SAP OS QUERY FILTER COND documentation, setup help and usage info

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Filter Conditions
A filter condition is a logical expression that compares the attributes of a persistent class with free parameters or values. The syntax of a filter condition is based on the syntax of the Open SQL WHERE
condition, whereby reference variables for object references are also supported. Like a WHERE condition, a filter condition is made up of elementary comparisons that can be joined using the boolean operators AND , OR , and NOT , where grouping using parentheses is supported.
When a query is executed using a class actor, the query is bound precisely to its persistent class. The attributes specified in a filter condition must be available in the persistent class as public persistent attributes, otherwise an exception occurs. On the other hand, a query that has been created can certainly be executed in succession by class actors of different persistent classes, as long as the specified attributes are available. When a query is executed, a SELECT statement is created internally with a WHERE condition, in which the attributes are replaced by concrete column identifiers and the free parameters are replaced by current values.
The elementary relational operators below are supported in a filter condition. An attribute, attr , of a persistent class must be specified as the first operand of a condition. The second operand
operand or pattern of a comparison may be an attribute, a parameter par , or a literal value.
The names of parameters can be defined freely by specifying a parameter list, which is a list of parameter names that can be used in the filter condition. The parameter�s position in the parameter list defines the parameter�s index in the parameter table. If no parameter list is specified, a predefined parameter list with the three parameter names PAR1 , PAR2 , and PAR3 is used.
Literal values are generally enclosed by quotation marks. The semantics of the relational operators are defined by the corresponding Open SQL language element into which the logical expression is converted.

Note
The filter condition and its parameter list are analyzed when a query is executed and transformed into an internal display. To avoid parsing each time the query is executed, the methods of the interface
IF_OS_QUERY_EXPR_FACTORY can be used to create multiple-use filter conditions in the internal representation.

Security notes

Specifying a subroutine dynamically is one of the dynamic programming techniques.

To avoid SQL injections , we recommend the use of parameters from the parameter list of a chaining, where dyanmic values are represented as literals.

See also SQL Injections Using Object Services .

Relational Operators
attr =| | | | =| = { operand }

LIKE
attr [NOT] LIKE { pattern } [ESCAPE escape]

IS NULL
attr IS [NOT] NULL

EQUALSREF
attr EQUALSREF par
Comparison of two object references. When the query is executed, parameter par has to be bound to a reference variable that refers to a persistent instance of a persistent class.

AND , OR , NOT
NOT expr
expr AND expr
expr OR expr
The semantics of the boolean operators AND , OR , and
NOT are also defined by their semantics in Open SQL . Explicit parentheses are possible. If no parentheses are specified, the Open SQL priority rules apply.

Examples
price '100' AND currency = 'EUR'
name LIKE PAR1 AND age '45' AND age '65'
( department EQUALSREF DEP1 OR department EQUALSREF DEP2 ) AND NOT
( salary '50000' AND currency = 'EUR' ) )

SAP OS QUERY FILTER COND documentation, setup help and example usage