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PQL47 (PQL Function Library - CPM 4.7)

PU_MEDIAN

Applies to: CELONIS 4.0 CELONIS 4.2 CELONIS 4.3 CELONIS 4.4 CELONIS 4.5 CELONIS 4.6 CELONIS 4.7

Description

Calculates the median of the specified column for each element of the given child table.

The median is the middle element of a group. If the group has an even number of elements, the upper value of the two middle values is taken as the median.

Like the regular MEDIAN operator, the column can either be an INT, FLOAT or DATE column. The data type of the result is the same as the input column data type.

Syntax
PU_MEDIAN ( child_table, parent_table.column [, filter_expression] )

  • child_table: The table to which the aggregation result should be pulled. This can be:

  • parent_table.column: The column which should be aggregated for every row of the child_table.

  • filter_expression (optional): An optional filter expression to specify which values of the parent_table.column should be taken into account for the aggregation.

NULL handling

If no value in the parent table exists for the element in the child table (either because all values of the parent table are filtered out, or because no corresponding value exists in the first place), NULL will be returned. NULL values in the parent table column are treated as if the row does not exist.

Examples

[1] Calculate the maximum of the case table values for each company code.

Query

Column1

"companyDetail"."companyCode"

Column2

PU_MEDIAN ( "companyDetail" , "caseTable"."value" )

Input

Output

caseTable

caseId : INT

companyCode : STRING

value : INT

1

'001'

600

2

'001'

400

3

'001'

200

4

'002'

300

5

'002'

300

6

'003'

200

companyDetail

companyCode : STRING

country : STRING

'001'

'DE'

'002'

'DE'

'003'

'US'

Foreign Keys

caseTable.companyCode

companyDetail.companyCode

Result

Column1 : STRING

Column2 : INT

'001'

400

'002'

300

'003'

200

[2] PU functions can be used in a FILTER. In this example, the company codes are filtered such that the corresponding median case table value is smaller than 300.

Query

Filter

FILTER PU_MEDIAN ( "companyDetail" , "caseTable"."value" ) < 300;

Column1

"companyDetail"."companyCode"

Input

Output

caseTable

caseId : INT

companyCode : STRING

value : INT

1

'001'

600

2

'001'

400

3

'001'

200

4

'002'

300

5

'002'

300

6

'003'

200

companyDetail

companyCode : STRING

country : STRING

'001'

'DE'

'002'

'DE'

'003'

'US'

Foreign Keys

caseTable.companyCode

companyDetail.companyCode

Result

Column1 : STRING

'003'

[3] PU functions can be used inside another aggregation function. In this example, the maximum value of all median case table values for each company code is calculated.

Query

Column1

MAX ( PU_MEDIAN ( "companyDetail" , "caseTable"."value" ) )

Input

Output

caseTable

caseId : INT

companyCode : STRING

value : INT

1

'001'

600

2

'001'

400

3

'001'

200

4

'002'

300

5

'002'

300

6

'003'

200

companyDetail

companyCode : STRING

country : STRING

'001'

'DE'

'002'

'DE'

'003'

'US'

Foreign Keys

caseTable.companyCode

companyDetail.companyCode

Result

Column1 : INT

400

[4] Calculate the median of the case table values for each company code. Only consider cases with an ID larger than 2.

Query

Column1

"companyDetail"."companyCode"

Column2

PU_MEDIAN ( "companyDetail" , "caseTable"."value" , "caseTable"."caseID" > 2 )

Input

Output

caseTable

caseId : INT

companyCode : STRING

value : INT

1

'001'

600

2

'001'

400

3

'001'

200

4

'002'

300

5

'002'

300

6

'003'

200

companyDetail

companyCode : STRING

country : STRING

'001'

'DE'

'002'

'DE'

'003'

'US'

Foreign Keys

caseTable.companyCode

companyDetail.companyCode

Result

Column1 : STRING

Column2 : INT

'001'

200

'002'

300

'003'

200

[5] Calculate the median of the case table values for each company code. Only consider cases with an ID larger than 3. All case table values for companyCode '001' are filtered out, which means that in this case, NULL is returned.

Query

Column1

"companyDetail"."companyCode"

Column2

PU_MEDIAN ( "companyDetail" , "caseTable"."value" , "caseTable"."caseID" > 3 )

Input

Output

caseTable

caseId : INT

companyCode : STRING

value : INT

1

'001'

600

2

'001'

400

3

'001'

200

4

'002'

300

5

'002'

300

6

'003'

200

companyDetail

companyCode : STRING

country : STRING

'001'

'DE'

'002'

'DE'

'003'

'US'

Foreign Keys

caseTable.companyCode

companyDetail.companyCode

Result

Column1 : STRING

Column2 : INT

'001'

null

'002'

300

'003'

200

[6] Example over three tables: For each entry in table B, calculate the median of the values that are larger than 100 in table C. Tables B and C do not have a direct connection, but are connected via table A.

Query

Column1

"B"."B_KEY"

Column2

PU_MEDIAN ( "B" , "C"."VALUE" , "C"."VALUE" > 100 )

Input

Output

A

B_KEY : INT

C_KEY : STRING

VALUE : INT

1

'A'

100

1

'B'

200

2

'C'

300

2

'D'

400

3

'E'

500

3

'F'

600

B

B_KEY : INT

1

2

C

C_KEY : STRING

VALUE : INT

'A'

400

'A'

100

'A'

200

'B'

100

'C'

200

'D'

500

Foreign Keys

C.C_KEY

A.C_KEY

B.B_KEY

A.B_KEY

Result

Column1 : INT

Column2 : INT

1

400

2

500

See also: