你也可以使用一个免费的数据库管理工具，比如DBeaver，它允许你查看表的DDL，这里有一个例子:

如果您想一次对多个表执行此操作，则需要多次使用-t开关(我花了一些时间才弄清楚为什么逗号分隔的列表不起作用)。此外，将结果发送到外文件或管道到另一台机器上的postgres服务器也很有用

pg_dump -t table1 -t table2 database_name --schema-only > dump.sql

pg_dump -t table1 -t table2 database_name --schema-only | psql -h server_name database_name

你也可以使用一个免费的数据库管理工具，比如DBeaver，它允许你查看表的DDL，这里有一个例子:

太棒了! 我会稍微修改一下您的代码，以显示表中的所有约束，并允许在表名中使用regexp掩码。

CREATE OR REPLACE FUNCTION public.generate_create_table_statement(p_table_name character varying)
  RETURNS SETOF text AS
$BODY$
DECLARE
    v_table_ddl   text;
    column_record record;
    table_rec record;
    constraint_rec record;
    firstrec boolean;
BEGIN
    FOR table_rec IN
        SELECT c.relname FROM pg_catalog.pg_class c
            LEFT JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace
                WHERE relkind = 'r'
                AND relname~ ('^('||p_table_name||')$')
                AND n.nspname <> 'pg_catalog'
                AND n.nspname <> 'information_schema'
                AND n.nspname !~ '^pg_toast'
                AND pg_catalog.pg_table_is_visible(c.oid)
          ORDER BY c.relname
    LOOP

        FOR column_record IN 
            SELECT 
                b.nspname as schema_name,
                b.relname as table_name,
                a.attname as column_name,
                pg_catalog.format_type(a.atttypid, a.atttypmod) as column_type,
                CASE WHEN 
                    (SELECT substring(pg_catalog.pg_get_expr(d.adbin, d.adrelid) for 128)
                     FROM pg_catalog.pg_attrdef d
                     WHERE d.adrelid = a.attrelid AND d.adnum = a.attnum AND a.atthasdef) IS NOT NULL THEN
                    'DEFAULT '|| (SELECT substring(pg_catalog.pg_get_expr(d.adbin, d.adrelid) for 128)
                                  FROM pg_catalog.pg_attrdef d
                                  WHERE d.adrelid = a.attrelid AND d.adnum = a.attnum AND a.atthasdef)
                ELSE
                    ''
                END as column_default_value,
                CASE WHEN a.attnotnull = true THEN 
                    'NOT NULL'
                ELSE
                    'NULL'
                END as column_not_null,
                a.attnum as attnum,
                e.max_attnum as max_attnum
            FROM 
                pg_catalog.pg_attribute a
                INNER JOIN 
                 (SELECT c.oid,
                    n.nspname,
                    c.relname
                  FROM pg_catalog.pg_class c
                       LEFT JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace
                  WHERE c.relname = table_rec.relname
                    AND pg_catalog.pg_table_is_visible(c.oid)
                  ORDER BY 2, 3) b
                ON a.attrelid = b.oid
                INNER JOIN 
                 (SELECT 
                      a.attrelid,
                      max(a.attnum) as max_attnum
                  FROM pg_catalog.pg_attribute a
                  WHERE a.attnum > 0 
                    AND NOT a.attisdropped
                  GROUP BY a.attrelid) e
                ON a.attrelid=e.attrelid
            WHERE a.attnum > 0 
              AND NOT a.attisdropped
            ORDER BY a.attnum
        LOOP
            IF column_record.attnum = 1 THEN
                v_table_ddl:='CREATE TABLE '||column_record.schema_name||'.'||column_record.table_name||' (';
            ELSE
                v_table_ddl:=v_table_ddl||',';
            END IF;

            IF column_record.attnum <= column_record.max_attnum THEN
                v_table_ddl:=v_table_ddl||chr(10)||
                         '    '||column_record.column_name||' '||column_record.column_type||' '||column_record.column_default_value||' '||column_record.column_not_null;
            END IF;
        END LOOP;

        firstrec := TRUE;
        FOR constraint_rec IN
            SELECT conname, pg_get_constraintdef(c.oid) as constrainddef 
                FROM pg_constraint c 
                    WHERE conrelid=(
                        SELECT attrelid FROM pg_attribute
                        WHERE attrelid = (
                            SELECT oid FROM pg_class WHERE relname = table_rec.relname
                        ) AND attname='tableoid'
                    )
        LOOP
            v_table_ddl:=v_table_ddl||','||chr(10);
            v_table_ddl:=v_table_ddl||'CONSTRAINT '||constraint_rec.conname;
            v_table_ddl:=v_table_ddl||chr(10)||'    '||constraint_rec.constrainddef;
            firstrec := FALSE;
        END LOOP;
        v_table_ddl:=v_table_ddl||');';
        RETURN NEXT v_table_ddl;
    END LOOP;
END;
$BODY$
  LANGUAGE plpgsql VOLATILE
  COST 100;
ALTER FUNCTION public.generate_create_table_statement(character varying)
  OWNER TO postgres;

例如，现在您可以执行以下查询

SELECT * FROM generate_create_table_statement('.*');

结果是这样的:

CREATE TABLE public.answer (                                                                        
     id integer DEFAULT nextval('answer_id_seq'::regclass) NOT NULL,                               
     questionid integer  NOT NULL,                                                                  
     title character varying  NOT NULL,                                                             
     defaultvalue character varying  NULL,                                                          
     valuetype integer  NOT NULL,                                                                   
     isdefault boolean  NULL,                                                                       
     minval double precision  NULL,                                                                 
     maxval double precision  NULL,                                                                 
     followminmax integer DEFAULT 0 NOT NULL,                                                       
CONSTRAINT answer_pkey                                                                              
     PRIMARY KEY (id),                                                                              
CONSTRAINT answer_questionid_fkey                                                                  
     FOREIGN KEY (questionid) REFERENCES question(id) ON UPDATE RESTRICT ON DELETE RESTRICT,       
CONSTRAINT answer_valuetype_fkey                                                                   
     FOREIGN KEY (valuetype) REFERENCES answervaluetype(id) ON UPDATE RESTRICT ON DELETE RESTRICT);

对于每个用户表。

下面是对shekwi的查询稍加改进的版本。 它生成主键约束，并能够处理临时表:

with pkey as
(
    select cc.conrelid, format(E',
    constraint %I primary key(%s)', cc.conname,
        string_agg(a.attname, ', ' 
            order by array_position(cc.conkey, a.attnum))) pkey
    from pg_catalog.pg_constraint cc
        join pg_catalog.pg_class c on c.oid = cc.conrelid
        join pg_catalog.pg_attribute a on a.attrelid = cc.conrelid 
            and a.attnum = any(cc.conkey)
    where cc.contype = 'p'
    group by cc.conrelid, cc.conname
)
select format(E'create %stable %s%I\n(\n%s%s\n);\n',
    case c.relpersistence when 't' then 'temporary ' else '' end,
    case c.relpersistence when 't' then '' else n.nspname || '.' end,
    c.relname,
    string_agg(
        format(E'\t%I %s%s',
            a.attname,
            pg_catalog.format_type(a.atttypid, a.atttypmod),
            case when a.attnotnull then ' not null' else '' end
        ), E',\n'
        order by a.attnum
    ),
    (select pkey from pkey where pkey.conrelid = c.oid)) as sql
from pg_catalog.pg_class c
    join pg_catalog.pg_namespace n on n.oid = c.relnamespace
    join pg_catalog.pg_attribute a on a.attrelid = c.oid and a.attnum > 0
    join pg_catalog.pg_type t on a.atttypid = t.oid
where c.relname = :table_name
group by c.oid, c.relname, c.relpersistence, n.nspname;

使用table_name参数指定表的名称。

(注意-此解决方案不适用于PostgreSQL v12+)

我的解决方案是使用psql和-E选项登录postgres db，如下所示:

psql -E -U username -d database   

在psql中，运行以下命令查看postgres用来生成的sql 描述表语句:

-- List all tables in the schema (my example schema name is public)
\dt public.*
-- Choose a table name from above
-- For create table of one public.tablename
\d+ public.tablename  

基于运行这些描述命令后返回的sql，我能够把它们放在一起 下面是PLPGSQL函数:

CREATE OR REPLACE FUNCTION generate_create_table_statement(p_table_name varchar)
  RETURNS text AS
$BODY$
DECLARE
    v_table_ddl   text;
    column_record record;
BEGIN
    FOR column_record IN 
        SELECT 
            b.nspname as schema_name,
            b.relname as table_name,
            a.attname as column_name,
            pg_catalog.format_type(a.atttypid, a.atttypmod) as column_type,
            CASE WHEN 
                (SELECT substring(pg_catalog.pg_get_expr(d.adbin, d.adrelid) for 128)
                 FROM pg_catalog.pg_attrdef d
                 WHERE d.adrelid = a.attrelid AND d.adnum = a.attnum AND a.atthasdef) IS NOT NULL THEN
                'DEFAULT '|| (SELECT substring(pg_catalog.pg_get_expr(d.adbin, d.adrelid) for 128)
                              FROM pg_catalog.pg_attrdef d
                              WHERE d.adrelid = a.attrelid AND d.adnum = a.attnum AND a.atthasdef)
            ELSE
                ''
            END as column_default_value,
            CASE WHEN a.attnotnull = true THEN 
                'NOT NULL'
            ELSE
                'NULL'
            END as column_not_null,
            a.attnum as attnum,
            e.max_attnum as max_attnum
        FROM 
            pg_catalog.pg_attribute a
            INNER JOIN 
             (SELECT c.oid,
                n.nspname,
                c.relname
              FROM pg_catalog.pg_class c
                   LEFT JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace
              WHERE c.relname ~ ('^('||p_table_name||')$')
                AND pg_catalog.pg_table_is_visible(c.oid)
              ORDER BY 2, 3) b
            ON a.attrelid = b.oid
            INNER JOIN 
             (SELECT 
                  a.attrelid,
                  max(a.attnum) as max_attnum
              FROM pg_catalog.pg_attribute a
              WHERE a.attnum > 0 
                AND NOT a.attisdropped
              GROUP BY a.attrelid) e
            ON a.attrelid=e.attrelid
        WHERE a.attnum > 0 
          AND NOT a.attisdropped
        ORDER BY a.attnum
    LOOP
        IF column_record.attnum = 1 THEN
            v_table_ddl:='CREATE TABLE '||column_record.schema_name||'.'||column_record.table_name||' (';
        ELSE
            v_table_ddl:=v_table_ddl||',';
        END IF;

        IF column_record.attnum <= column_record.max_attnum THEN
            v_table_ddl:=v_table_ddl||chr(10)||
                     '    '||column_record.column_name||' '||column_record.column_type||' '||column_record.column_default_value||' '||column_record.column_not_null;
        END IF;
    END LOOP;

    v_table_ddl:=v_table_ddl||');';
    RETURN v_table_ddl;
END;
$BODY$
  LANGUAGE 'plpgsql' COST 100.0 SECURITY INVOKER;

下面是函数用法:

SELECT generate_create_table_statement('tablename');

下面是drop语句，如果你不想让这个函数永久保存:

DROP FUNCTION generate_create_table_statement(p_table_name varchar);