以防万一。。。清理Postgresql数据库的简单Python脚本

import psycopg2
import sys

# Drop all tables from a given database

try:
    conn = psycopg2.connect("dbname='akcja_miasto' user='postgres' password='postgres'")
    conn.set_isolation_level(0)
except:
    print "Unable to connect to the database."

cur = conn.cursor()

try:
    cur.execute("SELECT table_schema,table_name FROM information_schema.tables WHERE table_schema = 'public' ORDER BY table_schema,table_name")
    rows = cur.fetchall()
    for row in rows:
        print "dropping table: ", row[1]   
        cur.execute("drop table " + row[1] + " cascade") 
    cur.close()
    conn.close()        
except:
    print "Error: ", sys.exc_info()[1]

确保复制后缩进正确，因为Python依赖它。

以下步骤可能会有所帮助（对于linux用户）：

首先，通过以下命令输入postgres命令提示符：sudo-u postgres psql通过以下命令输入数据库（我的数据库名为：maoss）：\c猫现在输入删除所有表格的命令：DROP SCHEMA公共级联；CREATE SCHEMA公共；向公众授予所有计划；向公众公开所有计划；现在通过以下命令退出psql：\问

注意：我的答案是真正删除表和其他数据库对象；为了删除表中的所有数据，即截断所有表，Endre Both在一个月后提供了一个同样执行良好的（直接执行）语句。

对于不能仅删除SCHEMA public CASCADE；的情况；，由当前用户拥有；或者，这是我编写的一个独立的SQL脚本，它是事务安全的（即，您可以将它放在BEGIN和ROLLBACK之间；只测试它或COMMIT；实际执行操作），并清理“所有”数据库对象……好吧，我们的应用程序使用的或我可以明智地添加的数据库中使用的所有对象，即：

表上的触发器表上的约束（FK、PK、CHECK、UNIQUE）标记ēs视图（正常或材料化）桌子序列例程（聚合函数、函数、过程）所有nōn默认（即非公共或DB内部）模式“我们”拥有：当作为“非数据库超级用户”运行时，脚本很有用；超级用户可以删除所有模式（但真正重要的模式仍然被明确排除）扩展名（用户提供，但我通常会故意将其保留在其中）

未删除的是（有些是故意的；有些只是因为我在DB中没有示例）：

公共模式（例如，扩展提供的内容）排序规则和其他区域设置内容事件触发器文本搜索内容，…（请参阅此处了解我可能错过的其他内容）角色或其他安全设置复合类型烤面包桌FDW和外来表格

当您要还原的转储是与您要还原到的数据库不同的数据库模式版本（例如Debian dbconfig common、Flyway或Liquibase/DB Manul）时，这非常有用。

我还有一个版本，它删除了“除了两个表和属于它们的内容之外的所有内容”（一个序列，手动测试，抱歉，我知道，很无聊），以防有人感兴趣；差异很小。如果感兴趣，请联系我或查看此回购。

SQL

-- Copyright © 2019, 2020
--      mirabilos <t.glaser@tarent.de>
--
-- Provided that these terms and disclaimer and all copyright notices
-- are retained or reproduced in an accompanying document, permission
-- is granted to deal in this work without restriction, including un‐
-- limited rights to use, publicly perform, distribute, sell, modify,
-- merge, give away, or sublicence.
--
-- This work is provided “AS IS” and WITHOUT WARRANTY of any kind, to
-- the utmost extent permitted by applicable law, neither express nor
-- implied; without malicious intent or gross negligence. In no event
-- may a licensor, author or contributor be held liable for indirect,
-- direct, other damage, loss, or other issues arising in any way out
-- of dealing in the work, even if advised of the possibility of such
-- damage or existence of a defect, except proven that it results out
-- of said person’s immediate fault when using the work as intended.
-- -
-- Drop everything from the PostgreSQL database.

DO $$
DECLARE
        q TEXT;
        r RECORD;
BEGIN
        -- triggers
        FOR r IN (SELECT pns.nspname, pc.relname, pt.tgname
                FROM pg_catalog.pg_trigger pt, pg_catalog.pg_class pc, pg_catalog.pg_namespace pns
                WHERE pns.oid=pc.relnamespace AND pc.oid=pt.tgrelid
                    AND pns.nspname NOT IN ('information_schema', 'pg_catalog', 'pg_toast')
                    AND pt.tgisinternal=false
            ) LOOP
                EXECUTE format('DROP TRIGGER %I ON %I.%I;',
                    r.tgname, r.nspname, r.relname);
        END LOOP;
        -- constraints #1: foreign key
        FOR r IN (SELECT pns.nspname, pc.relname, pcon.conname
                FROM pg_catalog.pg_constraint pcon, pg_catalog.pg_class pc, pg_catalog.pg_namespace pns
                WHERE pns.oid=pc.relnamespace AND pc.oid=pcon.conrelid
                    AND pns.nspname NOT IN ('information_schema', 'pg_catalog', 'pg_toast')
                    AND pcon.contype='f'
            ) LOOP
                EXECUTE format('ALTER TABLE ONLY %I.%I DROP CONSTRAINT %I;',
                    r.nspname, r.relname, r.conname);
        END LOOP;
        -- constraints #2: the rest
        FOR r IN (SELECT pns.nspname, pc.relname, pcon.conname
                FROM pg_catalog.pg_constraint pcon, pg_catalog.pg_class pc, pg_catalog.pg_namespace pns
                WHERE pns.oid=pc.relnamespace AND pc.oid=pcon.conrelid
                    AND pns.nspname NOT IN ('information_schema', 'pg_catalog', 'pg_toast')
                    AND pcon.contype<>'f'
            ) LOOP
                EXECUTE format('ALTER TABLE ONLY %I.%I DROP CONSTRAINT %I;',
                    r.nspname, r.relname, r.conname);
        END LOOP;
        -- indicēs
        FOR r IN (SELECT pns.nspname, pc.relname
                FROM pg_catalog.pg_class pc, pg_catalog.pg_namespace pns
                WHERE pns.oid=pc.relnamespace
                    AND pns.nspname NOT IN ('information_schema', 'pg_catalog', 'pg_toast')
                    AND pc.relkind='i'
            ) LOOP
                EXECUTE format('DROP INDEX %I.%I;',
                    r.nspname, r.relname);
        END LOOP;
        -- normal and materialised views
        FOR r IN (SELECT pns.nspname, pc.relname
                FROM pg_catalog.pg_class pc, pg_catalog.pg_namespace pns
                WHERE pns.oid=pc.relnamespace
                    AND pns.nspname NOT IN ('information_schema', 'pg_catalog', 'pg_toast')
                    AND pc.relkind IN ('v', 'm')
            ) LOOP
                EXECUTE format('DROP VIEW %I.%I;',
                    r.nspname, r.relname);
        END LOOP;
        -- tables
        FOR r IN (SELECT pns.nspname, pc.relname
                FROM pg_catalog.pg_class pc, pg_catalog.pg_namespace pns
                WHERE pns.oid=pc.relnamespace
                    AND pns.nspname NOT IN ('information_schema', 'pg_catalog', 'pg_toast')
                    AND pc.relkind='r'
            ) LOOP
                EXECUTE format('DROP TABLE %I.%I;',
                    r.nspname, r.relname);
        END LOOP;
        -- sequences
        FOR r IN (SELECT pns.nspname, pc.relname
                FROM pg_catalog.pg_class pc, pg_catalog.pg_namespace pns
                WHERE pns.oid=pc.relnamespace
                    AND pns.nspname NOT IN ('information_schema', 'pg_catalog', 'pg_toast')
                    AND pc.relkind='S'
            ) LOOP
                EXECUTE format('DROP SEQUENCE %I.%I;',
                    r.nspname, r.relname);
        END LOOP;
        -- extensions (only if necessary; keep them normally)
        FOR r IN (SELECT pns.nspname, pe.extname
                FROM pg_catalog.pg_extension pe, pg_catalog.pg_namespace pns
                WHERE pns.oid=pe.extnamespace
                    AND pns.nspname NOT IN ('information_schema', 'pg_catalog', 'pg_toast')
            ) LOOP
                EXECUTE format('DROP EXTENSION %I;', r.extname);
        END LOOP;
        -- aggregate functions first (because they depend on other functions)
        FOR r IN (SELECT pns.nspname, pp.proname, pp.oid
                FROM pg_catalog.pg_proc pp, pg_catalog.pg_namespace pns, pg_catalog.pg_aggregate pagg
                WHERE pns.oid=pp.pronamespace
                    AND pns.nspname NOT IN ('information_schema', 'pg_catalog', 'pg_toast')
                    AND pagg.aggfnoid=pp.oid
            ) LOOP
                EXECUTE format('DROP AGGREGATE %I.%I(%s);',
                    r.nspname, r.proname,
                    pg_get_function_identity_arguments(r.oid));
        END LOOP;
        -- routines (functions, aggregate functions, procedures, window functions)
        IF EXISTS (SELECT * FROM pg_catalog.pg_attribute
                WHERE attrelid='pg_catalog.pg_proc'::regclass
                    AND attname='prokind' -- PostgreSQL 11+
            ) THEN
                q := 'CASE pp.prokind
                        WHEN ''p'' THEN ''PROCEDURE''
                        WHEN ''a'' THEN ''AGGREGATE''
                        ELSE ''FUNCTION''
                    END';
        ELSIF EXISTS (SELECT * FROM pg_catalog.pg_attribute
                WHERE attrelid='pg_catalog.pg_proc'::regclass
                    AND attname='proisagg' -- PostgreSQL ≤10
            ) THEN
                q := 'CASE pp.proisagg
                        WHEN true THEN ''AGGREGATE''
                        ELSE ''FUNCTION''
                    END';
        ELSE
                q := '''FUNCTION''';
        END IF;
        FOR r IN EXECUTE 'SELECT pns.nspname, pp.proname, pp.oid, ' || q || ' AS pt
                FROM pg_catalog.pg_proc pp, pg_catalog.pg_namespace pns
                WHERE pns.oid=pp.pronamespace
                    AND pns.nspname NOT IN (''information_schema'', ''pg_catalog'', ''pg_toast'')
            ' LOOP
                EXECUTE format('DROP %s %I.%I(%s);', r.pt,
                    r.nspname, r.proname,
                    pg_get_function_identity_arguments(r.oid));
        END LOOP;
        -- nōn-default schemata we own; assume to be run by a not-superuser
        FOR r IN (SELECT pns.nspname
                FROM pg_catalog.pg_namespace pns, pg_catalog.pg_roles pr
                WHERE pr.oid=pns.nspowner
                    AND pns.nspname NOT IN ('information_schema', 'pg_catalog', 'pg_toast', 'public')
                    AND pr.rolname=current_user
            ) LOOP
                EXECUTE format('DROP SCHEMA %I;', r.nspname);
        END LOOP;
        -- voilà
        RAISE NOTICE 'Database cleared!';
END; $$;

在PostgreSQL 9.6（jessie backports）上进行了测试，但后来的添加（由Clément Prévost提供的扩展）除外。9.6和12.2中测试了骨料去除，12.2中也测试了程序去除。欢迎修复错误和进一步改进！

继Pablo和LenW之后，这里有一个单行程序，它既准备又执行：

psql-U$PGUSER$PGDB-t-c“从pg_tables中选择'drop table\”'||tablename||'\“cascade；'，其中schemaname='public'”|psql-U$PGUSER$PGDB

注意：设置$PGUSER和$PGDB或将其替换为所需的值

如果安装了PL/PGSQL过程语言，则可以使用以下命令删除所有内容，而无需使用shell/Perl外部脚本。

DROP FUNCTION IF EXISTS remove_all();

CREATE FUNCTION remove_all() RETURNS void AS $$
DECLARE
    rec RECORD;
    cmd text;
BEGIN
    cmd := '';

    FOR rec IN SELECT
            'DROP SEQUENCE ' || quote_ident(n.nspname) || '.'
                || quote_ident(c.relname) || ' CASCADE;' AS name
        FROM
            pg_catalog.pg_class AS c
        LEFT JOIN
            pg_catalog.pg_namespace AS n
        ON
            n.oid = c.relnamespace
        WHERE
            relkind = 'S' AND
            n.nspname NOT IN ('pg_catalog', 'pg_toast') AND
            pg_catalog.pg_table_is_visible(c.oid)
    LOOP
        cmd := cmd || rec.name;
    END LOOP;

    FOR rec IN SELECT
            'DROP TABLE ' || quote_ident(n.nspname) || '.'
                || quote_ident(c.relname) || ' CASCADE;' AS name
        FROM
            pg_catalog.pg_class AS c
        LEFT JOIN
            pg_catalog.pg_namespace AS n
        ON
            n.oid = c.relnamespace WHERE relkind = 'r' AND
            n.nspname NOT IN ('pg_catalog', 'pg_toast') AND
            pg_catalog.pg_table_is_visible(c.oid)
    LOOP
        cmd := cmd || rec.name;
    END LOOP;

    FOR rec IN SELECT
            'DROP FUNCTION ' || quote_ident(ns.nspname) || '.'
                || quote_ident(proname) || '(' || oidvectortypes(proargtypes)
                || ');' AS name
        FROM
            pg_proc
        INNER JOIN
            pg_namespace ns
        ON
            (pg_proc.pronamespace = ns.oid)
        WHERE
            ns.nspname =
            'public'
        ORDER BY
            proname
    LOOP
        cmd := cmd || rec.name;
    END LOOP;

    EXECUTE cmd;
    RETURN;
END;
$$ LANGUAGE plpgsql;

SELECT remove_all();

我建议您将其复制到一个文件中，然后使用“--file”或“-f”选项将该文件作为输入传递给psql，而不是在“psql”提示符下键入：

psql -f clean_all_pg.sql

值得称赞的地方：我写了这个函数，但我认为这些查询（至少第一个）来自几年前pgsql邮件列表中的某个人。不记得确切的时间或哪一天。

如果您的所有表都在一个模式中，那么这种方法可以工作（下面的代码假设您的模式的名称是公共的）

DROP SCHEMA public CASCADE;
CREATE SCHEMA public;

如果您使用PostgreSQL 9.3或更高版本，您可能还需要恢复默认授权。

GRANT ALL ON SCHEMA public TO postgres;
GRANT ALL ON SCHEMA public TO public;