SqlDataFrame in Expression Language: Difference between revisions

From QPR ProcessAnalyzer Wiki
Jump to navigation Jump to search
No edit summary
No edit summary
Line 11: Line 11:
! '''Parameters'''
! '''Parameters'''
! '''Description'''
! '''Description'''
|-
||
||
Executes the SQL query for the SqlDataFrame in the datasource and returns results as in-memory DataFrame.
Examples:
<pre>
DataTableById(123).SqlDataFrame.Head(100).Collect().tocsv()
Returns the the top 100 rows from datatable id 123.
</pre>
|-
|-
||ExcludeValues (SqlDataFrame)
||ExcludeValues (SqlDataFrame)

Revision as of 10:49, 5 May 2021

SqlDataFrame represents tabular data similar to a result of an SQL query. Data in the SqlDataFrames are processed in the original datasource where the data is located (not in the QPR ProcessAnalyzer server in-memory). For each SqlDataFrame, there is an SQL query that processes and generates the actual data in the datasource.

Running SqlDataFrames and operations between them don't yet execute the SQL in the original datasource. This happens when the Collect function is called for an SqlDataFrame, which executes the SQL query of the SqlDataFrames and loads the data into QPR ProcessAnalyzer server in-memory dataframe (where it can be presented in a dashboard).

Each SqlDataFrames knows the datasource where the SQL query is executed.

There is a similar API for the SqlDataFrames as there is for the DataFrames.

SqlDataFrame functions Parameters Description

Executes the SQL query for the SqlDataFrame in the datasource and returns results as in-memory DataFrame.

Examples:

DataTableById(123).SqlDataFrame.Head(100).Collect().tocsv()
Returns the the top 100 rows from datatable id 123.
ExcludeValues (SqlDataFrame)
  1. Column name (string)
  2. Value (single item) or values (array) to exclude

Same functionality as in the DataFrame.

Head (SqlDataFrame) Number of top rows

Same functionality as in the DataFrame.

IncludeOnlyValues (SqlDataFrame)
  1. Column name (string)
  2. Value (single item) or values (array) to include

Same functionality as in the DataFrame.

Select (SqlDataFrame)

Column names (string array, or key-value pairs)

Same functionality as in the DataFrame.