Oracle PL/SQL/Date Timezone/SYSTIMESTAMP
Содержание
Display the sessions current time/timezone AND the Operating systems time/timezone in PL/SQL code block
SQL> --
SQL>
SQL>
SQL> begin
2 dbms_output.put_line("current_timestamp (session) "|| current_timestamp);
3 dbms_output.put_line("systimestamp (database) "||systimestamp);
4 end;
5 /
current_timestamp (session) 16-JUN-08 04.36.26.959000000 PM -08:00
systimestamp (database) 16-JUN-08 05.36.26.959000000 PM -07:00
PL/SQL procedure successfully completed.
SQL>
SQL> --
Get the SYSTIMESTAMP
SQL> --SYSTIMESTAMP()
SQL>
SQL> SELECT SYSTIMESTAMP FROM dual;
SYSTIMESTAMP
---------------------------------------------------------------------------
16-SEP-06 05.35.06.531000 PM -07:00
SQL>
Use systimestamp in insert statement
SQL> create table tstz
2 (c1 timestamp with time zone,
3 c2 timestamp with time zone,
4 c3 timestamp with time zone);
Table created.
SQL>
SQL>
SQL> insert into tstz (c1,c2,c3)values( systimestamp ,systimestamp ,systimestamp);
1 row created.
SQL>
SQL> select * from tstz;
C1
---------------------------------------------------------------------------
C2
---------------------------------------------------------------------------
C3
---------------------------------------------------------------------------
16-JUN-08 05.40.39.576000 PM -07:00
16-JUN-08 05.40.39.576000 PM -07:00
16-JUN-08 05.40.39.576000 PM -07:00
1 row selected.
SQL>
SQL> drop table tstz;
Table dropped.
SQL> --
Using systimestamp to do benchmark
SQL>
SQL>CREATE TABLE project (
2 pro_id NUMBER(4),
3 pro_name VARCHAR2(40),
4 budget NUMBER(9,2),
5 CONSTRAINT project_pk PRIMARY KEY (pro_id)
6 );
Table created.
SQL>
SQL>
SQL>INSERT INTO project(pro_id, pro_name, budget)VALUES (1001, "A",12345);
1 row created.
SQL>INSERT INTO project(pro_id, pro_name, budget)VALUES (1002, "ERP",23456);
1 row created.
SQL>INSERT INTO project(pro_id, pro_name, budget)VALUES (1003, "SQL",34567);
1 row created.
SQL>INSERT INTO project(pro_id, pro_name, budget)VALUES (1004, "CRM",45678);
1 row created.
SQL>INSERT INTO project(pro_id, pro_name, budget)VALUES (1005, "VPN",56789);
1 row created.
SQL>
SQL>
SQL>CREATE TABLE server_usage (
2 pro_id NUMBER(4),
3 emp_id NUMBER,
4 time_log_date DATE,
5 hours_logged NUMBER(8,2),
6 dollars_charged NUMBER(8,2),
7 CONSTRAINT server_usage_pk PRIMARY KEY (pro_id, emp_id, time_log_date)
8 );
Table created.
SQL>INSERT INTO server_usage(pro_id, emp_id, time_log_date, hours_logged, dollars_charged)
2 VALUES (1001,101,to_date("4-Apr-2004","dd-mon-yyyy"),1123,222);
1 row created.
SQL>INSERT INTO server_usage(pro_id, emp_id, time_log_date, hours_logged, dollars_charged)
2 VALUES (1002,102,to_date("4-Apr-2005","dd-mon-yyyy"),1124,223);
1 row created.
SQL>INSERT INTO server_usage(pro_id, emp_id, time_log_date, hours_logged, dollars_charged)
2 VALUES (1003,103,to_date("4-Apr-2006","dd-mon-yyyy"),1125,224);
1 row created.
SQL>INSERT INTO server_usage(pro_id, emp_id, time_log_date, hours_logged, dollars_charged)
2 VALUES (1004,104,to_date("4-Apr-2007","dd-mon-yyyy"),1126,225);
1 row created.
SQL>INSERT INTO server_usage(pro_id, emp_id, time_log_date, hours_logged, dollars_charged)
2 VALUES (1005,105,to_date("4-Apr-2008","dd-mon-yyyy"),1127,226);
1 row created.
SQL>INSERT INTO server_usage(pro_id, emp_id, time_log_date, hours_logged, dollars_charged)
2 VALUES (1001,106,to_date("4-Apr-2009","dd-mon-yyyy"),1128,227);
1 row created.
SQL>INSERT INTO server_usage(pro_id, emp_id, time_log_date, hours_logged, dollars_charged)
2 VALUES (1002,107,to_date("4-Apr-2010","dd-mon-yyyy"),1129,228);
1 row created.
SQL>
SQL>CREATE TABLE emp (
2 emp_id NUMBER,
3 ename VARCHAR2(40),
4 hire_date DATE DEFAULT sysdate,
5 end_date DATE,
6 rate NUMBER(5,2),
7 CONSTRAINT emp_pk PRIMARY KEY (emp_id)
8 );
Table created.
SQL>INSERT INTO emp(emp_id, ename, hire_date,end_date, rate)VALUES (101, "Mary", to_date("15-Nov-1961","dd-mon-yyyy"),null,169);
1 row created.
SQL>INSERT INTO emp(emp_id, ename, hire_date,end_date, rate)VALUES (102, "Tom", to_date("16-Sep-1964","dd-mon-yyyy"),to_date("5-May-2004","dd-mon-yyyy"),135);
1 row created.
SQL>INSERT INTO emp(emp_id, ename, hire_date,end_date, rate)VALUES (104, "Peter", to_date("29-Dec-1987","dd-mon-yyyy"),to_date("1-Apr-2004","dd-mon-yyyy"),99);
1 row created.
SQL>INSERT INTO emp(emp_id, ename, hire_date,end_date, rate)VALUES (105, "Mike", to_date("15-Jun-2004","dd-mon-yyyy"),null,121);
1 row created.
SQL>INSERT INTO emp(emp_id, ename, hire_date,end_date, rate)VALUES (107, "Less", to_date("2-Jan-2004","dd-mon-yyyy"),null,45);
1 row created.
SQL>INSERT INTO emp(emp_id, ename, hire_date,end_date, rate)VALUES (108, "Park", to_date("1-Mar-1994","dd-mon-yyyy"),to_date("15-Nov-2004","dd-mon-yyyy"),220);
1 row created.
SQL>INSERT INTO emp(emp_id, ename, hire_date,end_date, rate)VALUES (110, "Ink", to_date("4-Apr-2004","dd-mon-yyyy"),to_date("30-Sep-2004","dd-mon-yyyy"),84);
1 row created.
SQL>INSERT INTO emp(emp_id, ename, hire_date,end_date, rate)VALUES (111, "Tike", to_date("23-Aug-1976","dd-mon-yyyy"),null,100);
1 row created.
SQL>INSERT INTO emp(emp_id, ename, hire_date,end_date, rate)VALUES (112, "Inn", to_date("15-Nov-1961","dd-mon-yyyy"),to_date("4-Apr-2004","dd-mon-yyyy"),70);
1 row created.
SQL>INSERT INTO emp(emp_id, ename, hire_date,end_date, rate)VALUES (113, "Kate", to_date("3-Mar-2004","dd-mon-yyyy"),to_date("31-Oct-2004","dd-mon-yyyy"),300);
1 row created.
SQL>
SQL>
SQL>--Obtain the starting time
SQL>COLUMN start_time NEW_VALUE start
SQL>SELECT systimestamp(9) start_time FROM dual;
User System Privileges Page 1
START_TIME
---------------------------------------------------------------------------
26-OCT-09 11.02.43.953000000 AM -08:00
1 row selected.
SQL>
SQL>--Do some work that you want to measure
SQL>SELECT COUNT(*) FROM emp;
User System Privileges Page 1
COUNT(*)
----------
10
1 row selected.
SQL>SELECT COUNT(*) FROM project;
User System Privileges Page 1
COUNT(*)
----------
5
1 row selected.
SQL>SELECT COUNT(*) FROM server_usage;
User System Privileges Page 1
COUNT(*)
----------
7
1 row selected.
SQL>
SQL>--Grab the ending time
SQL>COLUMN end_time NEW_VALUE end
SQL>SELECT systimestamp(9) end_time FROM dual;
User System Privileges Page 1
END_TIME
---------------------------------------------------------------------------
26-OCT-09 11.02.44.313000000 AM -08:00
1 row selected.
SQL>
SQL>--Compute the elapsed time
SQL>COLUMN elapsed_time NEW_VALUE elapsed
SQL>SELECT TO_TIMESTAMP_TZ("&end")
2 - TO_TIMESTAMP_TZ("&start") elapsed_time
3 FROM dual;
User System Privileges Page 1
ELAPSED_TIME
---------------------------------------------------------------------------
+000000000 00:00:00.360000000
1 row selected.
SQL>
SQL>--Display the elapsed time
SQL>PROMPT The elapsed time for the SELECTs was: &elapsed
The elapsed time for the SELECTs was: +000000000 00:00:00.360000000
SQL>
SQL>
SQL>drop table emp;
Table dropped.
SQL>drop table project;
Table dropped.
SQL>drop table server_usage;
Table dropped.