Oracle PL/SQL/Date Timezone/SYSDATE

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Adding One Month a certain date

 
SQL>
SQL> Select ADD_MONTHS(TO_DATE("31-MAR-99"),1) from DUAL;
ADD_MONTHS(TO_DATE("
--------------------
30-APR-0099 00:00:00
1 row selected.
SQL>
SQL> --



Adding Two Months to SYSDATE

 
SQL>
SQL> SELECT ADD_MONTHS(SYSDATE,2) from DUAL;
ADD_MONTHS(SYSDATE,2
--------------------
16-AUG-2008 18:08:07
1 row selected.

SQL>
SQL>
SQL> --



Combining TO_CHAR to Format SYSDATE

 
SQL>
SQL> SELECT TO_CHAR(SYSDATE,"MM/DD/YYYY HH:MM:SS AM")
  2        "Today"s Date and Time" from DUAL;
Today"s Date and Time
----------------------
06/16/2008 06:06:07 PM
1 row selected.
SQL>
SQL> --



Finding the First Monday After the Current Date and Time

 
SQL> --
SQL>
SQL> SELECT TO_CHAR(NEXT_DAY(SYSDATE,"Monday"),"MM/DD/YYYY HH:MM:SS AM")
  2       "Next_Day"
  3   from DUAL;
Next_Day
----------------------
06/23/2008 06:06:08 PM
1 row selected.
SQL>
SQL> --



Get current operating system date

SQL>
SQL> SELECT SYSDATE FROM dual;
SYSDATE
---------
30-AUG-06
SQL>
SQL>



Minus days from sysdate

 
SQL>
SQL> CREATE TABLE purchase (
  2       product_name  VARCHAR2(25),
  3       salesperson   VARCHAR2(3),
  4       purchase_date DATE,
  5       quantity      NUMBER(4,2));
Table created.
SQL>
SQL> INSERT INTO purchase VALUES ("Small Widget", 10, sysdate, "1);
ERROR:
ORA-01756: quoted string not properly terminated

SQL> INSERT INTO purchase VALUES ("Medium Widget", 15, sysdate-14, 2);
1 row created.
SQL> INSERT INTO purchase VALUES ("Round Station", 25, sysdate-7, 3);
1 row created.
SQL> INSERT INTO purchase VALUES ("Product Number", 10, sysdate+7, 4);
1 row created.
SQL>
SQL>
SQL>
SQL> DROP TABLE purchase;
Table dropped.
SQL>
SQL>



Removing the Time from SYSDATE

 
SQL>
SQL> SELECT TO_CHAR(TRUNC(SYSDATE),"MM/DD/YYYY HH:MM:SS AM")
  2      "Today"s Date and Time"
  3       from DUAL;
Today"s Date and Time
----------------------
06/16/2008 12:06:00 AM
1 row selected.
SQL> --



select sysdate

 
SQL>
SQL> select sysdate
  2  from dual
  3  /
SYSDATE
---------
16-JUN-08
1 row selected.
SQL> --



Truncating to the Quarter

 
SQL> --
SQL>
SQL> SELECT TO_CHAR(TRUNC(SYSDATE,"Q"),"MM/DD/YYYY HH:MM:SS AM")
  2      "Today"s Date and Time"
  3   from DUAL
  4
SQL> --



use sysdate to init a variable

 
SQL>
SQL> set echo on
SQL>
SQL> DECLARE
  2      v_MyChar VARCHAR2(20) := "test";
  3      v_NUMBER NUMBER;
  4      V_Date DATE := SYSDATE;
  5      v_counter INTEGER;
  6  BEGIN
  7      DBMS_OUTPUT.PUT_LINE("This is a Test");
  8      DBMS_OUTPUT.PUT_LINE("Of Syntax Error Debugging");
  9      For v_COUNTER IN 1..5 LOOP
 10          DBMS_OUTPUT.PUT_LINE("You are in loop:" || v_counter);
 11      END LOOP;
 12  END;
 13  /
This is a Test
Of Syntax Error Debugging
You are in loop:1
You are in loop:2
You are in loop:3
You are in loop:4
You are in loop:5
PL/SQL procedure successfully completed.
SQL>
SQL>
SQL>
SQL> --



Using the SYSDATE function: return the current date from the system

SQL> -- create demo table
SQL> create table Employee(
  2    ID                 VARCHAR2(4 BYTE)         NOT NULL,
  3    First_Name         VARCHAR2(10 BYTE),
  4    Last_Name          VARCHAR2(10 BYTE),
  5    Start_Date         DATE,
  6    End_Date           DATE,
  7    Salary             Number(8,2),
  8    City               VARCHAR2(10 BYTE),
  9    Description        VARCHAR2(15 BYTE)
 10  )
 11  /
Table created.
SQL>
SQL> -- prepare data
SQL> insert into Employee(ID,  First_Name, Last_Name, Start_Date,                     End_Date,                       Salary,  City,       Description)
  2               values ("01","Jason",    "Martin",  to_date("19960725","YYYYMMDD"), to_date("20060725","YYYYMMDD"), 1234.56, "Toronto",  "Programmer")
  3  /
1 row created.
SQL> insert into Employee(ID,  First_Name, Last_Name, Start_Date,                     End_Date,                       Salary,  City,       Description)
  2                values("02","Alison",   "Mathews", to_date("19760321","YYYYMMDD"), to_date("19860221","YYYYMMDD"), 6661.78, "Vancouver","Tester")
  3  /
1 row created.
SQL> insert into Employee(ID,  First_Name, Last_Name, Start_Date,                     End_Date,                       Salary,  City,       Description)
  2                values("03","James",    "Smith",   to_date("19781212","YYYYMMDD"), to_date("19900315","YYYYMMDD"), 6544.78, "Vancouver","Tester")
  3  /
1 row created.
SQL> insert into Employee(ID,  First_Name, Last_Name, Start_Date,                     End_Date,                       Salary,  City,       Description)
  2                values("04","Celia",    "Rice",    to_date("19821024","YYYYMMDD"), to_date("19990421","YYYYMMDD"), 2344.78, "Vancouver","Manager")
  3  /
1 row created.
SQL> insert into Employee(ID,  First_Name, Last_Name, Start_Date,                     End_Date,                       Salary,  City,       Description)
  2                values("05","Robert",   "Black",   to_date("19840115","YYYYMMDD"), to_date("19980808","YYYYMMDD"), 2334.78, "Vancouver","Tester")
  3  /
1 row created.
SQL> insert into Employee(ID,  First_Name, Last_Name, Start_Date,                     End_Date,                       Salary, City,        Description)
  2                values("06","Linda",    "Green",   to_date("19870730","YYYYMMDD"), to_date("19960104","YYYYMMDD"), 4322.78,"New York",  "Tester")
  3  /
1 row created.
SQL> insert into Employee(ID,  First_Name, Last_Name, Start_Date,                     End_Date,                       Salary, City,        Description)
  2                values("07","David",    "Larry",   to_date("19901231","YYYYMMDD"), to_date("19980212","YYYYMMDD"), 7897.78,"New York",  "Manager")
  3  /
1 row created.
SQL> insert into Employee(ID,  First_Name, Last_Name, Start_Date,                     End_Date,                       Salary, City,        Description)
  2                values("08","James",    "Cat",     to_date("19960917","YYYYMMDD"), to_date("20020415","YYYYMMDD"), 1232.78,"Vancouver", "Tester")
  3  /
1 row created.
SQL>
SQL>
SQL>
SQL> -- display data in the table
SQL> select * from Employee
  2  /
ID   FIRST_NAME LAST_NAME  START_DAT END_DATE      SALARY CITY       DESCRIPTION
---- ---------- ---------- --------- --------- ---------- ---------- ---------------
01   Jason      Martin     25-JUL-96 25-JUL-06    1234.56 Toronto    Programmer
02   Alison     Mathews    21-MAR-76 21-FEB-86    6661.78 Vancouver  Tester
03   James      Smith      12-DEC-78 15-MAR-90    6544.78 Vancouver  Tester
04   Celia      Rice       24-OCT-82 21-APR-99    2344.78 Vancouver  Manager
05   Robert     Black      15-JAN-84 08-AUG-98    2334.78 Vancouver  Tester
06   Linda      Green      30-JUL-87 04-JAN-96    4322.78 New York   Tester
07   David      Larry      31-DEC-90 12-FEB-98    7897.78 New York   Manager
08   James      Cat        17-SEP-96 15-APR-02    1232.78 Vancouver  Tester
8 rows selected.
SQL>
SQL>
SQL>
SQL>
SQL>
SQL>
SQL>
SQL> --Using the SYSDATE function: return the current date from the system.
SQL>
SQL> SELECT ID, Start_Date FROM Employee WHERE Start_Date < SYSDATE;
ID   START_DAT
---- ---------
01   25-JUL-96
02   21-MAR-76
03   12-DEC-78
04   24-OCT-82
05   15-JAN-84
06   30-JUL-87
07   31-DEC-90
08   17-SEP-96
8 rows selected.
SQL>
SQL>
SQL>
SQL> -- clean the table
SQL> drop table Employee
  2  /
Table dropped.
SQL>
SQL>