相关疑难解决方法(0)

我写了一个函数,输出一个SELECT以文本形式组成的PostgreSQL 查询.现在我不想再输出文本,但实际上SELECT对数据库运行生成的语句并返回结果 - 就像查询本身一样.

到目前为止我所拥有的:

CREATE OR REPLACE FUNCTION data_of(integer)
  RETURNS text AS
$BODY$
DECLARE
   sensors varchar(100);   -- holds list of column names
   type    varchar(100);   -- holds name of table
   result  text;           -- holds SQL query
       -- declare more variables

BEGIN
      -- do some crazy stuff

      result := 'SELECT\r\nDatahora,' || sensors ||
      '\r\n\r\nFROM\r\n' || type ||
      '\r\n\r\nWHERE\r\id=' || $1 ||'\r\n\r\nORDER BY Datahora;';

      RETURN result;
END;
$BODY$
LANGUAGE 'plpgsql' VOLATILE;
ALTER FUNCTION data_of(integer) OWNER TO postgres;

sensors …

在pgadmin3中,我想使用参数化查询(为了更快的调试,只需从我的php文件中复制并粘贴查询).但是我还没有找到一个选项添加值$1,$2...参数.可能吗？

这是我在循环中构建的查询,遵循此处的 NULL测试建议:

SELECT EXISTS(SELECT 1
              FROM tax
              WHERE (addby=$1 or addby<>$1)
                    AND (adddate=$2 or adddate<>$2)
                    AND ($3 IS NULL AND nome IS NULL OR nome=$3)
                    AND ($4 IS NULL AND rank IS NULL OR rank=$4)
                    AND ($5 IS NULL AND pai IS NULL OR pai=$5)
                    AND ($6 IS NULL AND valido IS NULL OR valido=$6)
                    AND ($7 IS NULL AND sinonvalid IS NULL OR sinonvalid=$7)
                    AND ($8 IS NULL AND espec IS NULL OR …

如何编写包含动态生成的SQL语句的存储过程,该语句返回结果集？这是我的示例代码:

CREATE OR REPLACE FUNCTION reporting.report_get_countries_new (
  starts_with varchar,
  ends_with varchar
)
RETURNS TABLE (
  country_id integer,
  country_name varchar
) AS
$body$
DECLARE
  starts_with ALIAS FOR $1;
  ends_with ALIAS FOR $2;
  sql VARCHAR;
BEGIN

    sql = 'SELECT * FROM lookups.countries WHERE lookups.countries.country_name >= ' || starts_with ;

    IF ends_with IS NOT NULL THEN
        sql = sql || ' AND lookups.countries.country_name <= ' || ends_with ;
    END IF;

    RETURN QUERY EXECUTE sql;

END;
$body$
LANGUAGE 'plpgsql'
VOLATILE
CALLED ON NULL INPUT …

我正在PostgreSQL DB中创建一个存储过程(函数),它根据输入更新表.为了创建一个可变数量的参数函数,我正在创建一个名为mode的额外输入参数,我用它来控制我在更新查询中使用的参数.

CREATE OR REPLACE FUNCTION update_site(
    mode integer,
    name character varying,
    city character varying,
    telephone integer,
)
RETURNS integer AS
$$
BEGIN
IF mode = 0 THEN
BEGIN
    UPDATE "Sites" SET 
    ("City","Telephone") = (city,telephone)
    WHERE "SiteName" = name;
    RETURN 1;
    EXCEPTION WHEN others THEN
    RAISE NOTICE 'Error on site update: %, %',SQLERRM,SQLSTATE;
    RETURN 0;
END;
ELSIF mode = 1 THEN
BEGIN
    UPDATE "Sites" SET "City" = city
    WHERE "SiteName" = name;
    RETURN 1;
    EXCEPTION WHEN others THEN
    RAISE NOTICE …