テーブルまたはビューの依存オブジェクトを見つける

Question

バックグラウンド

PostgreSQLでオブジェクトをドロップ（または置換）するときに依存関係がある場合、ドロップは失敗します（CASCADEを指定せずに）。

問題

データベースから返されるエラーメッセージには、依存オブジェクトがリストされていません。

ソリューション例

クエリは次のようになります。

SELECT * FROM information_schema i, pg_depend pd WHERE
  i.object_id = pd.object_id AND
  i.object_type = 'TABLE' AND
  i.object_schema = 'public' AND
  i.object_name = 'table_with_dependents';

objidがありません。

関連する

• http://postgresql.1045698.n5.nabble.com/information-schema-problem-td2144069.html
• http://www.alberton.info/postgresql_meta_info.html

質問

名前とタイプごとに依存オブジェクトのリストをどのように生成しますか？

Answer 1

\d+ your_table

扶養家族のリストを取得します。 Scottがコメントで述べたように、コマンドラインのpsqlで-Eオプションを使用し、上記と同じコマンドを使用して、作成されたクエリを取得できます（マニュアルをご覧ください）。この方法で、postgresはクエリを出力します

$ psql -U username -E -c '\d+ table' database

出力はかなり長いので、出力をファイルにパイプしてください。

編集これはもう機能しないように見えます...適切な解決策を見るためにenccの答えをチェックしてください！

Answer 2

提案された解決策はpostgresql 9.1.4ではうまくいきませんでした

これは働いた：

SELECT dependent_ns.nspname as dependent_schema
, dependent_view.relname as dependent_view 
, source_ns.nspname as source_schema
, source_table.relname as source_table
, pg_attribute.attname as column_name
FROM pg_depend 
JOIN pg_rewrite ON pg_depend.objid = pg_rewrite.oid 
JOIN pg_class as dependent_view ON pg_rewrite.ev_class = dependent_view.oid 
JOIN pg_class as source_table ON pg_depend.refobjid = source_table.oid 
JOIN pg_attribute ON pg_depend.refobjid = pg_attribute.attrelid 
    AND pg_depend.refobjsubid = pg_attribute.attnum 
JOIN pg_namespace dependent_ns ON dependent_ns.oid = dependent_view.relnamespace
JOIN pg_namespace source_ns ON source_ns.oid = source_table.relnamespace
WHERE 
source_ns.nspname = 'my_schema'
AND source_table.relname = 'my_table'
AND pg_attribute.attnum > 0 
AND pg_attribute.attname = 'my_column'
ORDER BY 1,2;

Answer 3

簡単な方法は次のとおりです。

begin;
drop object cascade;
rollback;

Answer 4

PostgreSQL 9.3以降では、次のビューと関数を使用して、ユーザーオブジェクトの依存関係を表示します。 https://wiki.postgresql.org/wiki/Pg_depend_display も更新しました。

/**** Usage Examples ****
-- Examine the entire object hierarchy
SELECT report.dependency_tree('');

-- Dependencies for any relations with names containing match (in regular expression)
SELECT report.dependency_tree('match');

-- Dependencies for relations person & address
SELECT report.dependency_tree('{person,address}'::text[]);

-- Dependencies for function slice
SELECT report.dependency_tree(ARRAY['slice'::regproc]);

-- Dependencies for type hstore
SELECT report.dependency_tree(ARRAY['hstore'::regtype]);

-- Dependencies for triggers by the name updated
SELECT report.dependency_tree(ARRAY(
  SELECT oid FROM pg_trigger WHERE tgname ~ 'updated'
  ));

-- Dependencies for foreign key constraint names starting with product
SELECT report.dependency_tree(ARRAY(
  SELECT oid FROM pg_constraint
  WHERE conname ~ '^product.*_fk'
  ));
*/

DROP VIEW IF EXISTS report.dependency;
CREATE OR REPLACE VIEW report.dependency AS
WITH RECURSIVE preference AS (
  SELECT 10 AS max_depth
    , 16384 AS min_oid -- user objects only
    , '^(londiste|pgq|pg_toast)'::text AS schema_exclusion
    , '^pg_(conversion|language|ts_(dict|template))'::text AS class_exclusion
    , '{"SCHEMA":"00", "TABLE":"01", "TABLE CONSTRAINT":"02", "DEFAULT VALUE":"03",
        "INDEX":"05", "SEQUENCE":"06", "TRIGGER":"07", "FUNCTION":"08",
        "VIEW":"10", "MATERIALIZED VIEW":"11", "FOREIGN TABLE":"12"}'::json AS type_sort_orders
)
, dependency_pair AS (
    SELECT objid
      , array_agg(objsubid ORDER BY objsubid) AS objsubids
      , upper(obj.type) AS object_type
      , coalesce(obj.schema, substring(obj.identity, E'(\\w+?)\\.'), '') AS object_schema
      , obj.name AS object_name
      , obj.identity AS object_identity
      , refobjid
      , array_agg(refobjsubid ORDER BY refobjsubid) AS refobjsubids
      , upper(refobj.type) AS refobj_type
      , coalesce(CASE WHEN refobj.type='schema' THEN refobj.identity
                                                ELSE refobj.schema END
          , substring(refobj.identity, E'(\\w+?)\\.'), '') AS refobj_schema
      , refobj.name AS refobj_name
      , refobj.identity AS refobj_identity
      , CASE deptype
            WHEN 'n' THEN 'normal'
            WHEN 'a' THEN 'automatic'
            WHEN 'i' THEN 'internal'
            WHEN 'e' THEN 'extension'
            WHEN 'p' THEN 'pinned'
        END AS dependency_type
    FROM pg_depend dep
      , LATERAL pg_identify_object(classid, objid, 0) AS obj
      , LATERAL pg_identify_object(refclassid, refobjid, 0) AS refobj
      , preference
    WHERE deptype = ANY('{n,a}')
    AND objid >= preference.min_oid
    AND (refobjid >= preference.min_oid OR refobjid = 2200) -- need public schema as root node
    AND coalesce(obj.schema, substring(obj.identity, E'(\\w+?)\\.'), '') !~ preference.schema_exclusion
    AND coalesce(CASE WHEN refobj.type='schema' THEN refobj.identity
                                                ELSE refobj.schema END
          , substring(refobj.identity, E'(\\w+?)\\.'), '') !~ preference.schema_exclusion
    GROUP BY objid, obj.type, obj.schema, obj.name, obj.identity
      , refobjid, refobj.type, refobj.schema, refobj.name, refobj.identity, deptype
)
, dependency_hierarchy AS (
    SELECT DISTINCT
        0 AS level,
        refobjid AS objid,
        refobj_type AS object_type,
        refobj_identity AS object_identity,
        --refobjsubids AS objsubids,
        NULL::text AS dependency_type,
        ARRAY[refobjid] AS dependency_chain,
        ARRAY[concat(preference.type_sort_orders->>refobj_type,refobj_type,':',refobj_identity)] AS dependency_sort_chain
    FROM dependency_pair root
    , preference
    WHERE NOT EXISTS
       (SELECT 'x' FROM dependency_pair branch WHERE branch.objid = root.refobjid)
    AND refobj_schema !~ preference.schema_exclusion
    UNION ALL
    SELECT
        level + 1 AS level,
        child.objid,
        child.object_type,
        child.object_identity,
        --child.objsubids,
        child.dependency_type,
        parent.dependency_chain || child.objid,
        parent.dependency_sort_chain || concat(preference.type_sort_orders->>child.object_type,child.object_type,':',child.object_identity)
    FROM dependency_pair child
    JOIN dependency_hierarchy parent ON (parent.objid = child.refobjid)
    , preference
    WHERE level < preference.max_depth
    AND child.object_schema !~ preference.schema_exclusion
    AND child.refobj_schema !~ preference.schema_exclusion
    AND NOT (child.objid = ANY(parent.dependency_chain)) -- prevent circular referencing
)
SELECT * FROM dependency_hierarchy
ORDER BY dependency_chain ;

-- Procedure to report depedency tree using regexp search pattern (relation-only)
CREATE OR REPLACE FUNCTION report.dependency_tree(search_pattern text)
  RETURNS TABLE(dependency_tree text)
  SECURITY DEFINER LANGUAGE SQL
  AS $function$
WITH target AS (
  SELECT objid, dependency_chain
  FROM report.dependency
  WHERE object_identity ~ search_pattern
)
, list AS (
  SELECT
    format('%*s%s %s', -4*level
          , CASE WHEN object_identity ~ search_pattern THEN '*' END
          , object_type, object_identity
    ) AS dependency_tree
  , dependency_sort_chain
  FROM target
  JOIN report.dependency report
    ON report.objid = ANY(target.dependency_chain) -- root-bound chain
    OR target.objid = ANY(report.dependency_chain) -- leaf-bound chain
  WHERE length(search_pattern) > 0
  -- Do NOT waste search time on blank/null search_pattern.
  UNION
  -- Query the entire dependencies instead.
  SELECT
    format('%*s%s %s', 4*level, '', object_type, object_identity) AS depedency_tree
  , dependency_sort_chain
  FROM report.dependency
  WHERE length(coalesce(search_pattern,'')) = 0
)
SELECT dependency_tree FROM list
ORDER BY dependency_sort_chain;
$function$ ;

-- Procedure to report depedency tree by specific relation name(s) (in text array)
CREATE OR REPLACE FUNCTION report.dependency_tree(object_names text[])
  RETURNS TABLE(dependency_tree text)
  SECURITY DEFINER LANGUAGE SQL
  AS $function$
WITH target AS (
  SELECT objid, dependency_chain
  FROM report.dependency
  JOIN unnest(object_names) AS target(objname) ON objid = objname::regclass
)
, list AS (
  SELECT DISTINCT
    format('%*s%s %s', -4*level
          , CASE WHEN object_identity = ANY(object_names) THEN '*' END
          , object_type, object_identity
    ) AS dependency_tree
  , dependency_sort_chain
  FROM target
  JOIN report.dependency report
    ON report.objid = ANY(target.dependency_chain) -- root-bound chain
    OR target.objid = ANY(report.dependency_chain) -- leaf-bound chain
)
SELECT dependency_tree FROM list
ORDER BY dependency_sort_chain;
$function$ ;

-- Procedure to report depedency tree by oid
CREATE OR REPLACE FUNCTION report.dependency_tree(object_ids oid[])
  RETURNS TABLE(dependency_tree text)
  SECURITY DEFINER LANGUAGE SQL
  AS $function$
WITH target AS (
  SELECT objid, dependency_chain
  FROM report.dependency
  JOIN unnest(object_ids) AS target(objid) USING (objid)
)
, list AS (
  SELECT DISTINCT
    format('%*s%s %s', -4*level
          , CASE WHEN report.objid = ANY(object_ids) THEN '*' END
          , object_type, object_identity
    ) AS dependency_tree
  , dependency_sort_chain
  FROM target
  JOIN report.dependency report
    ON report.objid = ANY(target.dependency_chain) -- root-bound chain
    OR target.objid = ANY(report.dependency_chain) -- leaf-bound chain
)
SELECT dependency_tree FROM list
ORDER BY dependency_sort_chain;
$function$ ;

Answer 5

次のように、ネストされたビューをクエリに含めます。

WITH RECURSIVE view_deps AS (
SELECT DISTINCT dependent_ns.nspname as dependent_schema
, dependent_view.relname as dependent_view
, source_ns.nspname as source_schema
, source_table.relname as source_table
FROM pg_depend
JOIN pg_rewrite ON pg_depend.objid = pg_rewrite.oid
JOIN pg_class as dependent_view ON pg_rewrite.ev_class = dependent_view.oid
JOIN pg_class as source_table ON pg_depend.refobjid = source_table.oid
JOIN pg_namespace dependent_ns ON dependent_ns.oid = dependent_view.relnamespace
JOIN pg_namespace source_ns ON source_ns.oid = source_table.relnamespace
WHERE NOT (dependent_ns.nspname = source_ns.nspname AND dependent_view.relname = source_table.relname)
UNION
SELECT DISTINCT dependent_ns.nspname as dependent_schema
, dependent_view.relname as dependent_view
, source_ns.nspname as source_schema
, source_table.relname as source_table
FROM pg_depend
JOIN pg_rewrite ON pg_depend.objid = pg_rewrite.oid
JOIN pg_class as dependent_view ON pg_rewrite.ev_class = dependent_view.oid
JOIN pg_class as source_table ON pg_depend.refobjid = source_table.oid
JOIN pg_namespace dependent_ns ON dependent_ns.oid = dependent_view.relnamespace
JOIN pg_namespace source_ns ON source_ns.oid = source_table.relnamespace
INNER JOIN view_deps vd
    ON vd.dependent_schema = source_ns.nspname
    AND vd.dependent_view = source_table.relname
    AND NOT (dependent_ns.nspname = vd.dependent_schema AND dependent_view.relname = vd.dependent_view)
)

SELECT *
FROM view_deps
ORDER BY source_schema, source_table;

特定のテーブル属性に関心がある場合は、これを再帰CTEの上部に追加します。

JOIN pg_attribute ON pg_depend.refobjid = pg_attribute.attrelid 
    AND pg_depend.refobjsubid = pg_attribute.attnum 
...
WHERE 
source_ns.nspname = 'my_schema'
AND source_table.relname = 'my_table'
AND pg_attribute.attnum > 0 
AND pg_attribute.attname = 'my_column'

Answer 6

pg_constraintにはデータベース内のすべての制約が含まれます。すべての外部キー制約からoidおよびconfrelidを使用して、従属テーブルのconrelidをリストできます。

クエリは次のようになります

select confrelid,conrelid from pg_constraint where contype='f';