ABAP_OS - Components of the Query Service A query is represented by a query object, which is managed by a query manager (also an object). The query manager represents the query service with respect to the ABAP program. To create a query manager, the static method GET_QUERY_MANAGER of the general system service class CL_OS_SYSTEM is required. An ABAP program does not work with the query manager and queries using class reference variables. Instead, it uses the interfaces IF_OS_QUERY_MANAGER, IF_OS_QUERY, and IF_OS_QUERY_EXPR_FACTORY to access them. A query is not executed directly, but using the method GET_PERSISTENT_BY_QUERY of the interface IF_OS_CA_PERSISTENCY of a class agent. This searches for persistent objects of the associated persistent class that match the query condition. The options for executing a query are controlled using the interface IF_OS_QUERY_OPTIONS. To do this, a structure of the type IF_OS_QUERY_OPTIONS=>OPTIONS can be passed to the method GET_PERSISTENT_BY_QUERY.
Relevant Method of the System Service Most of the components of the system service class CL_OS_SYSTEM are used internally by the Object Services. A method must be used in an application program to be able to work explicitly with object-oriented queries.
GET_QUERY_MANAGER This static method returns the return value RESULT of type IF_OS_QUERY_MANAGER containing a reference to the Query Manager. The query manager is created when the Object Services are initialized.
Methods of the Query Manager The query manager manages the object-oriented queries of the ABAP program and is executed from interface IF_OS_QUERY_MANAGER.
IF_OS_QUERY_MANAGER~CREATE_QUERY Creates a query and returns a reference to the query object in the return value RESULT of type IF_OS_QUERY. The query condition is passed to the parameter I_FILTER of type string. The sort condition is passed to the parameter I_ORDERING of type string. If the parameters of the query are specified using a parameter list, they must be passed to the parameter I_PARAMETERS of type string.
Methods of a Query Queries are executed from interfaces IF_OS_QUERY and IF_OS_QUERY_EXPR_FACTORY.
Methods of the Interface IF_OS_QUERY
IF_OS_QUERY~GET_EXPR_FACTORY Returns a reference to a query expression factory in the return parameter RESULT of type IF_OS_QUERY_EXPR_FACTORY. Technically speaking, a query expression factory is part of a query object, although it is executed using the interface IF_OS_QUERY_EXPR_FACTORY, like a separate object.
IF_OS_QUERY~SET_FILTER_EXPR Sets the query condition. The internal representation of the query condition that is created with a query expression factory is passed to the parameter I_FILTER_EXPR of type IF_OS_QUERY_FILTER_EXPR.
IF_OS_QUERY~SET_PARAMETERS_EXPR Sets the parameter list of the query condition. The internal representation of the parameter list that is created with a query expression factory is passed to the parameter I_PARAMETERS_EXPR of type IF_OS_QUERY_PARAMETERS_EXPR.
IF_OS_QUERY~SET_ORDERING_EXPR Sets the sort condition. The internal representation of a sort condition created with the query expression factory is passed to the parameter I_ORDERING_EXPR of type IF_OS_QUERY_ORDERING_EXPR.
IF_OS_QUERY~PARSE Creates the internal representation of the query condition, the parameter list, and the sort condition if these have not yet been created or set.
Methods of the Interface IF_OS_QUERY_EXPR_FACTORY
IF_OS_QUERY_EXPR_FACTORY~CREATE_OPERATOR_EXPR Creates either a query condition of the form attr1 operator attr2, where attr1, operator, and attr2 are the values of the parameters I_ATTR, I_OPERATOR, and I_ATTR2 or a query condition of the form attr1 operator 'val' or attr1 operator val_w_quotes where val and val_w_quotes are the values of the parameters I_VAL and I_VAL_W_QUOTES. If the parameter I_IDX of type i is passed, val is the value of the parameter from the parameter list, for which the index when the query is executed is determined by the value of the parameter I_IDX. The query condition that is created is returned in the return value RESULT of type IF_OS_QUERY_FILTER_EXPR.
IF_OS_QUERY_EXPR_FACTORY~CREATE_LIKE_EXPR Depending on the value of the parameter I_NOT, creates a query condition of the form attr $[NOT$] LIKE 'pattern' or attr $[NOT$] LIKE pattern_w_quotes, where attr, pattern, and pattern_w_quotes are the values of the parameters I_ATTR, I_PATTERN and I_PATTERN_W_QUOTES. If the parameter I_IDX of type i is passed, pattern is the value of the parameter from the parameter list, for which the index when the query is executed is determined by the value of the parameter I_IDX. Passing one of the parameters I_ESCAPE or I_ESCAPE_W_QUOTES appends the definition of an escape character of the form ... ESCAPE 'escape' or ... ESCAPE escape_w_quotes where escape and escape_w_quotes are the values of the parameters I_ESCAPE and I_ESCAPE_W_QUOTES. The query condition that is created is returned in the return value RESULT of type IF_OS_QUERY_FILTER_EXPR.
IF_OS_QUERY_EXPR_FACTORY~CREATE_ISNULL_EXPR Depending on the value of the parameter I_NOT, creates a query condition of the form attr IS $[NOT$] NULL, where attr is the value of the parameter I_ATTR. The query condition that is created is returned in the return value RESULT of type IF_OS_QUERY_FILTER_EXPR.
IF_OS_QUERY_EXPR_FACTORY~CREATE_REF_EXPR Creates a query condition of the form attr EQUALSREF ref, where attr is the value of the parameter I_ATTR and ref is the value of the parameter from the parameter list whose index when the query is executed is determined by the value of the parameter I_IDX. Instead of using a parameter to set the persistent object reference, the instance GUID and class GUID can be specified using the parameters I_GUID and I_CLSGUID of type OS_GUID. The query condition that is created is returned in the return value RESULT of type IF_OS_QUERY_FILTER_EXPR.
IF_OS_QUERY_EXPR_FACTORY~CREATE_NOT_EXPR Creates a query condition of the form NOT ( expr ), where expr is a query condition that already exists and was passed to the parameter I_EXPR. The new query condition is returned in the return value RESULT.
IF_OS_QUERY_EXPR_FACTORY~CREATE_AND_EXPR Creates a query condition of the form ( expr1 ) AND ( expr2 ) where expr1 or expr2 are query conditions that already exist and were passed to the parameters I_EXPR1 or I_EXPR2 . The new query condition is returned in the return value RESULT.
IF_OS_QUERY_EXPR_FACTORY~CREATE_OR_EXPR Creates a query condition of the form ( expr1 ) OR ( expr2 ) where expr1 or expr2 are query conditions that already exist and were passed to the parameters I_EXPR1 or I_EXPR2 . The new query condition is returned in the return value RESULT.
IF_OS_QUERY_EXPR_FACTORY~CREATE_PARAMETERS_EXPR Creates a parameter list. The parameter list that is created is returned in return value RESULT of type IF_OS_QUERY_PARAMETERS_EXPR . The parameters are appended consecutively when the method APPEND of an additional interface IF_OS_QUERY_PARAMETERS_EXPR is called. The parameter name is passed to the parameter I_PAR.
IF_OS_QUERY_EXPR_FACTORY~CREATE_ORDERING_EXPR Creates a sort condition. The sort condition is returned in the return value RESULT of type IF_OS_QUERY_ORDERING_EXPR. The attributes used for the sort are appended consecutively when the method APPEND_ASCENDING or APPEND_DESCENDING of the additional interface IF_OS_QUERY_ORDERING_EXPR is called. The parameter name is passed to the parameter I_ATTR.
