TIMESTAMPN(N) WITH LOCAL TIMEZONE数据类型转换

--TYPE#=231为TIMESTAMP(N) WITH LOCAL TIME ZONE，181为TIMESTAMP(N) WITH TIME ZONE
select u.name || '.' || o.name || '.' || c.name TSLTZcolumn
from sys.obj$ o, sys.col$ c, sys.user$ u
where c.type#=231 and o.obj#=c.obj# and u.user#=o.owner#;
------------------------------------
--某时区和 UTC 之间的差值
SELECT TZ_OFFSET('US/Eastern') FROM DUAL;
SELECT TZ_OFFSET(DBTIMEZONE) FROM DUAL;
SELECT TZ_OFFSET(SESSIONTIMEZONE) FROM DUAL;
SELECT TZ_OFFSET('-11:11') FROM DUAL
--数据库时区
SELECT DBTIMEZONE FROM DUAL;
--会话时区
SELECT SESSIONTIMEZONE FROM DUAL;
------------------------------------
--TIMESTAMP(N) WITH TIME ZONE TIMESTAMP(N) WITH LOCAL TIME ZONE 存储格式及引擎 sql引擎
--TO_TIMESTAMP_TZ函数 时的12和24进度 最小精度为纳秒
--AM/PM都可以转换得到下午,此时HH12为12进度(由上午、下午和格式中的AM/PM限制)且此时可以忽略TZR时区格式而只指定AM/PM
--TO_TIMESTAMP_TZ得到的数据类型用TO_CHAR转换时，12和24进度都可以指定AM/PM格式，反之只有12进度可以指定
--不含时区 12进度 得到默认时区 必须写上午和下午否则只能得到上午的值
SELECT TO_TIMESTAMP_TZ(TO_CHAR(TO_TIMESTAMP_TZ('2018-01-01 11:11:11.111222333 下午','YYYY-MM-DD HH12:MI:SS.FF9 AM TZR'),'YYYY-MM-DD HH12:MI:SS.FF9 AM TZR'),'YYYY-MM-DD HH12:MI:SS.FF9 AM TZR') FROM DUAL;
SELECT TO_TIMESTAMP_TZ(TO_CHAR(TO_TIMESTAMP_TZ('2018-01-01 11:11:11.111222333 下午','YYYY-MM-DD HH12:MI:SS.FF9 PM TZR'),'YYYY-MM-DD HH12:MI:SS.FF9 PM TZR'),'YYYY-MM-DD HH12:MI:SS.FF9 PM TZR') FROM DUAL;
--含时区 12进度 得到存储时区 必须写上午和下午否则只能得到上午的值
SELECT TO_TIMESTAMP_TZ(TO_CHAR(TO_TIMESTAMP_TZ('2018-01-01 11:11:11.111222333 下午 +01:00','YYYY-MM-DD HH12:MI:SS.FF9 AM TZR'),'YYYY-MM-DD HH12:MI:SS.FF9 AM TZR'),'YYYY-MM-DD HH12:MI:SS.FF9 AM TZR') FROM DUAL;
SELECT TO_TIMESTAMP_TZ(TO_CHAR(TO_TIMESTAMP_TZ('2018-01-01 11:11:11.111222333 下午 +01:00','YYYY-MM-DD HH12:MI:SS.FF9 PM TZR'),'YYYY-MM-DD HH12:MI:SS.FF9 PM TZR'),'YYYY-MM-DD HH12:MI:SS.FF9 PM TZR') FROM DUAL;

--24进度(转换格式中不需要指定对应12进度的AM/PM)，自动转换出上午、下午和时区
SELECT TO_TIMESTAMP_TZ(TO_CHAR(TO_TIMESTAMP_TZ('2018-01-01 22:11:11.111222333','YYYY-MM-DD HH24:MI:SS.FF9 TZR'),'YYYY-MM-DD HH24:MI:SS.FF9 TZR'),'YYYY-MM-DD HH24:MI:SS.FF9 TZR') FROM DUAL;
--24进度(转换格式中不需要指定对应12进度的AM/PM)，自动转换出上午、下午和指定的时区
SELECT TO_TIMESTAMP_TZ(TO_CHAR(TO_TIMESTAMP_TZ('2018-01-01 22:11:11.111222333 +01:00','YYYY-MM-DD HH24:MI:SS.FF9 TZR'),'YYYY-MM-DD HH24:MI:SS.FF9 TZR'),'YYYY-MM-DD HH24:MI:SS.FF9 TZR') FROM DUAL;
-------------------------------------
--若转换与存储引擎中存储格式一致的数据(若数据库的sql引擎支持TO_CHAR且不指定格式,因为转化格式无中文的匹配模式)，若不指定格式但数据库sql引擎支持此写法则可以这么些
SELECT TO_TIMESTAMP_TZ(TO_CHAR(TO_TIMESTAMP_TZ('01-1月-18 11:11:11.111222333 下午 +01:00'))),TO_TIMESTAMP_TZ('01-1月-18 11:11:11.111222333 下午 +01:00') FROM DUAL;
SELECT TO_TIMESTAMP_TZ(TO_CHAR(TO_TIMESTAMP_TZ('01-1月-18 11:11:11.111222333 下午'))),TO_TIMESTAMP_TZ('01-1月-18 11:11:11.111222333 下午') FROM DUAL;
-------------------------------------
--开发案例，TO_CHAR后拼接得到时区差的TIMESTAMP(N) WITH LOCAL TIME ZONE数据类型的session(模拟时区)对应值
--亚秒级的精度丢失解决方案 最小精度为纳秒
SELECT SESSIONTIMEZONE,DBTIMEZONE,SYSTIMESTAMP,
SYSTIMESTAMP+(SUBSTR(SESSIONTIMEZONE,2,2)+SUBSTR(SESSIONTIMEZONE,5,2)/60-SUBSTR(DBTIMEZONE,2,2)-SUBSTR(DBTIMEZONE,2,2)/60)/24 FROM DUAL;
--逻辑
SELECT SYSTIMESTAMP,
TO_TIMESTAMP_TZ(TO_CHAR(SYSTIMESTAMP+SUBSTR(SESSIONTIMEZONE,2,2)/24+SUBSTR(SESSIONTIMEZONE,5,2)/24/60-SUBSTR(DBTIMEZONE,2,2)/24-SUBSTR(DBTIMEZONE,5,2)/24/60,'YYYY-MM-DD HH24:MI:SS')||SUBSTR(TO_CHAR(SYSTIMESTAMP,'YYYY-MM-DD HH24:MI:SS.FF6 TZR'),20),'YYYY-MM-DD HH24:MI:SS.FF6 TZR') FROM DUAL;

--CREATE TABLE
DROP TABLE VI.A34;

CREATE TABLE A34 (
ID NUMBER,
NAME VARCHAR2(200) DEFAULT 'ABC' NOT NULL,
V_TIMESTAMP_N TIMESTAMP(9) WITH TIME ZONE DEFAULT TO_TIMESTAMP('2018-01-01 10:10:10.111222333','YYYY-MM-DD HH24:MI:SS.FF9') NOT NULL,
V_TIMESTAMP_LOCAL TIMESTAMP(9) WITH LOCAL TIME ZONE DEFAULT TO_TIMESTAMP('2018-01-01 10:10:10.111222333','YYYY-MM-DD HH24:MI:SS.FF9') NOT NULL
);
ALTER TABLE A34 ADD CONSTRAINT PK_A34 PRIMARY KEY(ID);

--写入的TIMESTAMP(N) WITH LOCAL TIME ZONE数据类型数据保持不变
DECLARE
V_SESSIONTIME_SET VARCHAR2(200);
BEGIN
V_SESSIONTIME_SET:='''+'||LPAD(TO_CHAR(TO_NUMBER(SUBSTR(DBTIMEZONE,2,2)+0)),2,0)||':'||LPAD(TO_CHAR(TO_NUMBER(SUBSTR(DBTIMEZONE,5,2))+0),2,0)||'''';
DBMS_OUTPUT.put_line(V_SESSIONTIME_SET);
EXECUTE IMMEDIATE 'ALTER SESSION SET TIME_ZONE='||V_SESSIONTIME_SET;
END;
/

DELETE FROM VI.A34;
INSERT INTO A34(ID,NAME) SELECT 1,'AB1' FROM DUAL;
INSERT INTO A34(ID,NAME) SELECT 2,'AB2' FROM DUAL;
INSERT INTO A34(ID,NAME) SELECT 3,'AB3' FROM DUAL;
COMMIT;

SELECT SESSIONTIMEZONE,DBTIMEZONE,SYSDATE,T.* FROM VI.A34 T;

--CREATE FUUNCTION
--不启用RESULT_CACHE,若启用则结果集缓存与参数一一对应
--用于客户端查询，转换结果返回TO_TIMESTAMP的数据类型
CREATE OR REPLACE FUNCTION GET_TS_TZ_INC_CLIENT(
V_OWNER VARCHAR2,
V_TABLE_NAME VARCHAR2,
V_COL_NAME VARCHAR2,
V_INPUT VARCHAR2
)
RETURN VARCHAR2 /*RESULT_CACHE*/ AS
PRAGMA AUTONOMOUS_TRANSACTION;
N_DATA_SCALE NUMBER;
V_SQL_EXE_TEMP VARCHAR2(1000);
BEGIN
BEGIN
SELECT T.DATA_SCALE INTO N_DATA_SCALE FROM DBA_TAB_COLUMNS T WHERE T.OWNER=V_OWNER AND T.TABLE_NAME=V_TABLE_NAME AND T.COLUMN_NAME=V_COL_NAME;
SELECT
'TO_TIMESTAMP(TO_CHAR('||'TO_TIMESTAMP('||'SUBSTR('||V_INPUT||',1,20+'||N_DATA_SCALE||')'||',''YYYY-MM-DD HH24:MI:SS.FF'||N_DATA_SCALE||''')'||'+(SUBSTR('||'SESSIONTIMEZONE'||',2,2)+SUBSTR('||'SESSIONTIMEZONE'||',5,2)/60-SUBSTR('||'DBTIMEZONE'||',2,2)-SUBSTR('||'DBTIMEZONE'||',2,2)/60)/24,''YYYY-MM-DD HH24:MI:SS'')
||SUBSTR('||V_INPUT||',20,20+'||N_DATA_SCALE||'),''YYYY-MM-DD HH24:MI:SS.FF'||N_DATA_SCALE||''')'
INTO V_SQL_EXE_TEMP
FROM DUAL;
EXCEPTION WHEN OTHERS THEN
DBMS_OUTPUT.PUT_LINE(SQLCODE||'--'||SQLERRM||':'||CHR(10)||V_SQL_EXE_TEMP);
RAISE_APPLICATION_ERROR(-20010,SQLCODE||'--'||SQLERRM||':'||CHR(10)||V_SQL_EXE_TEMP);
END;
RETURN V_SQL_EXE_TEMP;
END GET_TS_TZ_INC_CLIENT;
/

--用于服务端查询，转换结果返回TO_CHAR的数据类型
CREATE OR REPLACE FUNCTION GET_TS_TZ_INC_SERVER(
V_OWNER VARCHAR2,
V_TABLE_NAME VARCHAR2,
V_COL_NAME VARCHAR2,
V_INPUT VARCHAR2
)
RETURN VARCHAR2 /*RESULT_CACHE*/ AS
PRAGMA AUTONOMOUS_TRANSACTION;
N_DATA_SCALE NUMBER;
V_SQL_EXE_TEMP VARCHAR2(1000);
BEGIN
BEGIN
SELECT T.DATA_SCALE INTO N_DATA_SCALE FROM DBA_TAB_COLUMNS T WHERE T.OWNER=V_OWNER AND T.TABLE_NAME=V_TABLE_NAME AND T.COLUMN_NAME=V_COL_NAME;
SELECT
'TO_CHAR('||'TO_TIMESTAMP('||'SUBSTR('||V_INPUT||',1,20+'||N_DATA_SCALE||')'||',''YYYY-MM-DD HH24:MI:SS.FF'||N_DATA_SCALE||''')'||'+(SUBSTR('||'DBTIMEZONE'||',2,2)+SUBSTR('||'DBTIMEZONE'||',5,2)/60-SUBSTR('||'SESSIONTIMEZONE'||',2,2)-SUBSTR('||'SESSIONTIMEZONE'||',5,2)/60)/24,''YYYY-MM-DD HH24:MI:SS'')
||SUBSTR('||V_INPUT||',20,20+'||N_DATA_SCALE||')'
INTO V_SQL_EXE_TEMP
FROM DUAL;
EXCEPTION WHEN OTHERS THEN
DBMS_OUTPUT.PUT_LINE(SQLCODE||'--'||SQLERRM||':'||CHR(10)||V_SQL_EXE_TEMP);
RAISE_APPLICATION_ERROR(-20010,SQLCODE||'--'||SQLERRM||':'||CHR(10)||V_SQL_EXE_TEMP);
END;
RETURN V_SQL_EXE_TEMP;
END GET_TS_TZ_INC_SERVER;
/

--验证函数
select SESSIONTIMEZONE,DBTIMEZONE,T.* from a34 t;
select get_ts_tz_inc_client('VI','A34','V_TIMESTAMP_LOCAL','''2018-01-01 12:12:12.111222999''') from dual;
select get_ts_tz_inc_SERVER('VI','A34','V_TIMESTAMP_LOCAL','''2018-01-01 12:12:12.111222999''') from dual;

--SCRIPT TEST
--CLIENT READ
SELECT * FROM VI.A34 T;

SELECT SESSIONTIMEZONE,DBTIMEZONE,'''+'||LPAD(TO_CHAR(TO_NUMBER(SUBSTR(DBTIMEZONE,2,2)+1)),2,0)||':'||LPAD(TO_CHAR(TO_NUMBER(SUBSTR(DBTIMEZONE,5,2))+10),2,0)||'''' FROM DUAL;
--动态sql不能再ddl中赋值更新
--ALTER SESSION SET TIME_ZONE='+'||LPAD(TO_CHAR(TO_NUMBER(SUBSTR(DBTIMEZONE,2,2)+1)),2,0)||':'||LPAD(TO_CHAR(TO_NUMBER(SUBSTR(DBTIMEZONE,5,2))+10),2,0)||'';
--ALTER SESSION SET TIME_ZONE='+01:10'

DECLARE
V_SESSIONTIME_SET VARCHAR2(200);
BEGIN
V_SESSIONTIME_SET:='''+'||LPAD(TO_CHAR(TO_NUMBER(SUBSTR(DBTIMEZONE,2,2)+1)),2,0)||':'||LPAD(TO_CHAR(TO_NUMBER(SUBSTR(DBTIMEZONE,5,2))+10),2,0)||'''';
DBMS_OUTPUT.put_line(V_SESSIONTIME_SET);
EXECUTE IMMEDIATE 'ALTER SESSION SET TIME_ZONE='||V_SESSIONTIME_SET;
END;
/

SELECT VI.GET_TS_TZ_INC_CLIENT('VI','A34','T_TIMESTAMP') FROM DUAL;

SELECT SESSIONTIMEZONE,DBTIMEZONE,T.T_TIMESTAMP,
TO_TIMESTAMP_TZ(TO_CHAR(T_TIMESTAMP+(SUBSTR('+01:10',2,2)+SUBSTR('+01:10',5,2)/60-SUBSTR('+00:00',2,2)-SUBSTR('+00:00',2,2)/60)/24,'YYYY-MM-DD HH24:MI:SS')
||SUBSTR(TO_CHAR(T_TIMESTAMP,'YYYY-MM-DD HH24:MI:SS.FF9 TZR'),20),'YYYY-MM-DD HH24:MI:SS.FF9 TZR')
FROM VI.A34 T;

-------------
--SERVER WRITE 输入参数为把TIMESTAMP(N)转换为VARCHAR2
SELECT VI.GET_TS_TZ_INC_SERVER('VI','A34','T_TIMESTAMP','2018-01-01 10:10:10.111222333') FROM DUAL;

SELECT SESSIONTIMEZONE,DBTIMEZONE,TO_TIMESTAMP('2018-01-01 10:10:10.111222333','YYYY-MM-DD HH24:MI:SS.FF9') AS TO_TIMESTAMP_COMPARE,
TO_TIMESTAMP_TZ(TO_CHAR(TO_TIMESTAMP('2018-01-01 10:10:10.111222333','YYYY-MM-DD HH24:MI:SS.FF9')+(SUBSTR('+00:00',2,2)+SUBSTR('+00:00',5,2)/60-SUBSTR('+01:10',2,2)-SUBSTR('+01:10',5,2)/60)/24,'YYYY-MM-DD HH24:MI:SS')
||SUBSTR(TO_CHAR(TO_TIMESTAMP('2018-01-01 10:10:10.111222333','YYYY-MM-DD HH24:MI:SS.FF9'),'YYYY-MM-DD HH24:MI:SS.FF9 TZR'),20),'YYYY-MM-DD HH24:MI:SS.FF9 TZR')
FROM DUAL;

-以下为拓展部分，当结果集缓存不完全依赖于参数时的风险需要消除
--DETERMINISTIC FUNCTION 确定性参数结果集函数
CREATE OR REPLACE FUNCTION GET_TIMESTAMP_N(
N_ID NUMBER
)
RETURN VARCHAR2 DETERMINISTIC/*RESULT_CACHE*/ AS
PRAGMA AUTONOMOUS_TRANSACTION;
V_NAME VARCHAR2(40);
BEGIN
SELECT T.NAME INTO V_NAME FROM VI.A34 T WHERE T.ID=N_ID;
RETURN V_NAME;
END GET_TIMESTAMP_N;
/

--RESULT_CACHE FUNCTION 结果集缓存函数
CREATE OR REPLACE FUNCTION GET_TIMESTAMP_N(
N_ID NUMBER
)
RETURN VARCHAR2 RESULT_CACHE AS
PRAGMA AUTONOMOUS_TRANSACTION;
V_NAME VARCHAR2(40);
BEGIN
SELECT T.NAME INTO V_NAME FROM VI.A34 T WHERE T.ID=N_ID;
RETURN V_NAME;
END GET_TIMESTAMP_N;
/