There are two types of variables, implicit and explicit variables.
Explicit variables
Explicit variables are declared with a given data type and possibly initialized with a default value, or NULL if no default value has been specified.
The code below has 3 explicit variables: 1 input parameter, 1 output parameter and 1 declared local variable.
execute udsblock(vc1 varchar(10))
returns(o1 integer)
as
declare variable b integer = 0;
begin
o1 = iif(vc1 <> '', 2, 1);
/*o1 = iif('' <> '', 2, 1); */
end
The following data types are available for variables and parameters:
char(n) |
Character string with a fixed length of n characters, padded by spaces if assigned a shorter value. |
varchar(n) |
Character string with a maximum length of n characters. |
smallint |
16 bit integer number, ranged -32768..32767 |
integer / int |
32 bit integer number, ranged -2147483648..2147483647 |
bigint |
64 bit integer number, ranged -2^63 through 2^63-1 |
float |
Floating point number with approximately 7 digits after the decimal point |
double precision |
Floating point number with approximately 15 digits after the decimal point |
numeric / decimal |
Fixed point number |
date |
Date, without time |
time |
Time, without date |
datetime / timestamp |
Date & time combined |
blob |
Large binary string without logical maximum length |
clob |
Large character string without logical maximum length |
Take note that the date/time values are implemented as floating point values internally.
Implicit variables
When you don't declare a variable, but you use them anyway, this is called an implicit variable. These have no specific data type assigned, so displaying the value might be tricky, especially with date/time values.
execute UDSBlock
as
declare DValue2 date; /* strong typed */
declare DTValue2 timestamp; /* strong typed */
declare TValue2 time; /* strong typed */
begin
/* uses an implicitly created variable */
DValue = Util.Date();
/* uses a strong typed declared variable */
DValue2 = Util.Date();
DTValue = Util.Now();
DTValue2 = Util.Now();
TValue = Util.Time();
TValue2 = Util.Time();
end
In this block, DValue is an implicit variable and has no type, while DValue2 is explicitly declared and strong typed. This means that DValue2 will always behave like a date data type, while DValue is set to a floating point without a data type specification so it's unknown that it represents a date.
Strong typed explicit variables and untyped implicit variables with the same values