我正在尝试编写一个函数,该函数以table名称作为变量运行插入语句,并且Where子句接受数组作为另一个变量。
CREATE OR REPLACE FUNCTION f_dynamic_sql()
RETURNS void
LANGUAGE plpgsql
AS
$body$
DECLARE
rec record;
iterator float4 := 1;
tbl_name text;
BEGIN
DROP TABLE IF EXISTS t_ar; CREATE TEMP TABLE t_ar (reg text, zones text[]);
INSERT INTO t_ar VALUES
('NA', '{"US","UG","UC","UR"}'),
('NE', '{"UK", "SP"}'),
('LA', '{"CA","EC","WC","EC","WC"}');
FOR rec IN SELECT zones from t_ar
LOOP
tbl_name := 'schema.table_' || iterator;
EXECUTE format('INSERT INTO %s
SELECT
DATE_PART(''MONTH'', month)::INT AS month,
SUM(COALESCE(prev_year,0))::INT AS py,
SUM(COALESCE(last_year,0))::INT AS ly
FROM org_table
WHERE load_area IN (SELECT UNNEST(rec.zones))
GROUP BY 1
ORDER BY 1', tbl_name);
iterator := iterator + 1;
END LOOP;
END;
$body$
VOLATILE
COST 100;
这可以通过执行格式运行良好,但是我不能将表名称称为变量,但是在执行格式中,它显示了SQL查询中的语法错误。SQL查询在外面运行。
您需要在format()
函数中使用占位符和参数。
使用EXECUTE format()
时的实用提示 - 使用RAISE NOTICE '%',
代替EXECUTE
,并在PSQL中运行该功能以查看其实际生成的查询。当您确定生成的查询正确时,请用EXECUTE
替换RAISE NOTICE '%',
。示例:
...
FOR rec IN SELECT reg, zones FROM t_ar
LOOP
RAISE NOTICE '%', format('
INSERT INTO my_schema.table_%s
SELECT
DATE_PART(''MONTH'', month)::INT AS month,
SUM(COALESCE(prev_year,0))::INT AS py,
SUM(COALESCE(last_year,0))::INT AS ly
FROM org_table
WHERE load_area = ANY (%L)
GROUP BY 1
ORDER BY 1', rec.reg, rec.zones);
END LOOP;
...