Preparing to Write Equations

Assigns a value to a global or local variable in an equation.

Calls a subequation or an external routine or an SQL statement. When you CALL something, control returns to the statement after the CALL when the called item finishes. For a subequation, control might not return if that subequation issues a HALT statement. Calls to subequations pass parameters through local and global variables and pass values back through global variables. An equation can call itself. Calls to external routines pass parameters back and forth using global variables. Calls to SQL pass parameters back and forth as well and can be used to get an array of data or update relational tables.

Can be used with the keywords INSERT, UPDATE; or DELETE, INSERT, UPDATE and DELETE. Use a WHERE clause to select a rowset. If the CHOOSE returns a global variable with the same name or the global variable A-SELECT with a value of TRUE, then that row will remain in the rowset. That is, the CHOOSE equation can be used to further limit the rows deleted.

Tests for the existence of a local variable, a global variable, or a table. It returns numeric zero for false and numeric 1 for true. It yields false for a local or global variable that has not been assigned or a table with zero rows selected from a find.

Finds the first row in the specified table using the specified key values with relational operators (Equal or Greater-or-Equal) comparing these to either local or global variables. FIND NEXT does not have any key value parameters, but it finds the next row relating to the previously issued FIND FIRST. If a FIND is successful, then references to the table and fields for that FIND are valid and return the corresponding field values.

Points to the next occurrence of the row of fields in a FIND table You can set up the equation so that failure to find an occurrence can be handled, for example, by the equation returning to the calling equation or program.

Indicates a conditional statement that must be followed by a THEN keyword and can contain an ELSE or an ELSE IF keyword. It must be terminated by the keyword END IF. It compares one operand against another operand.

Causes the equation to repeat the statements between the LOOP and the END LOOP statement in a loop until an EXIT LOOP statement is encountered within that loop, usually within an IF statement.

Writes a message to the log.

Used to make a progam more readable. It enables you to break up the program statements, and it can simplify your IF logic.

Writes debugging statements to the log and is used for problem resolution.

Table or view name.

Valid values for a field.

This operand applies only to the CALL statement.

User-defined global variable.

User-defined local variable.

(+, —, *, /) Add, Minus or Subtract, Multiply, Divide

Arithmetic operators apply to two expressions and provide an arithmetic result. You can use parentheses to group expressions or to make the equation more readable.

(AND, OR, NOT) These are logical operators. You use them within an IF statement. AND is used between two conditions. It indicates that both statements must be met for the selection to be made. For example, A and B must be true for a selection.

OR is used between two conditions. It indicates that only one of the statements must be met for selection to be made. For example, A OR B can be true for a selection.

NOT is used in conjunction with a condition to show that the condition does not exist. For example, NOT <condition>.

(=, <, <=, >, >=, < >) Equal, Less than, Less than or equal, Greater than, Greater than or equal, Less than or Greater than (for example, not equal). Relational operators compare two expressions and provide a truth value. You can use parentheses to group expressions or to enhance readability.