Example - Advanced SQL Engine - Teradata Database

SQL Date and Time Functions and Expressions

Product
Advanced SQL Engine
Teradata Database
Release Number
17.05
17.00
Published
June 2020
Language
English (United States)
Last Update
2021-01-24
dita:mapPath
xmd1556127764262.ditamap
dita:ditavalPath
lze1555437562152.ditaval
dita:id
B035-1211
lifecycle
previous
Product Category
Teradata Vantage™

Assume in the employee table, created by the following CREATE TABLE statement, jobdur1 and jobdur2 are derived period columns.

CREATE TABLE employee (
   eid INTEGER NOT NULL, 
   name VARCHAR(100) NOT NULL,
   deptno INTEGER NOT NULL,
   jobst1 DATE NOT NULL,
   jobend1   DATE NOT NULL,
   PERIOD FOR jobdur1(jobst1, jobend1),
   jobst2 DATE NOT NULL,
   jobend2   DATE NOT NULL,
   PERIOD FOR jobdur2(jobst2, jobend2)
   ) PRIMARY INDEX(eid);
EID Name Dept No JobSt1 JobEnd1 JobSt2 JobEnd2
1 Tom 101 DATE'2001-01-01' DATE'2004-01-01' DATE'2005-01-01' DATE'2006-01-01'
2 Rick 201 DATE'2005-01-01' DATE'2006-01-01' DATE'2001-01-01' DATE'2004-01-01'
3 Joo 301 DATE'2005-01-01' DATE'2006-01-01' DATE'2006-01-01' DATE'2007-01-01'
4 Tam 401 DATE'2001-01-01' DATE'2006-01-01' DATE'2002-01-01' DATE'2004-01-01'
5 Pat 501 DATE'2005-01-01' DATE'2007-01-01' DATE'2006-01-01' DATE'2008-01-01'
6 Jack 601 DATE'2005-01-01' DATE'2007-01-01' DATE'2007-01-01' DATE'2008-01-01'
7 Yu 701 DATE'2005-01-01' DATE'2007-01-01' DATE'2004-01-01' DATE'2005-01-01'
8 Tim 801 DATE'2005-01-01' DATE'2007-01-01' DATE'2005-01-01' DATE'2007-01-01'

In the following SQL statement, PRECEDES is used with derived period columns of the employee table:

SELECT eid, name, jobst1, jobend1, jobst2, jobend2 
FROM employee 
WHERE jobdur1 PRECEDES jobdur2;

The result is:

EID Name Dept No JobSt1 JobEnd1 JobSt2 JobEnd2
1 Tom 101 DATE'2001-01-01' DATE'2004-01-01' DATE'2005-01-01' DATE'2006-01-01'
3 Joo 301 DATE'2005-01-01' DATE'2006-01-01' DATE'2006-01-01' DATE'2007-01-01'
6 Jack 601 DATE'2005-01-01' DATE'2007-01-01' DATE'2007-01-01' DATE'2008-01-01'