大壯十二 2022-07-24 00:16:18 阅读数:285
GBase 8c 數據庫提供一些字符串操作符,在這些函數裏使用關鍵字而不是逗號來分隔參數。
描述:二進制字符串中的字節數。返回值類型:int
示例:
gbase=# SELECT octet_length(E'jo\\000se'::bytea) AS RESULT;
result
--------
5
(1 row)
描述:替換子串。返回值類型:bytea
示例:
gbase=# SELECT overlay(E'Th\\000omas'::bytea placing E'\\002\\003'::bytea from 2 for 3) AS RESULT;
result
----------------
\x5402036d6173
(1 row)
示例:
gbase=# SELECT position(E'\\000om'::bytea in E'Th\\000omas'::bytea) AS RESULT;
result
--------
3
(1 row)
描述:截取子串。返回值類型:bytea
示例:
gbase=# SELECT substring(E'Th\\000omas'::bytea from 2 for 3) AS RESULT;
result
----------
\x68006f
(1 row)
描述:截取子串。返回值類型:bytea
示例:
gbase=# select substr(E'Th\\000omas'::bytea,2, 3) as result;
result
----------
\x68006f
(1 row)
描述:從string的開頭和結尾删除只包含bytes中字節的最長字符串。返回值類型:bytea
示例:
gbase=# SELECT trim(E'\\000'::bytea from E'\\000Tom\\000'::bytea) AS RESULT;
result
----------
\x546f6d
(1 row)
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