offsetDate

Syntax

string|bool ADOConnection::offsetDate( 
       float $offset
       optional string $isoDate
)

Description

The function offsetDate() returns a string with the native SQL functions to calculate future and past dates based on $isoDate in a portable fashion. If $isoDate is not defined, then the current date (at 12 midnight) is used.

The function returns the SQL string that performs the calculation when passed to Execute(). The value returned when the statement is executed is an ISO Date.

The function returns false if invalid parameters are provided.

Passing a decimal offset less than one without specifying a base date will always return the current date because the calculation time basis is always the beginning of the current date

Inputs

The $offset is the number of days that should be added or subtracted from the reference date; the decimal portion is the fraction of a day (e.g. 0.5 = 12 hours)

The $isoDate can be:

A basis date in ISO format including a time portion, if a fractional calculation is required
An SQL statement that produces an ISO date
An SQL column if the method is to be used to calculate date offsets based on table values
skipped or false for today

Examples

Get date one week from now

$fld = $conn->OffsetDate(7); 
/*
 * returns "(trunc(sysdate)+7")
 */

Oracle: get date and time that is 60 hours (2.5 days) from current

$fld = $conn->OffsetDate(60/24, $conn->sysTimeStamp); 
/*
 *   returns "(sysdate+2.5)"
 */  
 
$conn->Execute("UPDATE TABLE SET dodate=$fld WHERE ID=$id");

SQL Server: Get Date -273.5 Hours in the past

$fld = $db->offsetDate(-273.5/24);
 
/*
 * Returns " SELECT FORMAT(DATEADD(hour ,-273.5,GETDATE()), 'yyyy-MM-dd')"
 */

Generating A Date From a column Value. In this example we would use the statement to return a date 7 days forward from the current value of the column “delivery date”.

$newDeliveryDate = $db->offsetDate(7, 'delivery_date');
 
$SQL = "SELECT $newDeliveryDate 
          FROM delivery_master";