- When to use <Source>.BuildKeyValue?
- Generic search
- Building a composite key used in a filter with bounds
- Building a composite key without using <Source>.BuildKeyValue
<Source>.BuildKeyValue (Function) In french: <Source>.ConstruitValClé
 Not available with this kind of connection
Builds the value of a composite key to implement a filter ( <Source>.Filter) or to perform a search ( <Source>.ReadSeekFirst, <Source>.ReadSeekLast, etc.). This function can be replaced by an array of values, easier to use. For example:
FileName.ReadSeekFirst(LINKEDCOMPKEY, ["Last name", "First name"])
Are equal to:
FileName.ReadSeekFirst(LINKEDCOMPKEY, ...
FileName.BuildKeyValue(LINKEDCOMPKEY, "Last name", "First name"))
Tip: To browse a data file according to a composite key, use the FOR EACH statement on composite key (syntax 5). Reminder: The composite keys are binary strings whose content cannot be displayed directly.  Versions 15 and later New in version 15Versions 17 and later New in version 17 Versions 18 and later New in version 18 Versions 21 and later New in version 21 Remark: From version 19, HFSQL is the new name of HyperFileSQL.
bufSoughtVal is Buffer
// Build the composite key
bufSoughtVal = Customer.BuildKeyValue(LastName_FirstName, "MOORE", "Vince")
// Build a String/Integer composite key
bufSoughtVal = Customer.BuildKeyValue(LASTNAME_CUSTNUM,"MOORE",12128)
// Build an Integer/Integer composite key
bufSoughtVal = Order.BuildKeyValue(ORDERID_ORDERID, 12119,593)
Syntax
<Result> = <Source>.BuildKeyValue(<Composite key> , <Value of components>)
<Result>: Buffer Value of the composite key. <Source>: Type corresponding to the specified source Name of HFSQL data file used. <Composite key>: Character string (with or without quotes) Name of the item corresponding to the composite key <Value of components>: Character string Value that will be assigned to each component of the composite key. This parameter has the following format:
<Component 1>, <Component 2>, ..., <Component N>
For example: "MOORE", "Vince". Remarks When to use <Source>.BuildKeyValue? <Source>.BuildKeyValue must be used to perform searches on the linked keys (binary string) to composite keys. Some examples: - FileA file:
COMPKEY is a composite key of FileA. Composition: FileA.LastName+FileA.FirstName - FileB file:
LINKEDCOMPKEY is a binary string key linked to FileA.COMPKEY
Performing a search on the value of the composite key:
FileB.ReadSeekFirst(LINKEDCOMPKEY, FileA.BuildKeyValue(COMPKEY, ...
"Last name", "First name"))
or
bufKey is Buffer
bufKey = FileA.BuildKeyValue(COMPKEY, "Last name", "First name")
FileB.ReadSeekFirst(LINKEDCOMPKEY, buKey)
or
FileB.ReadSeekFirst(LINKEDCOMPKEY, FileA.COMPKEY)
if FILEA is positioned on the record that must be found in FILEB. An array of values can be used instead of <Source>.BuildKeyValue:
FileB.ReadSeekFirst(LINKEDCOMPKEY, ["Last name", "First name"])
Generic search When a generic search is performed, there is no need to define the values of all the components. Only the first n values are required (n being included between 1 and the number of key components, including bounds). Building a composite key used in a filter with bounds To build the value of a composite key, use <Source>.BuildKeyValue. - If the lower bound and the upper bound of the filter must be identical, the hMinVal and hMaxVal constants must be used to fill the bounds.
The following example is used to find all the records of Customer file corresponding to "Vince Moore":
Customer.Filter(...
Customer.BuildKeyValue(LastNameFirstName, "Moore", "Vince") + hMinVal, ...
Customer.BuildKeyValue(LastNameFirstName, "Moore", "Vince") + hMaxVal)
- If the lower bound and the upper bound must be identical and if some key components are not specified, the hMinVal and hMaxVal constants must be used to fill the bounds.
The following example is used to find all the records of Customer file corresponding to "Moore":
Customer.Filter(LastNameFirstName, ...
Customer.BuildKeyValue(LastNameFirstName, "Moore" + hMinVal), ...
Customer.BuildKeyValue(LastNameFirstName, "Moore"+ hMaxVal)
Remarks: - hMinVal is equivalent to Charact(0)
- hMaxVal is equivalent to Charact(255)
Building a composite key without using <Source>.BuildKeyValue To build the value of a composite key without using <Source>.BuildKeyValue, you can: - Solution 1: Using an array of values (recommended solution):
For example:
FileB.ReadSeekFirst(LINKEDCOMPKEY, ["Last name", "First name"])
- Solution 2: Managing each type of component:
- entirely fill the text components with the hMinVal constant.
- convert the numeric components with HConvert.
For example:
MyCompositeKey = Complete(Customer.CustomerLastName, ...
Dimension(Customer.LastName), hMinVal) + ...
Complete(Customer.FirstName, Dimension(Customer.FirstName), hMinVal)
Remark: It is recommended to use <Source>.BuildKeyValue. The hMinVal constant is equivalent to Charact(0).
This page is also available for…
|
|
|