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- Properties specific to hbScanParameter variables
- Iterating over data with the filter
- Examples of filters
hbScanParameter (Variable type)
The hbScanParameter type is used to define the parameters for iterating over the records in an HBase database. You can define and change the characteristics of these iteration parameters using different WLanguage properties. Note: For more details on the declaration of this type of variable and the use of WLanguage properties, see Declaring a variable.
Connexion is hbConnection
Connexion.Server = "MonServeur"
MonScan is hbScanParameter
MonScan.Connection = connection
MonScan.Table = "blog"
MonScan.Filter = "{ ""type"": ""ColumnPrefixFilter"", ""value"": """ + ...
Encode("Titre", encodeBASE64) + """ }"
FOR EACH MonRésultat OF MonScan
Trace("La colonne " + MonRésultat.Colonne.Famille + ":" + ...
MonRésultat.Colonne.Qualificatif + ...
" de la ligne " + MonRésultat.Ligne + " vaut " + MonRésultat.Valeur)
END
Propiedades Properties specific to hbScanParameter variables The following properties can be used to handle the description of iteration parameters: | | | | Property name | Type used | Effect |
|---|
| Column | Array of hbColumn | Families or columns (items) found in the result of the iteration. | | Connection | hbConnection variable | Connection to the HBase server to be used for the iteration. | | EndRow | Buffer | Identifier of the last row (record) of the iteration. This row will not be included in the iteration. | | EndTimestamp | DateTime | End date and time for selecting rows. The iteration will only return the rows containing cells up to this date and time. | | Filter | Character string | Filter that will be applied during the iteration. This filter is in JSON format. The literal values must be encoded in Base64, by using Encode for example. For more details, see the HBase documentation. | | MaxVersion | Integer | Maximum number of versions returned for each cell (value of item). Indeed, a history of values is stored in the HBase database for each cell. | | StartRow | Buffer | Identifier of the first row (record) of the iteration. This row will be included in the iteration. | | StartTimestamp | DateTime | Start date and time for selecting rows. The iteration will only return the rows containing cells from this date and time. | | Table | Character string | Name of the HBase table to iterate over. |
Observaciones Iterating over data with the filter To iterate over data with a filter: - Define the Filter property of the variable.
- Use the FOR EACH syntax to initialize the iteration with the filter. The following syntax must be used:
POUR TOUT <Résultat> SUR <Variable de paramétrage de scan>
Examples of filters - Filter on column value: MyFamily:MyQualifier = 'Value'.
MonScan.Filter = ...
"{" + ...
"""type"": ""SingleColumnValueFilter""," + ...
"""op"": ""EQUAL""," + ...
"""family"": """ + Encode("MaFamille", encodeBASE64) + """," + ...
"""qualifier"": """ + Encode("MonQualificatif", encodeBASE64) + """," + ...
"""latestVersion"": true," + ...
"""comparator"": {" + ...
"""type"": ""BinaryComparator""," + ...
"""value"": """ + Encode("Valeur", encodeBASE64) + """}" + ...
"}"
- Filter the columns whose name starts with "Title":
MonScan.Filter = ...
"{" + ...
"""type"": ""ColumnPrefixFilter""," + ...
"""value"": """ + Encode("Titre", encodeBASE64) + """," + ...
"}"
- Filter the data according to several filters:
MonScan.Filter = ...
"{" + ...
"""type"": ""FilterList""," + ...
"""op"": ""MUST_PASS_ALL""," + ...
"""filters"": [" + ...
"{" + ...
filtre1 + ...
"}," + ...
"{" + ...
filtre2 + ...
"}" + ...
"]" + ...
"}"
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