系统软删除记录?,postgresql,Postgresql,在我的Postgres 9.4数据库中,我有以下触发器/函数,它实现了“软删除”功能: ALTER TABLE my_schema.my_table ADD COLUMN delete_ind integer CREATE OR REPLACE FUNCTION trigger_mytable_soft_delete() RETURNS trigger AS $$ DECLARE command text := ' SET delete_ind = 1 WHERE
ALTER TABLE my_schema.my_table
ADD COLUMN delete_ind integer
CREATE OR REPLACE FUNCTION trigger_mytable_soft_delete()
RETURNS trigger AS $$
DECLARE
command text := ' SET delete_ind = 1 WHERE uuid_col = $1';
BEGIN
EXECUTE 'UPDATE "my_schema"."my_table"' || TG_TABLE_NAME || command USING OLD.uuid_col;
RETURN NULL;
END;
$$ LANGUAGE plpgsql;
CREATE TRIGGER my_table_soft_delete_trigger
BEFORE DELETE ON "my_schema"."my_table"
FOR EACH ROW EXECUTE PROCEDURE trigger_mytable_soft_delete();
上面的代码为我提供了“软删除”功能,但它也阻止我实际删除/清除那些已标记为已删除的行
所需的新行为是使用此delete函数检查delete_ind字段的值,如果该字段已设置为1,则实际永久清除该行
正确的条件语法是什么,它可以设置delete\u ind.的值,或者根据delete\u ind列的当前值实际删除相关行?只需对函数进行相对较小的修改即可:
CREATE OR REPLACE FUNCTION trigger_mytable_soft_delete()
RETURNS trigger AS
$$
BEGIN
if OLD.delete_ind = 1 then
/* Delete proceeds, you just needs to *do nothing*
except for returning the OLD row as it were */
RETURN OLD ;
else
/* instead of deleting, set a flag */
UPDATE my_schema.my_table
SET deleted_ind = 1
WHERE uuid_col = old.uuid_col ;
/* This will skip the process of this row.
It will also avoid subsequent triggers to be fired, and the row will
not be counted on the rows-affected count. If more triggers need
to be processed, make sure this is the last in the chain.
*/
RETURN NULL ;
end if ;
END;
$$
LANGUAGE plpgsql;
(如果您的函数是逐个表使用的,您可以对其进行硬编码,而不需要动态SQL)
旁注:如果列
delete\u ind
仅用作标志,则最好将其声明为布尔非空
,而不是整数
,只需对函数进行相对较小的修改即可:
CREATE OR REPLACE FUNCTION trigger_mytable_soft_delete()
RETURNS trigger AS
$$
BEGIN
if OLD.delete_ind = 1 then
/* Delete proceeds, you just needs to *do nothing*
except for returning the OLD row as it were */
RETURN OLD ;
else
/* instead of deleting, set a flag */
UPDATE my_schema.my_table
SET deleted_ind = 1
WHERE uuid_col = old.uuid_col ;
/* This will skip the process of this row.
It will also avoid subsequent triggers to be fired, and the row will
not be counted on the rows-affected count. If more triggers need
to be processed, make sure this is the last in the chain.
*/
RETURN NULL ;
end if ;
END;
$$
LANGUAGE plpgsql;
(如果您的函数是逐个表使用的,您可以对其进行硬编码,而不需要动态SQL)
旁注:如果列
delete\u ind
仅用作标志,则最好将其声明为布尔非空
,而不是整数