Characteristics of Transactions

The structure of a transaction is comparable to the structure of a procedure or function of a high-level programming language. Transactions have the following characteristics:
  • Nested block structure is possible
  • Variables of the native types number, float, boolean and string and arrays of simple types (array of number, array of float, array of boolean, array of string) can be used
  • Variables of a transaction have local scope (can only be used inside the transaction) but global life span
  • Transactions cannot call other transactions or themselves
  • Random variables or constants can be used as input parameters of transactions
  • A transaction has no output parameters
  • Full hierarchy of expressions applies with the usual rules of precedence
  • You can use if, while, for and loop statements for flow control
  • SQL commands/FORM commands are not declared in the transactions directly but in their own section (SQL section/FORM section) and are used like variables of special data types
  • Wait statements can be used for specifying user times
  • Random variables can be used for generating random values