Postgres里面有一个内置的10进制转16进制的函数:to_hex(int)/to_hex(bigint)
[postgres@localhost ~]$ psql Password: psql (9.1.3) Type "help" for help. postgres=# select to_hex(9); to_hex -------- 9 (1 row) postgres=# select to_hex(17); to_hex -------- 11 (1 row) postgres=# select to_hex(31); to_hex -------- 1f (1 row) postgres=# select to_hex(255); to_hex -------- ff (1 row) postgres=# select to_hex(256); to_hex -------- 100 (1 row)2.16进制转10进制
没有内置的，参考网上的一个例子
postgres=# CREATE FUNCTION hex_to_dec(in_hex TEXT) RETURNS INT IMMUTABLE STRICT LANGUAGE sql AS $body$ SELECT CAST(CAST(('x' || CAST($1 AS text)) AS bit(8)) AS INT); $body$; CREATE FUNCTION postgres=# select hex_to_dec('1f'); hex_to_dec ------------ 31 (1 row) postgres=# select hex_to_dec('ff'); hex_to_dec ------------ 255 (1 row) postgres=# select hex_to_dec('fe'); hex_to_dec ------------ 254 (1 row) postgres=# select hex_to_dec('09'); hex_to_dec ------------ 9 (1 row) postgres=# select hex_to_dec('11'); hex_to_dec ------------ 17 (1 row)
内置的函数说明,支持输入是int或者bigint类型
to_hex(int/bigint):
| CREATE OR REPLACE FUNCTION to_hex(integer) RETURNS text AS 'to_hex32' LANGUAGE internal IMMUTABLE STRICT COST 1; ALTER FUNCTION to_hex(integer) OWNER TO postgres; COMMENT ON FUNCTION to_hex(integer) IS 'convert int4 number to hex'; CREATE OR REPLACE FUNCTION to_hex(bigint) RETURNS text AS 'to_hex64' LANGUAGE internal IMMUTABLE STRICT COST 1; ALTER FUNCTION to_hex(bigint) OWNER TO postgres; COMMENT ON FUNCTION to_hex(bigint) IS 'convert int8 number to hex'; |
