CLASS ndi.query¶
ndi.query - create a query object for searching the database
Creates an ndi.query object, which has a single property
SEARCH that is a structure array of search structures
appropriate for use with vlt.data.fieldsearch.
Tha is, SEARCH has the fields:
Field: | Description
---------------------------------------------------------------------------
field | A character string of the field of A to examine
operation | The operation to perform. This operation determines
| values of fields 'param1' and 'param2'.
|----------------------|
| 'regexp' - are there any regular expression matches between
| the field value and 'param1'?
| 'exact_string' - is the field value an exact string match for 'param1'?
| 'contains_string' - is the field value a char array that contains 'param1'?
| 'exact_number' - is the field value exactly 'param1' (same size and values)?
| 'lessthan' - is the field value less than 'param1' (and comparable size)
| 'lessthaneq' - is the field value less than or equal to 'param1' (and comparable size)
| 'greaterthan' - is the field value greater than 'param1' (and comparable size)
| 'greaterthaneq' - is the field value greater than or equal to 'param1' (and comparable size)
| 'hasfield' - is the field present? (no role for 'param1' or 'param2')
| 'hasanysubfield_contains_string' - Is the field value an array of structs or cell array of structs
| such that any has a field named 'param1' with a string that contains the string
| in 'param2'?
| 'or' - are any of the searchstruct elements specified in 'param1' true?
| 'isa' - is 'param1' either a superclass or the document class itself of the ndi.document?
| 'depends_on' - does the document depend on an item with name 'param1' and value 'param2'?
|----------------------|
param1 | Search parameter 1. Meaning depends on 'operation' (see above).
param2 | Search parameter 2. Meaning depends on 'operation' (see above).
---------------------------------------------------------------------------
See vlt.data.fieldsearch for full documentation of the search structure.
There are a few creator options:
NDI_QUERY_OBJ = ndi.query(SEARCHSTRUCT)
Accepts a SEARCHSTRUCT with the fields above
NDI_QUERY_OBJ = ndi.query(SEARCHCELLARRAY)
Accepts a cell array with SEARCHCELLARRAY = {'property1',value1,'property2',value2, ...}
This query is converted into a SEARCHSTRUCT with the 'regexp' operator.
NDI_QUERY_OBJ = ndi.query(FIELD, OPERATION, PARAM1, PARAM2)
creates a SEARCHSTRUCT with the fields of the appropriate names.
Superclasses¶
none
Properties¶
| Property | Description |
|---|---|
| searchstructure | search structure |
Methods¶
| Method | Description |
|---|---|
| and | add ndi.query objects |
| or | search for this ndi.query object or that ndi.query object |
| query | create a query object for searching the database |
| searchcellarray2searchstructure | convert a search cell array to a search structure |
| searchstruct | make a search structure from field, operation, param1, param2 inputs |
| string2query | create an ndi.query from a simple paramterized string |
| to_searchstructure | convert an ndi.query object to a set of search structures |
Methods help¶
and - add ndi.query objects
C = AND(A,B) or C = A & B
Combines the searches from A and B into a search C. The searchstructure field of
C will be a concatenated version of those from A and B. The query C will only pass if
all of the characteristics of A and B are satisfied.
or - search for this ndi.query object or that ndi.query object
C = OR(A,B)
Produces a new ndi.query object C that is true if either ndi.query A or ndi.query B is true.
query - create a query object for searching the database
Creates an ndi.query object, which has a single property
SEARCH that is a structure array of search structures
appropriate for use with vlt.data.fieldsearch.
Tha is, SEARCH has the fields:
Field: | Description
---------------------------------------------------------------------------
field | A character string of the field of A to examine
operation | The operation to perform. This operation determines
| values of fields 'param1' and 'param2'.
|----------------------|
| 'regexp' - are there any regular expression matches between
| the field value and 'param1'?
| 'exact_string' - is the field value an exact string match for 'param1'?
| 'contains_string' - is the field value a char array that contains 'param1'?
| 'exact_number' - is the field value exactly 'param1' (same size and values)?
| 'lessthan' - is the field value less than 'param1' (and comparable size)
| 'lessthaneq' - is the field value less than or equal to 'param1' (and comparable size)
| 'greaterthan' - is the field value greater than 'param1' (and comparable size)
| 'greaterthaneq' - is the field value greater than or equal to 'param1' (and comparable size)
| 'hasfield' - is the field present? (no role for 'param1' or 'param2')
| 'hasanysubfield_contains_string' - Is the field value an array of structs or cell array of structs
| such that any has a field named 'param1' with a string that contains the string
| in 'param2'?
| 'or' - are any of the searchstruct elements specified in 'param1' true?
| 'isa' - is 'param1' either a superclass or the document class itself of the ndi.document?
| 'depends_on' - does the document depend on an item with name 'param1' and value 'param2'?
|----------------------|
param1 | Search parameter 1. Meaning depends on 'operation' (see above).
param2 | Search parameter 2. Meaning depends on 'operation' (see above).
---------------------------------------------------------------------------
See vlt.data.fieldsearch for full documentation of the search structure.
There are a few creator options:
NDI_QUERY_OBJ = ndi.query(SEARCHSTRUCT)
Accepts a SEARCHSTRUCT with the fields above
NDI_QUERY_OBJ = ndi.query(SEARCHCELLARRAY)
Accepts a cell array with SEARCHCELLARRAY = {'property1',value1,'property2',value2, ...}
This query is converted into a SEARCHSTRUCT with the 'regexp' operator.
NDI_QUERY_OBJ = ndi.query(FIELD, OPERATION, PARAM1, PARAM2)
creates a SEARCHSTRUCT with the fields of the appropriate names.
searchcellarray2searchstructure - convert a search cell array to a search structure
SEARCHSTRUCT = SEARCHCELLARRAY2SEARCHSTRUCTURE(SEACHCELLARRAY)
Converts a cell array with SEARCHCELLARRAY = {'property1',value1,'property2',value2, ...}
into a SEARCHSTRUCT with the 'regexp' operator in the case of a character 'value' or the 'exact_number'
operator in the case of a non-character value.
See also: vlt.data.fieldsearch, ndi.query/ndi.query
searchstruct - make a search structure from field, operation, param1, param2 inputs
SEARCHSTRUCT_OUT = SEARCHSTRUCT(FIELD, OPERATION, PARAM1, PARAM2)
Creates search structure with the given fields FIELD, OPERATION, PARAM1, PARAM2.
See also: vlt.data.fieldsearch, ndi.query/ndi.query
string2query - create an ndi.query from a simple paramterized string
Q_OUT = STRING2QUERY(STR)
STRING2QUERY is a short-cut for specifying simple queries using a
a single character string. It is not as powerful as using the
usual ndi.query creator but it is a useful shortener for some situations.
STR should be a string of the form
'parameter1=value1,parameter2="value2",parameterN=valueN'
Parameters values are to be surrounded in quotes if they are
character strings; otherwise, they are assumed to be numbers and
are converted to numbers using the str2num function.
If parameter is equal to 'isa', then the query uses the operator
for the ndi.query is 'isa' and the value is the document type.
Example:
q_out = ndi.query.string2query('element.name="ctx",element.ref=1')
% q_out = ndi.query('element.name','exact_string','ctx','') & ...
% ndi.query('element.ref','exact_number',1)
q_out2 = ndi.query.string2query('isa=subject')
% q_out2 = ndi.query('','isa','subject','')
to_searchstructure - convert an ndi.query object to a set of search structures
SEARCHSTRUCTURE = TO_SEARCHSTRUCTURE(NDI_QUERY_OBJ)
Converts an NDI_QUERY_OBJECT to a set of search structures without any
ndi.query dependencies (see vlt.data.fieldsearch).
See also: vlt.data.fieldsearch