在pgsql的psql命令里直接select输出json字段是一长串字符，这对阅读非常不友好，查了好久也没查到pgsql有格式化输出json字段的函数，只好折腾一番。

表结构如下：

pgsql=# \d test资料表 "pgsql.test"栏位 |  型别   | 修饰词
------+---------+--------id   | integer | 非空info | jsonb   | 非空
索引："test_pkey" PRIMARY KEY, btree (id)"test_info_idx" gin (info)

SELECT的格式化输出：

pgsql=# select id,replace(replace(regexp_replace(info::text , ', "' , concat(',',chr(10),chr(9),'"'),'g') ,'{' , concat('{',chr(10),chr(9))) ,'}' , concat(chr(10),'}')) as info from test;id |                             info
----+---------------------------------------------------------------1 | {                                                            +|         "a": [1, 2, 3],                                      +|         "b": [4, 5, 6]                                       +| }2 | {                                                            +|         "a": [7, 8, 9],                                      +|         "b": [10, 11, 12]                                    +| }3 | {                                                            +|         "guid": "9c36adc1-7fb5-4d5b-83b4-90356a46061a",      +|         "name": "Angela Barton",                             +|         "tags": ["enim",                                     +|         "aliquip",                                           +|         "qui"],                                              +|         "address": "178 Howard Place, Gulf, Washington, 702",+|         "company": "Magnafone",                              +|         "latitude": 19.793713,                               +|         "is_active": true,                                   +|         "longitude": 86.513373,                              +|         "registered": "2009-11-07T08:53:22 +08:00"           +| }
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为了方便今后每次调用，写成函数：

create function format_json(text) returns text as $$
select replace(replace(regexp_replace($1 , ', "' , concat(',',chr(10),chr(9),'"'),'g'),
'{' , concat('{',chr(10),chr(9))) ,'}' , concat(chr(10),'}')) as json_s;
$$ language sql;

这样看起来就简洁直观多了：

pgsql=# select id,format_json(info::text) as info from test where id=3;id |                             info
----+---------------------------------------------------------------3 | {                                                            +|         "guid": "9c36adc1-7fb5-4d5b-83b4-90356a46061a",      +|         "name": "Angela Barton",                             +|         "tags": ["enim",                                     +|         "aliquip",                                           +|         "qui"],                                              +|         "address": "178 Howard Place, Gulf, Washington, 702",+|         "company": "Magnafone",                              +|         "latitude": 19.793713,                               +|         "is_active": true,                                   +|         "longitude": 86.513373,                              +|         "registered": "2009-11-07T08:53:22 +08:00"           +| }
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