database - PostgreSQL 在函数中声明变量

Question

我使用 Potgresql 并且编写了函数

CREATE OR REPLACE FUNCTION staging.shape_commit(layer_id integer)
  RETURNS integer AS
$BODY$
declare     
  layer_name text;

begin
layer_name:=(select shape.layer_name from staging.shape where shape.id=layer_id);
delete  from layer_name;
return layer_name;
end;
$BODY$
  LANGUAGE plpgsql VOLATILE
  COST 100;
ALTER FUNCTION staging.shape_commit(integer)
  OWNER TO test;

layer_name 是变量，实际上是表名。但是脚本将其作为变量忽略并用作字符串

卡有人帮我吗？

Answer 1

您的问题不太清楚，但我怀疑您实际上想将文本转换为表名。为此，您需要动态 SQL。代替：

delete  from layer_name;

尝试更多类似的东西：

execute $x$delete from $x$ || layer_name::regclass;

http://www.postgresql.org/docs/current/static/plpgsql-statements.html