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jvx:reference [2020/06/10 13:12] cduncan [Notes on the launcher] |
jvx:reference [2020/06/10 13:18] cduncan [DataType] |
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===== What is it? ===== | ===== What is it? ===== | ||
- | DataBooks are an active model, which allow you to directly query and manipulate the data. Contrary to many other systems [[https://sourceforge.net/projects/jvx/|JVx]] does not map the data into objects, but instead allows you to directly access it in a table like fashion, exposing columns, rows and values. | + | DataBooks are an active model, which allow you to directly query and manipulate the data. Contrary to many other systems, [[https://sourceforge.net/projects/jvx/|JVx]] does not map the data into objects, but allows you to directly access it in a table-like fashion exposing columns, rows, and values. |
- | One could say that it is like a three dimensional array, with these dimensions: | + | One could say that it is like a three dimensional array with these dimensions: |
* DataPages | * DataPages | ||
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* Columns/Values | * Columns/Values | ||
- | With DataPages containing DataRows, which itself contain the values and everything is referencing the RowDefinition, which outlines how a row looks like. | + | with DataPages containing DataRows, which in turn contain the values and everything referencing the RowDefinition, which further outlines how a row looks like. |
{{:jvx:reference:databook.png?nolink|DataBook Architecture, the DataBook contains DataPages, which contain DataRows.}} | {{:jvx:reference:databook.png?nolink|DataBook Architecture, the DataBook contains DataPages, which contain DataRows.}} | ||
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dataBook.setRowDefinition(rowDefinition); | dataBook.setRowDefinition(rowDefinition); | ||
</code> | </code> | ||
- | ==== ColumnDefinition ==== | + | ==== Column Definition ==== |
- | The ColumnDefinition defines and provides all necessary information about the column, like its DataType, its size and if it is nullable or not. You can think of it as one column in a table. | + | The column definition defines and provides all necessary information about the column, like its datatype, its size, and whether it is nullable or not. You can think of it as one column in a table. |
<code java> | <code java> | ||
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columnDefinition.setNullable(false); | columnDefinition.setNullable(false); | ||
</code> | </code> | ||
- | ==== MetaData ==== | + | ==== Metadata ==== |
- | Most of the ColumnDefinition is additional information about the column, like if it is nullable, the label of the column, default values, allowed values and similar information. | + | Most of the column definition is additional information about the column, like if it is nullable, the label of the column, default values, allowed values, and similar information. |
- | ==== DataType ==== | + | ==== Datatype ==== |
- | Of course we must define what type the value in the column has, this is done by setting a DataType on the ColumnDefinition. The DataType defines what kind of values the column holds, like if it is a String, or a Number or something else. We do provide the most often used DataTypes out of the box: | + | Of course, we must define what type the value in the column has. This is done by setting a datatype on the column definition. The datatype defines what kind of values the column holds, like if it is a String, a Number, or something else. We provide the most often used datatypes out of the box: |
* BigDecimal | * BigDecimal | ||
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* Timestamp | * Timestamp | ||
- | It is possible to add new DataTypes by simply implementing ''%%IDataType%%''. | + | It is possible to add new datatypes by simply implementing ''%%IDataType%%''. |
===== DataRow ===== | ===== DataRow ===== |