SQL Tag Templates contain scripts for different types of data requests. Each script must return a specific type of data set, depending on the nature of the request. This section will cover the different types of scripts and their purposes, the requirements for each script and some examples, as well as using tokens in scripts for dynamic text-to-value substitution.
There are three basic script types: tag queries that are used by PARCview to get tag information, read data queries that return tag values for a given time frame, and write data queries that modify tag values in their source.
Required script** Recommended script*
Tag Scripts
|
Tag List** |
Returns list of tags used by the template |
|
Tag Info** |
Returns tag information |
|
Limit |
Returns tag limits |
|
Max |
Returns plot max for specified tag (legacy, use Tag Info instead) |
|
Min |
Returns plot min for specified tag (legacy, use Tag Info instead) |
Read Data Scripts
|
Current* |
Returns current value |
|
Data** |
Returns raw data for specified time period |
|
Data Prior* |
Returns value just prior to start time for use as start bound point |
|
Data After |
Returns value just after end time for use as end bound point |
|
Projection |
Returns projected (future) data |
|
Data Plot |
Returns plot-reduced data set for trends |
|
Data Aggregate |
Returns aggregated data |
Write Data Scripts
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Insert |
Writes single time-based value for specified tag |
|
Update |
Updates record at given time for specified tag |
|
Delete |
Deletes single record at given time for specified tag |
|
Delete Range |
Deletes all records over given interval for specified tag |
Other Scripts
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Detail |
Future use. Not currently supported for SQL.NET sources. |