参数数据类型
更新时间 2025-02-14 10:22:23
最近更新时间: 2025-02-14 10:22:23
本页介绍天翼云TeleDB数据库存储过程开发的参数数据类型。
基本类型
teledb=# CREATE OR REPLACE PROCEDURE p_base_para (a_int integer,a_str text) AS
$$
BEGIN
RAISE NOTICE 'a_int = % ; a_str = %',a_int,a_str;
END;
$$
LANGUAGE PLPGSQL;
CREATE PROCEDURE
teledb=#
CALL p_base_para(1,'teledb_pg');
NOTICE: a_int = 1 ; a_str = teledb_pg
CALL
teledb=#
teledb=# CREATE OR REPLACE PROCEDURE p_base_array (a_int integer[],a_str text[]) AS
$$
BEGIN
RAISE NOTICE 'a_int = % ; a_str = %',a_int,a_str;
END;
$$
LANGUAGE PLPGSQL;
CREATE PROCEDURE
teledb=# CALL p_base_array(ARRAY[1,2,3],ARRAY['teledb_pg','pgxz']);
NOTICE: a_int = {1,2,3} ; a_str = {teledb_pg,pgxz}
CALL
teledb=#复合类型
teledb=# CREATE TYPE public.t_per AS
(
id integer,
mc text
);
CREATE TYPE
teledb=# CREATE OR REPLACE PROCEDURE p_type (a_row public.t_per) AS $$
BEGIN
RAISE NOTICE 'id = % ; mc = %',a_row.id,a_row.mc;
END;
$$
LANGUAGE PLPGSQL;
CREATE PROCEDURE
teledb=# CALL p_type(ROW(1,'teledb_pg')::public.t_per);
NOTICE: id = 1 ; mc = teledb_pg
CALL
teledb=#复合数组
teledb=# CREATE OR REPLACE PROCEDURE p_type_array (a_rec public.t_per[]) AS
$$
BEGIN
RAISE NOTICE 'a_rec = %',a_rec;
RAISE NOTICE 'a_rec[1].id = %',a_rec[1].id;
END;
$$
LANGUAGE PLPGSQL;
CREATE PROCEDURE
teledb=# CALL p_type_array (ARRAY[ROW(1,'teledb_pg'),ROW(1,'pgxz')]::public.t_per[]);
NOTICE: a_rec = {"(1,teledb_pg)","(1,pgxz)"}
NOTICE: a_rec[1].id = 1
CALL
teledb=#行类型
teledb=# create table public.t(id int,mc text);
CREATE TABLE
teledb=#
teledb=# CREATE OR REPLACE PROCEDURE p_row (a_row public.t) AS
$$
BEGIN
RAISE NOTICE 'id = % ; mc = %',a_row.id,a_row.mc;
END;
$$
LANGUAGE PLPGSQL;
CREATE PROCEDURE
teledb=#CALL p_row(ROW(1,'teledb_pg'));
NOTICE: id = 1 ; mc = teledb_pg
CALL
teledb=#行数组
teledb=# CREATE OR REPLACE PROCEDURE p_row_array (a_rec public.t[]) AS
$$
BEGIN
RAISE NOTICE 'a_rec = %',a_rec;
RAISE NOTICE 'a_rec[1].id = %',a_rec[1].id;
END;
$$
LANGUAGE PLPGSQL;
CREATE PROCEDURE
teledb=# CALL p_row_array(array[row(1,'teledb_pg'),row(1,'pgxz')]::public.t[]);
NOTICE: a_rec = {"(1,teledb_pg)","(1,pgxz)"}
NOTICE: a_rec[1].id = 1
CALL
teledb=#游标类型
teledb=# CREATE OR REPLACE PROCEDURE p_refcursor (a_ref refcursor) AS
$$
DECLARE v_rec record;
BEGIN
OPEN a_ref FOR SELECT * FROM t LIMIT 1;
FETCH a_ref INTO v_rec;
RAISE NOTICE 'v_rec = % ',v_rec;
END;
$$
LANGUAGE PLPGSQL;
CREATE PROCEDURE
teledb=# CALL p_refcursor('a');
NOTICE: v_rec = (1,teledb_pg)
CALL
teledb=#
teledb=# CREATE OR REPLACE PROCEDURE f_any(a_arg anyelement) AS
$$
BEGIN
RAISE NOTICE '%',a_arg;
END;
$$
LANGUAGE PLPGSQL;
CREATE PROCEDURE
teledb=# CALL f_any(1);
NOTICE: 1
CALL
teledb=# CALL f_any('teledb_pg'::varchar);
NOTICE: teledb_pg
CALL
teledb=#
teledb=# CALL f_any('teledb_pg'::TEXT);
NOTICE: teledb_pg
f_any
-------
(1 行记录)
teledb=# CALL f_any(ROW(1,'teledb_pg')::public.t);
NOTICE: (1,teledb_pg)
CALL
teledb=#
teledb=# CALL f_any(ARRAY[1,2]::INTEGER[]);
NOTICE: {1,2}
CALL
teledb=#
teledb=# CALL f_any(ARRAY[[1,2],[3,4],[5,6]]::INTEGER[][][]);
NOTICE: {{1,2},{3,4},{5,6}}
CALL
teledb=#
注意多态类型参数调用时最好直接声明参数类型，否则有可能出错。
teledb=# CREATE OR REPLACE PROCEDURE f_any(a_arg anyarray) AS
$$
BEGIN
RAISE NOTICE '%',a_arg;
END;
$$
LANGUAGE PLPGSQL;
CREATE PROCEDURE
teledb=# call f_any(ARRAY['teledb_pg','pgxz']::TEXT[]);
ERROR: procedure f_any(text[]) is not unique
LINE 1: call f_any(ARRAY['teledb_pg','pgxz']::TEXT[]);
^
HINT: Could not choose a best candidate procedure. You might need to add explicit type casts.
teledb=#teledb=# CREATE OR REPLACE PROCEDURE f_any(a_arg anyarray) AS
$$
BEGIN
RAISE NOTICE '%',a_arg;
END;
$$
LANGUAGE PLPGSQL;
CREATE PROCEDURE
teledb=# call f_any(ARRAY['teledb_pg','pgxz']::TEXT[]);
ERROR: procedure f_any(text[]) is not unique
LINE 1: call f_any(ARRAY['teledb_pg','pgxz']::TEXT[]);
^
HINT: Could not choose a best candidate procedure. You might need to add explicit type casts.
teledb=#注意
Anyelement 参数如果写成数组，其意义就跟 anyarray 参数一致，所以 f_any(a_arg anyelement) 与 f_any(a_arg anyarray) 在调用 f_any(ARRAY[1,2]) 时就会出现函数不是唯一化的错误 (ERROR: function f_any(…) is not unique) 提示。
参数默认值
teledb=# CREATE OR REPLACE PROCEDURE p_default_value (a_int INTEGER DEFAULT 1) AS
$$
BEGIN
RAISE NOTICE 'a_int = %',a_int;
END;
$$
LANGUAGE PLPGSQL;
CREATE PROCEDURE
teledb=# CALL p_default_value(2);
NOTICE: a_int = 2
CALL
teledb=# CALL p_default_value();
NOTICE: a_int = 1
CALL
teledb=#如果原来存在一个p_default_value () 这样的存储过程，则上面的执行就会出错，因为系统无法清楚到底要执行哪个函数，如下所示。
teledb=# CREATE OR REPLACE PROCEDURE p_default_value() AS
$$
BEGIN
RAISE NOTICE '无参数';
END;
$$
LANGUAGE plpgsql ;
CREATE PROCEDURE
teledb=# CALL p_default_value();
ERROR: procedure p_default_value() is not unique
LINE 1: CALL p_default_value();
^
HINT: Could not choose a best candidate procedure. You might need to add explicit type casts.
teledb=#出错提示，p_default_value () 存储过程不是唯一的，这是使用上一个需要特别注意的地方。
