我正在创建一个存储过程来复制在mapserver上的mapfile中找到的查询的输出。
查询：
select g.gid, g.geom, g.basin, a.\"DATE\", a.\"VALUE\"
from sarffg_basins_00_regional_3sec as g
join \"%prod_table%\" as a on g.basin = a.\"BASIN\"
where a.\"DATE\" = '%prod_date%'
由于SO帖子长度限制，我无法完整地发布输出，但重要的是这个查询给了我带有列名的输出。调整语法以匹配在sql shell中运行的传统sql：
select g.gid,
g.geom,
g.basin,
a."DATE",
a."VALUE" from sarffg_basins_00_regional_3sec
as g
join "FFGS_PROCESSED_PRODUCT_ASM_SACSMA_UPPER_BASIN_TIMESERIES"
as a on g.basin = a."BASIN" where a."DATE" = '2017-01-12 18:00:00+00';
给出了列
gid | geom | basin | DATE | VALUE
我的存储过程具有以下返回标头：
RETURNS table (
gid integer,
geom geometry(MultiPolygon,4326),
basin double precision,
date timestamptz,
value double precision
)
返回声明：
RETURN QUERY
EXECUTE 'SELECT g.'||quote_ident('gid')||',
g.'||quote_ident('geom')||',
g.'||quote_ident('basin')||',
a.'||quote_ident('DATE')||',
a.'||quote_ident('VALUE')||'
FROM sarffg_basins_00_regional_3sec AS g JOIN '||quote_ident(prod_table)||' AS a
ON g.'||quote_ident('basin')||' = a.'||quote_ident('BASIN')||'
WHERE a.'||quote_ident('DATE')||' = '''||adj_timestamp||'''';
这给了我相同的输出，但没有列名。我认为这是我的mapfile错误日志中出现此错误的原因：
Query error. Error executing query: ERROR: column "VALUE" does not exist LINE 1: select "VALUE",encode(ST_AsBinary(ST_Force2D("geom"),'NDR'),...
我知道prod_table中存在“VALUE”列，特别是考虑到在psql shell中调用此函数时可以正常工作。
如何使输出具有列标题？
编辑：地图文件上的更多上下文。
mapfile中的整个查询如下：
geom from (select g.gid, g.geom, g.basin, a.\"DATE\", a.\"VALUE\" from sarffg_basins_00_regional_3sec as g join \"%prod_table%\" as a on g.basin = a.\"BASIN\" where a.\"DATE\" = '%prod_date%') as subquery using unique gid using srid=4326
我基本上需要使用存储过程复制此功能，无论是完全还是仅仅子查询。我可以在这里找到各种尝试：Syntax error at or near "USING"。似乎我最接近试图只复制子查询 - 即
geom from (select * from ingest_ffgs_prod_composite_csv('%prod_table%', 1484438400)) as subquery using unique gid using srid=4326
编辑3：根据要求，这是整个功能。
CREATE OR REPLACE FUNCTION ingest_ffgs_prod_composite_csv(prod_table text, epoch_seconds bigint, original boolean DEFAULT false, roll_back boolean DEFAULT true)
RETURNS table (
gid integer,
geom geometry(MultiPolygon,4326),
basin double precision,
date timestamptz,
VALUE double precision
)
AS $$
DECLARE
c01n text := 'BASIN'; c01t text := 'double precision';
c02n text := 'MAP01'; c02t text := 'double precision';
c03n text := 'MAP03'; c03t text := 'double precision';
c04n text := 'MAP06'; c04t text := 'double precision';
c05n text := 'MAP24'; c05t text := 'double precision';
c06n text := 'GMAP06'; c06t text := 'double precision';
c07n text := 'GMAP24'; c07t text := 'double precision';
c08n text := 'ASMU06'; c08t text := 'double precision';
c09n text := 'ASML06'; c09t text := 'double precision';
c10n text := 'ASMT06'; c10t text := 'double precision';
c11n text := 'FFG01'; c11t text := 'double precision';
c12n text := 'FFG03'; c12t text := 'double precision';
c13n text := 'FFG06'; c13t text := 'double precision';
c14n text := 'PREVFFG01'; c14t text := 'double precision';
c15n text := 'PREVFFG03'; c15t text := 'double precision';
c16n text := 'PREVFFG06'; c16t text := 'double precision';
c17n text := 'FMAP01'; c17t text := 'double precision';
c18n text := 'FMAP03'; c18t text := 'double precision';
c19n text := 'FMAP06'; c19t text := 'double precision';
c20n text := 'IFFT01'; c20t text := 'double precision';
c21n text := 'IFFT03'; c21t text := 'double precision';
c22n text := 'IFFT06'; c22t text := 'double precision';
c23n text := 'PFFT01'; c23t text := 'double precision';
c24n text := 'PFFT03'; c24t text := 'double precision';
c25n text := 'PFFT06'; c25t text := 'double precision';
c26n text := 'FFFT01'; c26t text := 'double precision';
c27n text := 'FFFT03'; c27t text := 'double precision';
c28n text := 'FFFT06'; c28t text := 'double precision';
c29n text := 'PET06'; c29t text := 'double precision';
tablename_csv text := 'temp_table_csv';
tablename_ts text := 'temp_table_ts';
tablename_ret text := 'temp_table_ret';
full_timestamp timestamptz;
adj_timestamp_text text;
adj_timestamp timestamptz;
year double precision;
month double precision;
day double precision;
hour double precision;
year_text text;
month_text text;
day_text text;
hour_text text;
csv_base_path text;
csv_filename text;
csv_file_full_path text;
ret_rec record;
product text;
interval text;
curr_basin int;
curr_val double precision;
rec record;
existing_table boolean;
existing_data boolean := false;
ret_geom geometry(MultiPolygon,4326);
BEGIN
-- parse prod_table name to determine which product and time interval we need to build a timeseries for
-------------------------------------------------------------------------------------------------------
product := split_part(prod_table, '_', 4);
interval := rtrim(split_part(prod_table, '_', 6), 'HR');
IF interval = 'UPPE' THEN -- asm interval reads as 'UPPE'. Default to 6 hours
interval := '06';
END IF;
raise notice 'product: %', product;
raise notice 'interval: %', interval;
-- convert epoch seconds to timestamp for parsing
-------------------------------------------------
full_timestamp := to_timestamp(epoch_seconds);
year := date_part('year', full_timestamp);
month := date_part('month', full_timestamp);
day := date_part('day', full_timestamp);
IF roll_back THEN
hour := date_part('hour', full_timestamp) - (date_part('hour', full_timestamp)::integer % interval::int);
ELSE
hour := date_part('hour', full_timestamp);
END IF;
year_text := year;
month_text := month;
day_text := day;
hour_text := hour;
IF month < 10 THEN
month_text := '0' || month;
END IF;
IF day < 10 THEN
day_text := '0' || day;
END IF;
IF hour < 10 THEN
hour_text := '0' || hour;
END IF;
adj_timestamp_text := year_text || '-' || month_text || '-' || day_text || ' ' || hour_text || ':00:00+00';
adj_timestamp := adj_timestamp_text::timestamptz;
raise notice 'year: %', year_text;
raise notice 'month: %', month_text;
raise notice 'day: %', day_text;
raise notice 'hour: %', hour_text;
-- check if table with the desired data already exists within the database
--------------------------------------------------------------------------
EXECUTE format('SELECT EXISTS (
SELECT 1
FROM pg_tables
WHERE schemaname = ''public''
AND tablename = '''||prod_table||''')') INTO existing_table;
IF existing_table THEN
EXECUTE format('SELECT EXISTS (
SELECT 1
FROM '||quote_ident(prod_table)||'
WHERE '||quote_ident('DATE')||' = '''||adj_timestamp||''')') INTO existing_data;
END IF;
raise notice 'existing_table: %', existing_table;
raise notice 'existing_data: %', existing_data;
IF NOT existing_data THEN -- need to manually create tables from csv file
-- construct full path to csv file
----------------------------------
csv_base_path := '/SARFFG/EXP/DATA/EXPORTS/REGIONAL/'||year_text||'/'||month_text||'/'||day_text||'/COMPOSITE_CSV';
IF original THEN
csv_filename := year_text||month_text||day_text||'-'||hour_text||'00_ffgs_prod_composite_table_01hr_regional_original.csv';
ELSE
csv_filename := year_text||month_text||day_text||'-'||hour_text||'00_ffgs_prod_composite_table_01hr_regional.csv';
END IF;
csv_file_full_path := csv_base_path||'/'||csv_filename;
-----------------------------------------------
raise notice 'csv file: %', csv_file_full_path;
-- create temporary table to store CSV contents
-----------------------------------------------
EXECUTE format('CREATE TEMP TABLE '||tablename_csv||' ('||c01n||' '||c01t||',
'||c02n||' '||c02t||',
'||c03n||' '||c03t||',
'||c04n||' '||c04t||',
'||c05n||' '||c05t||',
'||c06n||' '||c06t||',
'||c07n||' '||c07t||',
'||c08n||' '||c08t||',
'||c09n||' '||c09t||',
'||c10n||' '||c10t||',
'||c11n||' '||c11t||',
'||c12n||' '||c12t||',
'||c13n||' '||c13t||',
'||c14n||' '||c14t||',
'||c15n||' '||c15t||',
'||c16n||' '||c16t||',
'||c17n||' '||c17t||',
'||c18n||' '||c18t||',
'||c19n||' '||c19t||',
'||c20n||' '||c20t||',
'||c21n||' '||c21t||',
'||c22n||' '||c22t||',
'||c23n||' '||c23t||',
'||c24n||' '||c24t||',
'||c25n||' '||c25t||',
'||c26n||' '||c26t||',
'||c27n||' '||c27t||',
'||c28n||' '||c28t||',
'||c29n||' '||c29t||') ON COMMIT DROP');
EXECUTE format('COPY '||tablename_csv||' FROM '''||csv_file_full_path||''' DELIMITER '','' CSV HEADER');
-- create temp timeseries table
-------------------------------
EXECUTE format('CREATE TEMP TABLE '||tablename_ts||' (date timestamptz, basin int, value double precision) ON COMMIT DROP');
FOR rec in SELECT * FROM temp_table_csv
LOOP
curr_basin := rec.basin;
IF product = 'MAP' THEN
IF interval = '01' THEN
curr_val := rec.map01;
ELSIF interval = '03' THEN
curr_val := rec.map03;
ELSIF interval = '06' THEN
curr_val := rec.map06;
ELSIF interval = '24' THEN
curr_val := rec.map24;
ELSE
raise warning 'interval not found';
EXIT;
END IF;
ELSIF product = 'ASM' THEN
IF interval = '06' THEN
curr_val := rec.asmu06;
ELSE
raise warning 'interval not found';
EXIT;
END IF;
ELSIF product = 'FFG' THEN
IF interval = '01' THEN
curr_val := rec.ffg01;
ELSIF interval = '03' THEN
curr_val := rec.ffg03;
ELSIF interval = '06' THEN
curr_val := rec.ffg06;
ELSE
raise warning 'interval not found';
EXIT;
END IF;
ELSIF product = 'FFT' THEN
IF interval = '01' THEN
curr_val := rec.fft01;
ELSIF interval = '03' THEN
curr_val := rec.fft03;
ELSIF interval = '06' THEN
curr_val := rec.fft06;
ELSE
raise warning 'interval not found';
EXIT;
END IF;
ELSE
raise warning 'product not found';
EXIT;
END IF;
INSERT INTO temp_table_ts (date, basin, value) VALUES (adj_timestamp, curr_basin, curr_val);
END LOOP;
RETURN QUERY
EXECUTE 'SELECT g.gid,
g.geom,
g.basin,
a.date,
a.value
FROM sarffg_basins_00_regional_3sec
AS g
JOIN '||tablename_ts||'
AS a
ON g.'||quote_ident('basin')||' = a.'||quote_ident('basin')||'
WHERE a.'||quote_ident('date')||' = '''||adj_timestamp||'''';
ELSE
RETURN QUERY
EXECUTE format('SELECT g.gid,
g.geom,
g.basin,
a."DATE",
a."VALUE"
FROM sarffg_basins_00_regional_3sec AS g
JOIN %I AS a ON g.basin = a."BASIN"
WHERE a."DATE" = $1', prod_table)
using adj_timestamp;
END IF;
END;
$$ LANGUAGE plpgsql;
编辑4：经过一些更多的尽职调查后，我又回想起问题来自于输出中缺少列名。我的颜色标记明确引用了“VALUE”，但显然没有列名，它不知道哪个是“VALUE”。
将我的查询更改为
select gid, geom, basin, "DATE", "VALUE" from ingest_ffgs_prod_composite_csv('%prod_table%', 1484438400)
给我我的专栏名称，但遗憾的是没有解决我的问题。
答案 0 :(得分：1)
你的问题太混乱了。不过，我确实注意到了引用标识符的问题。该函数在返回类型中声明：
...
RETURNS table (
...
date timestamptz,
VALUE double precision
)
...但是函数调用不匹配：
select gid, geom, basin, "DATE", "VALUE" from ingest_ffgs_prod_composite_csv(...这完全解释了您的错误消息：
ERROR: column "VALUE" does not exist
因为没有列"VALUE"。只有value（双引或不引用）。
所有未加引号的标识符都在Postgres中转换为小写。因此，VALUE和value（但不是 "VALUE"或"Value"）与 相同，作为标识符 。但不是字符串。使用quote_ident()传递给format()或'%I'时，案例很重要，因为它已被转义。所以：
a.'||quote_ident('DATE')||',
a.'||quote_ident('VALUE')||'
生成a."DATE", a."VALUE"，与a.DATE, a.VALUE不同。
此外，PL / pgSQL或SQL函数的 body 中的列名在外部不可见。只有声明的返回类型才对函数调用很重要。
我通常建议不要将date或value作为列名。 Both are allowed in Postgres, but reserved words in standard SQL.
专门使用合法的小写不带引号的标识符来避免这种混淆。