A function calculates a value or returns a table (table function). Functions can be called from within expressions. When an operand is evaluated with a function call, the function is first performed and then the function call replaced by the resulting value or the table which is returned. SESAM/SQL functions fall into two groups:
Time functions
String functions
Numeric functions
Aggregate functions
Table functions
Cryptographic functions
User Defined Functions (UDFs)
function ::=
{
time_function |
string_function |
numeric_function |
aggregate_function |
table_function |
crypto_function |
user_defined_function
}
time_function
Time function (see section "Time functions").
string_function
String function (see section "String functions").
numeric_function
Numeric function (see section "Numeric functions").
aggregate_function
Aggregate function (see section "Aggregate functions").
table_function
Table function (see section "Table functions").
crypto_function
Cryptographic function (see section "Cryptographic functions").
user_defined_function
User Defined Function (see section "User Defined Functions (UDFs)").