postgres=# SELECT
postgres-# *
postgres-# FROM
postgres-# (SELECT
postgres(# array_to_string(
postgres(# array_agg(
postgres(# CASE
postgres(# WHEN(
postgres(# POWER(( xx.x - 25 ) ,2 ) / 130 + POWER(( yy.y - 25 ) ,2 ) / 130
postgres(# ) = 1
postgres(# THEN '$' WHEN(
postgres(# SQRT( POWER( xx.x - 20 ,2 ) + POWER( yy.y - 20 ,2 ) )
postgres(# ) < 2
postgres(# THEN '#' WHEN(
postgres(# SQRT( POWER( xx.x - 20 ,2 ) + POWER( yy.y - 30 ,2 ) )
postgres(# ) < 2
postgres(# THEN '#' WHEN(
postgres(# SQRT( POWER( xx.x - 29 ,2 ) + POWER( yy.y - 25 ,2 ) )
postgres(# ) < 4
postgres(# THEN '#' WHEN(
postgres(# POWER(( xx.x - 10 ) ,2 ) / 40 + POWER(( yy.y - 10 ) ,2 ) / 40
postgres(# ) = 1
postgres(# THEN '$' WHEN(
postgres(# POWER(( xx.x - 10 ) ,2 ) / 40 + POWER(( yy.y - 40 ) ,2 ) / 40 = 1
postgres(# )
postgres(# THEN '$'
postgres(# ELSE ' '
postgres(# END
postgres(# ) ,
postgres(# ' '
postgres(# ) AS cartoon
postgres(# FROM
postgres(# (
postgres(# SELECT
postgres(# generate_series(
postgres(# 1 ,
postgres(# 40
postgres(# ) AS x
postgres(# ) AS xx ,
postgres(# (
postgres(# SELECT
postgres(# generate_series(
postgres(# 1 ,
postgres(# 50
postgres(# ) AS y
postgres(# ) AS yy
postgres(# GROUP BY xx.x ORDER BY xx.x
postgres(# ) AS co_ord;
cartoon
-----------------------------------------------------------------------------------------------------
$ $ $ $
$ $ $ $
$ $ $ $
$ $
$ $ $ $ $ $
$ $
# # # # # #
# # # # # #
# # # # # #
$ $
# # # # #
# # # # # # #
$ # # # # # # # $
# # # # # # #
# # # # # # #
# # # # # # #
$ # # # # # $
$ $
$ $
(40 rows)postgres=# SELECT
postgres-# *
postgres-#
阅读背景：
PostgreSQL 用SQL画一个米老鼠_weixin_34331102的博客
来源：互联网
分享到：
