我有一个函数（audit.create_audit_table()）接受一个表名数组。它创建一个函数audit.if_modified_func()，然后遍历每个表名并创建一个审计表并将触发器应用于主表。该函数编译并创建没有错误。当我运行该功能
select audit.create_audit_table(ARRAY['organization'])
我一直得到以下错误，我不知道为什么因为我认为TG_TABLE_NAME是一个自动变量，它将让我访问正在执行audit.if_modified_func()的当前表
错误：
ERROR: column "tg_table_name" does not exist
LINE 3: audit_row audit.' || quote_ident(TG_TABLE_NAME::TEXT)||';
^
这是功能：
CREATE OR REPLACE FUNCTION audit.create_audit_table(table_names character varying[])
RETURNS character varying AS
$BODY$
DECLARE
table_name varchar;
i int;
BEGIN
EXECUTE 'CREATE OR REPLACE FUNCTION audit.if_modified_func() RETURNS TRIGGER AS $$
DECLARE
audit_row audit.' || quote_ident(TG_TABLE_NAME::TEXT)||';
include_values boolean;
log_diffs boolean;
h_old hstore;
h_new hstore;
excluded_cols text[] = ARRAY[]::text[];
BEGIN
IF TG_WHEN <> ''AFTER'' THEN
RAISE EXCEPTION ''audit.if_modified_func() may only run as an AFTER trigger'';
END IF;
audit_row = ROW(
nextval(''audit.'|| quote_ident(TG_TABLE_NAME::text) ||'_event_id_seq''), -- event_id
TG_TABLE_SCHEMA::text, -- schema_name
TG_TABLE_NAME::text, -- table_name
TG_RELID, -- relation OID for much quicker searches
session_user::text, -- session_user_name
current_timestamp, -- action_tstamp_tx
statement_timestamp(), -- action_tstamp_stm
clock_timestamp(), -- action_tstamp_clk
txid_current(), -- transaction ID
current_setting(''application_name''), -- client application
inet_client_addr(), -- client_addr
inet_client_port(), -- client_port
current_query(), -- top-level query or queries (if multistatement) from client
substring(TG_OP,1,1), -- action
NULL, NULL, -- row_data, changed_fields
''f'' -- statement_only
);
IF NOT TG_ARGV[0]::boolean IS DISTINCT FROM ''f''::boolean THEN
audit_row.client_query = NULL;
END IF;
IF TG_ARGV[1] IS NOT NULL THEN
excluded_cols = TG_ARGV[1]::text[];
END IF;
IF (TG_OP = ''UPDATE'' AND TG_LEVEL = ''ROW'') THEN
audit_row.row_data = hstore(OLD.*) - excluded_cols;
audit_row.changed_fields = (hstore(NEW.*) - audit_row.row_data) - excluded_cols;
IF audit_row.changed_fields = hstore('''') THEN
-- All changed fields are ignored. Skip this update.
RETURN NULL;
END IF;
ELSIF (TG_OP = ''DELETE'' AND TG_LEVEL = ''ROW'') THEN
audit_row.row_data = hstore(OLD.*) - excluded_cols;
ELSIF (TG_OP = ''INSERT'' AND TG_LEVEL = ''ROW'') THEN
audit_row.row_data = hstore(NEW.*) - excluded_cols;
ELSIF (TG_LEVEL = ''STATEMENT'' AND TG_OP IN (''INSERT'',''UPDATE'',''DELETE'',''TRUNCATE'')) THEN
audit_row.statement_only = ''t'';
ELSE
RAISE EXCEPTION ''[audit.if_modified_func] - Trigger func added as trigger for unhandled case: %%, %%'',TG_OP, TG_LEVEL;
RETURN NULL;
END IF;
INSERT INTO audit.'|| quote_ident(TG_TABLE_NAME::TEXT) ||' VALUES (audit_row.*);
RETURN null;
END;
$$
LANGUAGE plpgsql;
ALTER FUNCTION audit.if_modified_func()
OWNER TO postgres;';
FOR i in 1..array_upper(table_names, 1) LOOP
EXECUTE format('
DROP TABLE IF EXISTS audit.%1$s;
CREATE TABLE audit.%1$s (
event_id bigserial primary key,
schema_name text not null,
table_name text not null,
relid oid not null,
session_user_name text,
action_tstamp_tx TIMESTAMP WITH TIME ZONE NOT NULL,
action_tstamp_stm TIMESTAMP WITH TIME ZONE NOT NULL,
action_tstamp_clk TIMESTAMP WITH TIME ZONE NOT NULL,
transaction_id bigint,
application_name text,
client_addr inet,
client_port integer,
client_query text,
action TEXT NOT NULL CHECK (action IN (''I'',''D'',''U'', ''T'')),
row_data hstore,
changed_fields hstore,
statement_only boolean not null
);
REVOKE ALL ON audit.%1$s FROM public;
COMMENT ON TABLE audit.%1$s IS ''History of auditable actions on audited tables, from audit.if_modified_func()'';
COMMENT ON COLUMN audit.%1$s.event_id IS ''Unique identifier for each auditable event'';
COMMENT ON COLUMN audit.%1$s.schema_name IS ''Database schema audited table for this event is in'';
COMMENT ON COLUMN audit.%1$s.table_name IS ''Non-schema-qualified table name of table event occured in'';
COMMENT ON COLUMN audit.%1$s.relid IS ''Table OID. Changes with drop/create. Get with ''''tablename''''::regclass'';
COMMENT ON COLUMN audit.%1$s.session_user_name IS ''Login / session user whose statement caused the audited event'';
COMMENT ON COLUMN audit.%1$s.action_tstamp_tx IS ''Transaction start timestamp for tx in which audited event occurred'';
COMMENT ON COLUMN audit.%1$s.action_tstamp_stm IS ''Statement start timestamp for tx in which audited event occurred'';
COMMENT ON COLUMN audit.%1$s.action_tstamp_clk IS ''Wall clock time at which audited event''''s trigger call occurred'';
COMMENT ON COLUMN audit.%1$s.transaction_id IS ''Identifier of transaction that made the change. May wrap, but unique paired with action_tstamp_tx.'';
COMMENT ON COLUMN audit.%1$s.client_addr IS ''IP address of client that issued query. Null for unix domain socket.'';
COMMENT ON COLUMN audit.%1$s.client_port IS ''Remote peer IP port address of client that issued query. Undefined for unix socket.'';
COMMENT ON COLUMN audit.%1$s.client_query IS ''Top-level query that caused this auditable event. May be more than one statement.'';
COMMENT ON COLUMN audit.%1$s.application_name IS ''Application name set when this audit event occurred. Can be changed in-session by client.'';
COMMENT ON COLUMN audit.%1$s.action IS ''Action type; I = insert, D = delete, U = update, T = truncate'';
COMMENT ON COLUMN audit.%1$s.row_data IS ''Record value. Null for statement-level trigger. For INSERT this is the new tuple. For DELETE and UPDATE it is the old tuple.'';
COMMENT ON COLUMN audit.%1$s.changed_fields IS ''New values of fields changed by UPDATE. Null except for row-level UPDATE events.'';
COMMENT ON COLUMN audit.%1$s.statement_only IS ''''''t'''' if audit event is from an FOR EACH STATEMENT trigger, ''''f'''' for FOR EACH ROW'';
CREATE INDEX %1$s_relid_idx ON audit.%1$s(relid);
CREATE INDEX %1$s_action_tstamp_tx_stm_idx ON audit.%1$s(action_tstamp_stm);
CREATE INDEX %1$s_action_idx ON audit.%1$s(action);
', table_names[i]);
EXECUTE format('
DROP TRIGGER IF EXISTS audit_trigger_row ON %1$s;
CREATE TRIGGER audit_trigger_row
AFTER INSERT OR UPDATE OR DELETE
ON public.%1$s
FOR EACH ROW
EXECUTE PROCEDURE audit.if_modified_func();', table_names[i]);
EXECUTE format('
DROP TRIGGER IF EXISTS audit_trigger_stm ON %1$s;
CREATE TRIGGER audit_trigger_stm
AFTER TRUNCATE
ON public.%1$s
FOR EACH STATEMENT
EXECUTE PROCEDURE audit.if_modified_func();', table_names[i]);
END LOOP;
RETURN 'SUCCESS';
END;
$BODY$
LANGUAGE plpgsql;
ALTER FUNCTION audit.create_audit_table(character varying[])
OWNER TO postgres;
更新03/31：
好吧，所以我创建了没有动态sql的if_modified_func()函数，我将audit_row声明为audit_row RECORD;我不确定“在插入值时需要强制转换”的部分。我也不确定这是否是插入的正确方法
EXECUTE format($string$INSERT INTO audit.%1$s VALUES (audit_row.*);$string$, TG_TABLE_NAME::text);
当我运行select audit.create_audit_table(ARRAY['organization'])时，我现在收到此错误
错误：
ERROR: record "audit_row" has no field "row_data"
CONTEXT: PL/pgSQL function audit.if_modified_func() line 42 at assignment
这是更新的功能：
CREATE OR REPLACE FUNCTION audit.if_modified_func() RETURNS TRIGGER AS $$
DECLARE
audit_row RECORD;
include_values boolean;
log_diffs boolean;
h_old hstore;
h_new hstore;
excluded_cols text[] = ARRAY[]::text[];
BEGIN
IF TG_WHEN <> 'AFTER' THEN
RAISE EXCEPTION 'audit.if_modified_func() may only run as an AFTER trigger';
END IF;
audit_row = ROW(
nextval(format('audit.%1$s_event_id_seq',TG_TABLE_NAME::text)), -- event_id
TG_TABLE_SCHEMA::text, -- schema_name
TG_TABLE_NAME::text, -- table_name
TG_RELID, -- relation OID for much quicker searches
session_user::text, -- session_user_name
current_timestamp, -- action_tstamp_tx
statement_timestamp(), -- action_tstamp_stm
clock_timestamp(), -- action_tstamp_clk
txid_current(), -- transaction ID
current_setting('application_name'), -- client application
inet_client_addr(), -- client_addr
inet_client_port(), -- client_port
current_query(), -- top-level query or queries (if multistatement) from client
substring(TG_OP,1,1), -- action
NULL, NULL, -- row_data, changed_fields
'f' -- statement_only
);
IF NOT TG_ARGV[0]::boolean IS DISTINCT FROM 'f'::boolean THEN
audit_row.client_query = NULL;
END IF;
IF TG_ARGV[1] IS NOT NULL THEN
excluded_cols = TG_ARGV[1]::text[];
END IF;
IF (TG_OP = 'UPDATE' AND TG_LEVEL = 'ROW') THEN
audit_row.row_data = hstore(OLD.*) - excluded_cols;
audit_row.changed_fields = (hstore(NEW.*) - audit_row.row_data) - excluded_cols;
IF audit_row.changed_fields = hstore('') THEN
-- All changed fields are ignored. Skip this update.
RETURN NULL;
END IF;
ELSIF (TG_OP = 'DELETE' AND TG_LEVEL = 'ROW') THEN
audit_row.row_data = hstore(OLD.*) - excluded_cols;
ELSIF (TG_OP = 'INSERT' AND TG_LEVEL = 'ROW') THEN
audit_row.row_data = hstore(NEW.*) - excluded_cols;
ELSIF (TG_LEVEL = 'STATEMENT' AND TG_OP IN ('INSERT','UPDATE','DELETE','TRUNCATE')) THEN
audit_row.statement_only = 't';
ELSE
RAISE EXCEPTION '[audit.if_modified_func] - Trigger func added as trigger for unhandled case: %, %',TG_OP, TG_LEVEL;
RETURN NULL;
END IF;
EXECUTE format('INSERT INTO audit.%1$s VALUES (audit_row.*)', TG_TABLE_NAME::text);
RETURN null;
END;
$$
LANGUAGE plpgsql;
ALTER FUNCTION audit.if_modified_func()
OWNER TO postgres;
TG_TABLE_NAME是一个特殊的触发变量，仅在触发函数内可用。你的create_audit_table()不是触发器功能。
此外，您不断重新定义您的真实触发函数（if_modified_func()），它会使之前创建的任何触发器“无效”。
在没有动态SQL魔法的情况下创建触发器函数（动态SQL只需要向这些审计表插入值）。然后，您可以将审计逻辑添加到表中，其中包含：
CREATE TRIGGER audit_trigger_row
AFTER INSERT OR UPDATE OR DELETE
ON public.<your_table_name>
FOR EACH ROW
EXECUTE PROCEDURE <your_audit_trigger_function_name>();
你可以把这个（但只有这个 - 可能是drop if exists）放在一个函数中，以便更容易地附加这个审计逻辑。
笔记：
%ROWTYPE变量（因为你不知道确切的表。你只有它的名字）。解决方案很简单：只需使用RECORD类型（虽然插入值时需要使用强制转换）。$your_keyword$<string_value>$your_keyword$格式。可能使用format()函数而不是仅仅连接值。您的代码将更具可读性。编辑：要使用你的RECORD变量，你应该：
SELECT nextval('audit.'|| quote_ident(TG_TABLE_NAME) || '_event_id_seq') AS event_id,
TG_TABLE_SCHEMA AS schema_name,
TG_TABLE_NAME AS table_name,
TG_RELID AS relid,
session_user AS session_user_name,
current_timestamp AS action_tstamp_tx,
statement_timestamp() AS action_tstamp_stm,
clock_timestamp() AS action_tstamp_clk,
txid_current() AS transaction_id,
current_setting('application_name') AS application_name,
inet_client_addr() AS client_addr,
inet_client_port() AS client_port,
current_query() AS client_query,
substring(TG_OP, 1, 1) AS action,
NULL::hstore AS row_data,
NULL::hstore AS changed_fields,
FALSE AS statement_only
INTO audit_row;
ROW()构造函数的预定义名称。第一列的名字是f1，第二列的是f2等。
audit_row.f15 = hstore(OLD.*) - excluded_cols;
选择上述方法之一后，您应该插入如下行：
EXECUTE format('INSERT INTO audit.%1$s VALUES (($1::text::audit.%1$s).*)', quote_ident(TG_TABLE_NAME)) USING audit_row;
注意：由于text无法知道EXECUTE的实际结构，因此甚至需要施放到audit_row。
quote_ident（TG_TABLE_NAME :: TEXT）将应用必要的操作来正确引用参数作为关系名称。
我建议使用execute format('statement')而不是concatinations，例如：
t=# do $$ begin raise info '%',format('I am %I, now is %L',current_user,now()); end;$$;
INFO: I am postgres, now is '2017-03-30 07:33:53.579476+00'
DO
代替：
t=# do $$ begin raise info '%','I am '||quote_ident(current_user)||', now is '||quote_ident(now()::text); end;$$;
INFO: I am postgres, now is "2017-03-30 07:36:20.495887+00"
DO