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ABENOS_QUERY_FILTER_COND - OS QUERY FILTER COND

CPI1466 during Backup   CL_GUI_FRONTEND_SERVICES - Frontend Services  
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- Query Conditions

A query condition is a logical expression that compares the attributes of a persistent class with free parameters or values. The syntax of a query condition is based on the syntax of the WHERE condition, where reference variables for object references are also supported. Like a WHERE condition, a query condition is made up of elementary comparisons that can be combined using the Boolean operators AND, OR, and NOT, where grouping using parentheses is supported.

When a query is executed using a class agent, the query is bound exactly to its persistent class. The attributes specified in a query condition must exist in the persistent class as public persistent attributes. If not, an exception is raised. On the other hand, a query that has been created can certainly be executed consecutively by class agents of different persistent classes, as long as the specified attributes exist. 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 comparison operators below are supported in a query 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. The parameter list is a list of parameter names that can be used in the query condition. The position of the parameter in the parameter list defines the index of the parameter 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 comparison operators are defined by the corresponding language element into which the logical expression is converted.

Note

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

• The layout of a query condition in a program is one of the dynamic programming techniques.

• To avoid SQL injections, the use of parameters from the parameter list of a concatenation is recommended, where dynamic values are represented as literals.

• See also SQL Injections Using Object Services.

Comparison 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, the parameter par must 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 . Explicit parentheses are possible. If no parentheses are specified, the 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' ) )

CL_GUI_FRONTEND_SERVICES - Frontend Services   TXBHW - Original Tax Base Amount in Local Currency  
This documentation is copyright by SAP AG.

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