小编Ric*_*ard的帖子

我想知道这在 Postgres 中是否可行：

最好用一个人为的例子来解释：

create or replace function test_function(filter_param1 varchar default null
                                       , filter_param2 varchar default null)
  returns integer as
$$ 
declare
  stmt text;
  args varchar[];
  wher varchar[];
  retid integer;
begin
  if filter_param1 is not null then 
    array_append(args, filter_param1);
    array_append(wher, 'parameter_name = $1');
  end if;
  if filter_param2 is not null then 
    array_append(args, filter_param2);
    array_append(wher, 'parameter_name = $2');
  end if;

  stmt := 'select id from mytable where ' || array_to_string(wher, ' or ');
  execute stmt into retid using args;

  return retid; …

我继承了这个数据库，它有一个定义如下的表：

CREATE TABLE home_tickets(
    id int IDENTITY(1,1) NOT NULL,
    identifier nvarchar(45) NOT NULL,
    start_date_time datetime NOT NULL,
    revised bit NOT NULL,
    agency_code nvarchar(100) NOT NULL,
    archived tinyint NOT NULL,

    CONSTRAINT PK__home_tic__3213E83F236943A5 PRIMARY KEY CLUSTERED (id ASC) WITH (
        PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON PRIMARY,

    CONSTRAINT UQ__home_tic__969168722645B050 UNIQUE NONCLUSTERED (identifier ASC) WITH (
        PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON PRIMARY …