Differences
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ardiextra:row-based [2019/06/06 12:42] optrix created |
ardiextra:row-based [2019/06/06 12:49] (current) optrix |
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| ^Timestamp^TMP1^TMP2^ | ^Timestamp^TMP1^TMP2^ | ||
| - | |12:42|Temperature 1|25.4|13.2| | + | |12:42|25.4|13.2| |
| - | |12.33|Temperature 1|24.4|11.5| | + | |12.33|24.4|11.5| |
| In this case, the ARDI lookup is the name of the channel. IE. "TMP1" or "TMP2". | In this case, the ARDI lookup is the name of the channel. IE. "TMP1" or "TMP2". | ||
| + | ===Keyed Column-Based Drivers=== | ||
| + | |||
| + | Some select drivers (for instance, our Oracle driver) can support a //key// on a column-based driver. In fact, they may even support **multiple** keys. | ||
| + | |||
| + | These work like a hybrid between the two - they are given two lookup values for each data-binding - the //lookup// and the //column//. | ||
| + | |||
| + | As an example, take the following... | ||
| + | |||
| + | ^Timestamp^VEHICLE^ENGINETMP^OILTMP^ | ||
| + | |12:42|1|25.4|13.2| | ||
| + | |12:42|2|25.4|13.2| | ||
| + | |12.33|1|24.4|11.5| | ||
| + | |12:33|2|25.4|13.2| | ||
| + | |||
| + | In this case, the lookup for engine temperature on vehicle 1 would be.... | ||
| + | |||
| + | |Lookup|1| | ||
| + | |Column|ENGINETMP| | ||
| + | |||
| + | //History lookups on these drivers can be quite expensive// | ||
| + | |||
| + | ===Multi-Keyed Column-Based Drivers=== | ||
| + | |||
| + | These are the same as keyed column based drivers, but with the addition of multiple keys. | ||
| + | |||
| + | As an example, take the following... | ||
| + | |||
| + | ^Timestamp^VEHICLE^OWNER^ENGINETMP^OILTMP^ | ||
| + | |12:42|1|1|25.4|13.2| | ||
| + | |12:42|2|1|25.4|13.2| | ||
| + | |12.33|1|1|24.4|11.5| | ||
| + | |12:33|2|2|25.4|13.2| | ||
| + | |||
| + | In this case, the lookup for engine temperature on vehicle 2 with owner 1 would be... | ||
| + | |||
| + | |Lookup|2,1| | ||
| + | |Column|ENGINETMP| | ||
| + | |||
| + | This would fetch the //second// record as the active, live data. | ||
| + | |||
| + | //History lookups on these drivers can be **extremely** expensive// | ||