SQL Expressions
SQL expressions are used in the Snowflake chart and thus they are expressions that are executed in Snowflake. Note that SQL expressions are different than the in-memory expressions. In addition to Snowflake chart, SQL expressions are used in the Where and WithColumn functions in SQLDataFrames.
It's possible to run in-memory expressions that are embedded into SQL expressions using #expr{} syntax. For examples, see the DurationBetweenDates function.
Operators
Following operators are supported by SQL expressions:
- Arithmetic operators
+ - * / %
- Comparison operators
== < <= > >= !=
- Logical operators
&& || !
Following data types are supported by SQL expressions:
- String
"this is a string"
- Integer
123
- Decimal number
123.45
- Boolean
true false
- Null value
null
- Arrays
[1, 2, 3]
- Objects
#{ "key1": "value1", "key2": 3.7, "key3": false }
To get an item from an array, use following syntax:
Column("arraydata")[2]To get a value from an object, use following syntax:
Column("objectdata")["key1"]
Expressions resulting in boolean value need to be enclosed to the CaseWhen function. For example, expression Column("MyColumn") < 5 doesn't work, but following does:
CaseWhen(Column("MyColumn") < 5, true, false)
Mathematical functions
| Function | Description |
|---|---|
| Abs | Returns absolute value of given number. Example:
Abs(-5) Returns: 5 |
| Ceiling |
Returns given value rounded to the nearest equal or larger integer. The data type should be one of the numeric data types. If the value is null, then the result is also null. |
| Floor |
Returns given value rounded to the nearest equal or smaller integer. The data type should be one of the numeric data types. If the value is null, then the result is also null. |
| Log | Returns given logarithm of given number. The first parameter is the base number and the second parameter is number to take the logarithm from. Example:
Log(10, 1000) Returns: 3 Log(2, 16) Returns: 4 |
| Mod | Returns remainder of division operation of given numbers. The first parameter is the dividend and the second parameter is the divisor. Example:
Mod(10, 4) Returns: 2 |
| Power | Returns given power of given number. First parameter is the base number and second is the exponent: Example:
Power(2, 4) Returns: 16 |
| Rand | Returns random number between 0 and 1, where 0 is included and 1 is excluded. It's possible that when getting random for multiple columns, the same row may have the same random number. Example:
Rand() Returns: 0.78452600 (for example) |
| Round |
Rounds given number to given precision. Parameters:
Examples: Round(123.456) Returns 123 Round(123.456, 2) Returns 123.46 Round(123.456, -1) Returns 120 Round(123.456, 0) Returns 123 |
| Sign | Return sign of given number, i.e., returns 1 (when number is a positive number) or 0 (when number is a negative number or zero). Example:
Sign(-2) Returns: -1 |
| Sqrt | Return square root of given number. Example:
Sqrt(9) Returns: 3 |
Date functions
| Function | Description |
|---|---|
| Year | Returns the year of given timestamp. |
| Quarter | Returns the quarter (1-4) of given timestamp. |
| Month | Returns the months part (1-12) of given timestamp. |
| Day |
Returns the days of the month (1-31) of given timestamp. Day(Column("DateColumn"))
|
| Hour | Returns the hours part (0-59) of given timestamp. |
| Minute | Returns the minutes part (0-59) of given timestamp. |
| Second | Returns the seconds part (0-59) of given timestamp. |
| Millisecond | Returns the milliseconds part (0-999) of given timestamp. |
| DayOfWeek | Returns the day of week for given timestamp as number. Monday is 1, Tuesday is 2, ... and Sunday is 7. Note that Snowflake's WEEK_OF_YEAR_POLICY and WEEK_START session parameters affect the behavior.
DayOfWeek("2023-07-10 00:00:00.000")
Returns: 1
|
| DayOfYear | Returns the day of year for given timestamp. The 1st of January is 1, the 2nd of January is 2 and so on. The value can be between 1 and 366.
DayOfYear("2023-01-01 00:00:00.000")
Returns: 1
DayOfYear("2023-12-31 00:00:00.000")
Returns: 365
|
| WeekOfYear | Returns the ISO week number for given timestamp. The value can be between 1 and 53. The 1st of January is in the week 1 if it's Monday, Tuesday, Wednesday or Thursday. If the 1st of January is Friday, Saturday or Sunday, week 1 is the next week.
WeekOfYear("2023-01-01 00:00:00.000")
Returns: 52
WeekOfYear("2023-01-02 00:00:00.000")
Returns: 1
|
| DateAdd |
Adds a duration to a date, i.e., moves the date back or forth in time. The duration is specified as integer and the unit can be chosen from variety of options. The duration can also be a negative number for moving to an earlier time. Parameters:
DateAdd("month", 1, "01/01/2022")
Returns 1st of February 2022 at midnight.
DateAdd("year", -2, "01/01/2022")
Returns 1st of January 2020 at midnight.
DateAdd("hour", 12, "01/01/2022")
Returns 1st of January 2022 at 12 o'clock.
|
| DateDiff |
Calculates how many of the specified date part boundaries there are between the specified dates. Parameters:
|
| DurationBetweenDates | Calculates duration between the specified dates and returns the duration as float. This function gives more precise result than the DateDiff function that complies with the traditional logic in the SQL language. Parameters:
Example: Calculated duration between two dates: DurationBetweenDates("hour", Column("date1"), Column("date2"))
Example: Calculated duration between two dates using model's business calendar: DurationBetweenDates("hour", Column("date1"), Column("date2"), #expr{_model.DefaultCalendar()})
|
| TruncateDate |
Truncates given date to given time unit. The truncation gives the timestamp of the beginning of the period defined by the time unit (logic thus resembles the floor function for numbers). Parameters:
Examples: TruncateDate(Column("MyDateColumn"), "year")
Returns timestamp representing beginning of a year, e.g. 2022-01-01 00:00:00.
TruncateDate(Column("MyDateColumn"), "day")
Returns timestamp representing beginning of a day, e.g. 2022-04-16 00:00:00.
|
| ToTimestamp | Converts string into corresponding date type of value. If the conversion fails, an exception is thrown. Parameters:
Examples: ToTimestamp("2023-09-15 16:31:01", "YYYY-MM-DD HH24:MI:SS")
ToTimestamp("01.12.2023 09:14:58.849 PM", "DD.MM.YYYY HH12:MI:SS.FF3 AM")
|
| TryToTimestamp |
Tries to converts string into corresponding date type of value. If the conversion fails, null is returned. Parameters:
Example: Successful date conversion: TryToTimestamp("2023-09-15 16:31:01", "YYYY-MM-DD HH24:MI:SS")
Example: Returns null because formatting doesn't match with the data: TryToTimestamp("2023-09-15", "DD.MM.YYYY")
|
| UnixMilliseconds | Returns the time as Unix compatible milliseconds (i.e., milliseconds from the first of January 1970 midnight UTC).
UnixMilliseconds("2024-06-19 21:10:00.123")
Returns: 1718831400123
|
String functions
| Function | Description |
|---|---|
| Char | Converts Unicode code into corresponding character. If an invalid code point is specified, an error is returned.
Examples: Char(65) Returns: A Concat(Char(52), Char(53)) Returns: 45 |
| CharIndex | Returns the starting position of the first occurrence of the first argument in the second argument. The first character has the starting position 1. Returns 0 if the search doesn't find any results.
Parameters:
Examples: CharIndex("c", "abcdefg")
Returns: 3
CharIndex("ef", "abcdefg")
Returns: 5
CharIndex("fe", "abcdefg")
Returns: 0
CharIndex("c", "abcdefgc", 4)
Returns: 8
|
| Concat |
Return the concatenated string value of given values. Concat("part 1", "part 2")
Returns "part 1part 2"
Concat(Column("column1"), " ", Column("column2"))
Returns column1 and column2 value concatenated separated by space.
|
| Length |
Returns length of a given string, i.e., the number of characters in a string. Examples: Length("test")
Returns: 4
Length("long text ending to space ")
Returns: 26
Length(Column("MyData"))
|
| Like |
Determines whether given string matches given pattern, and returns either true (for match) or false (for no match). Following special characters can be used in the pattern:
Parameters:
When the percentage and underscore characters need to be used as normal characters in the search pattern (not as special characters), escaping for them is needed. By default, there is no escape character available, so it needs to be defined using the 3rd parameter. Any character can be used as the escape character, but it might be a good practice to use the backslash (\). See below an example of using the escape character. The comparison is case-sensitive for Snowflake, and for SQL Server it is dependent on the server collation. The Like function can be used with Where and CaseWhen functions which accept boolean values. Examples: Like(Column("TextData"), "a%")
Returns true for all rows starting with "a".
Like(Column("TextData"), "%aa%")
Returns true for all rows containing "aa".
Like(Column("TextData"), "abc_")
Returns true for all rows starting with "abc" and having four characters.
Like(Column("TextData"), "__a")
Returns true for all rows ending to "a" and having three characters.
dataFrame.Where(Like(Column("Region"), "t%"))
Filters dataframe rows where column Region starts with "t".
Like("a%b", "%\\%%", "\\")
Searches for a percentage character.
|
| LPad |
Left-pads a base string with characters from a pad string. If the pad string is longer than one character, the pad string is repeated cyclically. If the base string is longer than the target length, it is truncated to the target length. Parameters:
Examples: LPad("abc", 5) // => " abc"
LPad("abc", 6, "*") // => "***abc"
LPad("abc", 8, "xy") // => "xyxyxabc"
LPad("abc", 3, "*") // => "abc"
LPad("abcdef", 3, "*") // => "abc"
|
| Regexp | Returns true if the subject matches the specified regular expression pattern. First parameter is the subject and second parameter is the regular expression pattern.
Examples: Regexp("abcd", "(ab).*")
Returns: true
Regexp("abcd", ".*(bd).*")
Returns: false
Regexp("1234", "\\d")
Returns: false
Regexp("1234", "\\d*")
Returns: true
Regexp("123A4", "\\d*")
Returns: false
|
| Replace | Removes all occurrences of a specified substring and replaces them with another substring. Parameters:
Example: Replace("QPR Software Oyj", " Oyj", "")
Returns: QPR Software Replace("QPR Software Oyj", "Software Oyj", "ProcessAnalyzer")
Returns: QPR ProcessAnalyzer |
| RPad |
Right-pads a base string with characters from a pad string. If the pad string is longer than one character, the pad string is repeated cyclically. If the base string is longer than the target length, it is truncated to the target length. Parameters:
Examples: RPad("abc", 5) // => "abc "
RPad("abc", 6, "*") // => "abc***"
RPad("abc", 8, "xy") // => "abcxyxyx"
RPad("abc", 3, "*") // => "abc"
RPad("abcdef", 3, "*") // => "abc"
|
| Substring |
Returns substring of given string, based on given start index and length. Function has following parameters:
Substring("123456789", 5)
Returns: 56789
Substring("123456789", 5, 3)
Returns: 567
Substring(Column("MyColumn"), 1, 4)
Returns the first 4 characters of the MyColumn data.
|
| ToLower | Return string where all the characters of the input string have been converted into lower case characters.
Examples: ToLower("Test")
Returns: test
|
| ToUpper | Return string where all the characters of the input string have been converted into upper case characters.
Example: ToUpper("Test")
Returns: TEST
|
| Trim |
Trims a string, i.e., removes spaces from the beginning and end of a string. Only characters with code 32 are removed, which is the most common space character. Example: Trim(Column("MyColumn"))
Returns column "MyColumn" where leading and trailing spaces have been removed.
Trim(" test test ")
Returns "test test".
|
| Unicode | Returns Unicode code for the first character in the string. If the string is empty, a value of 0 is returned.
Examples: Unicode("A")
Returns: 65
Unicode("45")
Returns: 52
|
Rank functions
| Function | Description |
|---|---|
| FirstValue | Returns the first value generated by an expression within an ordered group of values. Parameters:
Example: Get the case start time: FirstValue(Timestamp, [TimeStamp, EventType], [true, true], [CaseId]) |
| LastValue | Returns the last value generated by an expression within an ordered group of values. Parameters:
Example: Get the case end time: LastValue(TimeStamp, [TimeStamp, EventType], [true, true], [CaseId]) |
| NthValue | Returns the nth value generated by an expression within an ordered group of values. Parameters:
Example: Get the timestamp of the 3rd event in a case: NthValue(TimeStamp, 2, [TimeStamp, EventType], [true, true], [CaseId]) |
| Lag | Similar to the Lead function, except refers to the previous row(s) instead of the next row(s).
Example: For events list, get the MyAttribute attribute value from the two steps previous event: Lag(Column("MyAttribute"), [TimeStamp, EventType], [true, true], [CaseId], 2, "N/A"))
|
| Lead |
Returns value that is evaluated by accessing data in the next row. If a column with given columnId already exists in the DataFrame, the new column will overwrite the existing column. Parameters:
Example: For events list, get the next event timestamp: Lead(TimeStamp, [TimeStamp, EventType], [true, true], [CaseId])) |
| RowNumber | Returns a unique row number for each row within an ordered group of values. The row number starts at 1 and continues up sequentially. Parameters:
Example: Returns the row number of the row when the rows are sorted in an ascending order based on the Revenue column: RowNumber([Column("Revenue")])
Same as the previous, except that the row numbers are also partitioned by CaseId column: RowNumber([Column("Revenue")], null, [Column("CaseId")])
|
| Rank | Returns the rank of a value within an ordered group of values. The rank value starts at 1 and continues up sequentially. If two values are the same, they have the same rank. Parameters:
Example: Returns the rank of the row when the rows are sorted in an ascending order based on the value of Revenue column: Rank([Column("Revenue")])
Same as the previous, except that the ranks are also partitioned by CaseId column. Rank([Column("Revenue")], null, [Column("CaseId")])
|
| DenseRank | Returns the rank of a value within a group of values, without gaps in the ranks. The rank value starts at 1 and continues up sequentially. If two values are the same, they have the same rank. Parameters:
Example: Returns the dense rank of the row when the rows are sorted in an ascending order based on the value of "Revenue"-column: DenseRank([Column("Revenue")])
Same as the previous, except that the dense ranks are also partitioned by column "CaseId". DenseRank([Column("Revenue")], null, [Column("CaseId")])
|
| NTile | Divides an ordered dataset equally into defined number of buckets. Buckets are sequentially numbered 1 through the constant value. Parameters:
Example: Returns the bucket number of the row when the rows are sorted in an ascending order based on the value of Revenue column: NTile([Column("Revenue")])
Same as the previous, except that the buckets are also partitioned by column CaseId column: NTile([Column("Revenue")], null, [Column("CaseId")])
|
Window functions
The window functions are based on functionality provided by Snowflake (https://docs.snowflake.com/en/user-guide/functions-window-using) to aggregations for sliding or cumulative window of rows. To use the window functions, typically the following parameters need to be defined:
- expression: Expression that is calculated for each row and the window operation is done for the results.
- order by: Array of expressions to order the rows for the window operation.
- ascending: Array of boolean values to determine whether the ordering is done in ascending (true) or descending (false) order.
- partition by: Array of expressions to divide the data into different parts. The windowing operation is done separately for each part.
- window frame: The window frame parameter is a dictionary with properties described below.
Window frame dictionary parameters:
- Sliding: Used for the sliding window frame, i.e., a fixed number or rows in relation to the current row.
- Preceding: Number of preceding rows included into the window. If null, all the preceding rows in the partition are included. Default value is null.
- Following: Number of following rows included into the window. If null, all the following rows in the partition are included. Default value is null.
- Cumulative: Used for the cumulative window frame, i.e., calculate all rows either from start or end.
- UseRange (boolean): Should range (true) be used instead of rows (false). When the range is used, the window consists of all rows having same value in the sorting order. Default value is false.
- Following (boolean): Whether to calculate the cumulative values for preceding rows (true) or following rows (false). Default value is false.
| Function | Description |
|---|---|
| Average | Calculate average of values within given window. Parameters:
Example: Calculates average of values of Revenue column within a sliding window of 1 rows preceding and following the current row where window is partitioned by Id column and rows ordered by Year column: Average(Column("Revenue"), [Column("Year")], null, [Column("Id")], #{"Sliding": #{ "Preceding": 1, "Following": 1 }})
|
| Max |
Calculate maximum value within given window. Parameters:
Example: Calculates the maximum value of Revenue column within a sliding window of 3 rows preceding and the current row where window is partitioned by Id column and rows ordered by Year column: Max(Column("Revenue"), [Column("Year")], null, [Column("Id")], #{"Sliding": #{ "Preceding": 3 }})
|
| Median | Calculate median value within given window. Parameters:
Examples: Calculates median value of Revenue column partitioned by Id column: Median(Column("Revenue"), [Column("Id")])
|
| Min | Calculate minimum value within given window. Parameters:
Example: Calculates the minimum value of Revenue column within a cumulative window from the beginning where window is partitioned by Id column and rows ordered by Year column: Min(Column("Revenue"), [Column("Year")], null, [Column("Id")], #{"Cumulative": #{ "UseRange": false, "Following": false }})
|
| Sum | Calculate sum of values within given window.
Parameters:
Example: Calculates sum of the values of Revenue column within a cumulative window from the current row to the end where window is partitioned by Id column and rows ordered by Year column: Sum(Column("Revenue"), [Column("Year")], null, [Column("Id")], #{"Cumulative": #{ "UseRange": false, "Following": true }})
|
| ArrayAgg | Aggregates values by returning an array containing all the items. If the input has no rows, the function returns an empty array. This function is similar to the ListAgg function, except the type of the returned data is an array (not a string).
Parameters:
Example: Collects a list of order ID's starting from the highest Amount for each Month separately: ArrayAgg(Column("Order ID"), [Column("Amount")], [false], [Column("Month")])
|
| ListAgg | Returns the aggregated values as a string list where each item is separated by the defined delimiter. This function is similar to the ArrayAgg function, except the type of the returned data is a string (not an array).
Parameters:
Example: Collects a list of comma separated order ID's starting from the highest Amount for each Month separately: ListAgg(Column("Order ID"), ", ", [Column("Amount")], [false], [Column("Month")])
|
Array functions
| Function | Description |
|---|---|
| ArrayConcat | Combines two arrays together. Example:
ArrayConcat(["PO Item Created"], ["PR Created", "Invoice Payment"]) Returns: ["PO Item Created", "PR Created", "Invoice Payment"] |
| ArrayCompact | Removes nulls from an array. Example:
ArrayCompact([null, "a", null, "b"]) Returns: ["a", "b"] |
| ArrayContains | Checks whether given array contains given item. Returns true if item is found, or false if not found. Example:
ArrayContains("PR Created", ["PO Item Created", "PR Created", "Invoice Payment"])
Returns: true
|
| ArrayDistinct | Returns an array containing all distinct items of given array. The order of items in the returned array is not defined and may even vary between calls. Example:
ArrayDistinct([null, "a", "b", "b", "c", null]) Returns: ["a", "b", "c", null] |
| ArrayExcept | Returns an array containing items of the first array, except those that are present in the second array. The order of items in the returned array is not defined and may even vary between calls. Example:
ArrayIntersect(["A", "B", "C"], ["B", "D"]) Returns: ["A", "C"] |
| ArrayIntersect | Returns an array containing all items that appear in both parameter arrays. The order of items in the returned array is not defined and may even vary between calls. Example:
ArrayIntersect(["Invoice Created", "PO Item Created"], ["PO Item Created", "PR Created", "Invoice Payment"]) Returns: ["PO Item Created"] |
| ArraysOverlap | Returna true if both arrays have at least one common item, or otherwise returns false.
Examples: ArraysOverlap(["PR Created"], ["PO Created", "PR Created", "Invoice Payment"]) Returns: true ArraysOverlap(["Invoice Created", "Invoice Payment"], ["PO Created", "PR Created"]) Returns: false |
| ArrayPosition | Finds index of first occurrence of given item in given array. Returns null if the item doesn't exist in the array. Parameters:
Example: ArrayPosition("PR Created", ["PO Item Created", "PR Created", "Invoice Payment"])
Returns: 1
|
| ArraySize | Returns number of items in given array. Example:
ArraySize(["PO Item Created", "PR Created", "Invoice Payment"]) Returns: 3 |
| ArraySlice | Returns a specified range (or a slice) of given array. Parameters:
Example: ArraySlice([0, 1, 2, 3, 4, 5], 2, 4) Returns: [2, 3] |
| ArrayToString | Converts array into string by converting all individual items into strings and concatenating them using the separator character. Parameters:
Example: ArrayToString(["PO Item Created", "PR Created","Invoice Payment"], ", ") Returns: PO Item Created, PR Created, Invoice Payment |
| Split | Splits given string with given separator and returns the result in an array of strings. Parameters:
Example: Split("127.0.0.1", ".")
Returns: ["127", "0", "0", "1"]
|
Conformance checking functions
| Function | Description |
|---|---|
| IsConformant |
Checks conformance of a variation against a BPMN model (design model) and returns true if the variation conform to the model. Parameters:
Examples: Using the Array aggregation to evaluate variation: IsConformant(AggregateFrom(Events, #{{ "Function": "Array", "Ordering": [TimeStamp, EventType] }}, EventType), "<?xml...")
Using constant array as variation: IsConformant(["Sales order received", "Delivery planned", "Confirmed delivery date"], "<?xml...") |
| ConformanceViolationsFlows |
Checks conformance of variation against BPMN model (design model) and returns the first flow related violation if the variation was invalid. Returns null, if the variation is conformant. If the variation is nonconformant, returns a json string with properties s ("start") and e ("end") for the flow start and end event type names. When the flow is a starting flow, the s property is null, and when the flow is an ending flow, the e property is null. Parameters:
Example: ConformanceViolationsFlows(["Sales order received", "Delivery planned", "Confirmed delivery date"], "<?xml...", #{ "IncludeEventIndex": true} )
Example result: {
"s": "Invoice created",
"e": "Goods receipt",
"i": 3
}
|
AggregateFrom function
Aggregates a value from related objects, where there can be several of them a source object (e.g., when going from cases to events). See the type of relations between objects in the process mining concepts. The diagram shows that when going to direction where the target objects has count of N, AggregateFrom function needs to be used.
Parameters:
- Target objects: Target objects where to aggregate data from. Also an expression can be used to produce the dataset. Available aggregations are listed in table below (cardinality N).
- Aggregation: Aggregation function or object definition (see more).
- Expression: Expression to generate the values to be aggregated. Default value is null.
- Filter: Optional filter to apply prior to performing the aggregation. Filter is given as JSON like syntax using dictionaries, arrays and scalar values.
Example for EventTypes:
AggregateFrom(Events, "Count") Returns the number of events having each event type.
Example for Cases:
AggregateFrom(Events, #{ "Function": "List", "Ordering": ["TimeStamp"], "Separator": "#,#" }, Column("EventType"))
Returns variation/event type path string for all the cases.
GetValueFrom(Variations, AggregateFrom(Cases, "Count"))
Returns the number of cases having the same variation for every case.
DateDiff("Seconds", AggregateFrom(Events.Where(Column("EventType") == "Sales Order"), "Min", Column("TimeStamp")), AggregateFrom(Events.Where(Column("EventType") == "Invoice"), "Max", Column("Timestamp")))
Returns the duration in seconds between the first occurrence of "Sales Order"-event type and the last occurrence of "Invoice" event type for each case.
Example for Model:
AggregateFrom(Cases, "Count", null, #{"Items":[#{"Type":"IncludeCases","Items":[#{"Type":"CaseAttributeValue","Values":["Dallas"], "Attribute":"Region"}]}]})
Returns the total number of cases in the model having "Dallas" as the value of "Region" case attribute.
GetValueFrom function
Retrieves a value from a related object that there may be only one for a source object (e.g., when going from events to cases). See the type of relations between objects in the process mining concepts. The diagram shows that when going to direction where the target objects has count of 1, GetValueFrom function needs to be used.
Parameters:
- Target objects: Target objects where to get data from. This includes possible additional data frame expressions to prepare the aggregation level. Available aggregations are listed in table below (cardinality 1).
- Expression: Expression to evaluate in given aggregation level to get the returned value.
- Filter: Optional filter to apply prior to performing expression evaluation. Filter is given as dictionary following the JSON filter syntax.
Examples as measure expression for events:
GetValueFrom(Cases, Column("Account Manager\"))
Returns for each event the value of Account Manager case attribute.
GetValueFrom(Variations, Column("Variation"))
Returns for each event variation/event type path string of its case.
Examples as measure expression for events:
GetValueFrom(Variations, AggregateFrom(Cases, "Count"))
Returns the number of cases having the same variation for every case.
GetValueFrom(Cases, Column("Variation"), #{"Items":[#{"Type":"IncludeEventTypes","Items":[#{"Type":"EventType","Values":["Shipment","Invoice"]}]}]})
Returns cases with their variations where only "Shipment" and "Invoice" event types are taken into account.
AggregateRelatedValueFrom function
Gets data from other datatable where the there might be several rows in the target table for each row in the source table. Joins root expression with target table my matching joinMappings columns and applying aggregationFunction to target column.
Parameters:
- Target table: Datatable where to aggregate data from. Defined either as a datatable name or datatable object.
- Aggregation: Aggregate function used to aggregate the data.
- Expression: SQL expression which will be calculated for each row in the target table, and the results will then be aggregated.
- Joined columns: Columns that join the source data and the target datatable. If defined as an array of strings, assumes that the source and target have the same columns. If array of key-value pairs is defined, each pair describes a column in the source and a matching column in target datatable.
Example: Assuming root expression is Cases, returns the total sum for each order (case), aggregating from the "Order Lines" table:
AggregateRelatedValueFrom("Order Lines", "sum", Column("Cost"), ["SourceTableOrderId": "TargetTableOrderId"])
GetRelatedValueFrom function
Gets data from other table (called target table) that is linked to the source table. The relation to the target table must be N-to-1, i.e., there is only a single row in the target table corresponding a row in the source table. In practice, the function joins the source data with the target datatable based on the defined columns and returns a column value or calculates an SQL expression.
Parameters
- Target table: Datatable where to get data from. Defined either as a datatable name or datatable object.
- Expression: SQL expression to use as return value.
- Joined columns: Columns that join the source data and the target datatable. If defined as an array of strings, assumes that the source and target have the same columns. If array of key-value pairs is defined, each pair describes a column in the source and a matching column in target datatable.
Example: Assuming Events is the root, returns for each event the value of Region case attribute from "Cases" datatable.
GetRelatedValueFrom("Cases", Column("Region"), ["CaseIdInEvents": "CaseIdInCases"])
Example: If case id column name is same in cases and events table, the following can be used:
GetRelatedValueFrom("Cases", Column("Region"), ["CaseId"])
RelatedObjects function
Returns distinct objects that are linked to the current case through object-to-object relations. The function is a source aggregation level for the AggregateFrom function in DataFrame queries, i.e. AggregateFrom(RelatedObjects(...), ...) evaluates its nested expression once for each related object. RelatedObjects requires an object-centric model and a current Cases row, and it can be used only as an AggregateFrom source, not as a standalone scalar or source data expression.
The function supports the following forms:
- RelatedObjects(ObjectType)
- RelatedObjects(ObjectType, Qualifier)
- RelatedObjects(ObjectType, Qualifier, Direction)
- RelatedObjects(#{ ... }) - a configuration object with ObjectType, Qualifier, Direction, Path, and optional Filter properties.
Parameters:
- ObjectType: Object type of the related objects.
- Qualifier (optional): Relation qualifier to match. Can be a string, an array of strings, or null. null accepts all qualifiers.
- Direction (optional): Direction of the relations to follow. Supported values are Any, Outgoing, and Incoming. Default value is Any.
- Path (optional): Ordered relation steps to follow, where each step defines a target ObjectType and optional Qualifier and Direction. Returns the distinct objects reached by the final step.
- Filter (optional): Adds OcelItems object rules to the query's object rules. These select the final matched targets, not intermediate Path objects, without changing the outer case set.
Related-object events are directly linked events only. Perspective recursion depth, master-data object types, event-source object types, and event types do not restrict them, nor does the source object's lifetime.
An empty related-object set returns zero for the Count and CountDistinct aggregations and for Count with Distinct: true; other aggregations return null. This also applies to aggregation configuration objects and to results used in other expressions.
Available related-object columns, accessed using Column("column name"):
- OcelObjectId: Related object identifier.
- OcelObjectType: Related object type (the final target type when using Path).
- OcelObjectToObjectQualifier: Any matching qualifier from the final relation step. Multiple matches do not duplicate the object.
- Model-defined attributes from the Objects and the final target's ObjectType datatables, using their original names (for example, po_quantity). The GetObjectTypeAsCaseData function supplies the latest values and excludes OcelObjectTypeObjectId, OcelObjectTypeTime, and OcelObjectTypeChangedField.
Nested RelatedObjects calls start from the enclosing related object, whose attributes and events remain accessible. Unlike Path, nested aggregations process each enclosing object's related set separately. A nested AggregateFrom(Events, ...) exposes Column("OcelEventType") and Column("OcelEventTime"), and the role expressions EventType, TimeStamp, and CaseId identify the event type, timestamp, and related object. OcelEventId, event-to-object qualifiers, and custom event attributes are not exposed; custom attributes remain usable in query event filters.
Supported OcelItems object rules:
- ObjectAttributeValue and CaseCentric with FilterTarget: "Cases" (default) constrain related-object membership. CaseCentric uses the rule's perspective.
- CaseCentric targets Events and EventTypes affect neither related-object membership nor nested related-object events. Query-level rules may still affect outer perspective events; use event filters for nested events.
- Query object rules retain neighborhood-exclusion semantics, including exclusions of affected perspective objects.
- Query event selection operations, including IncludeEvents and ExcludeEvents attribute rules, also filter nested related-object events.
Filter configurations have the following distinct scopes:
- Query Filter: Selects perspective cases and also constrains related objects and their events.
- RelatedObjects(#{ ..., "Filter": ... }): Adds OcelItems rules to the query's object rules. These select final matched targets, not intermediate Path objects, without changing the outer case set.
- AggregateFrom's fourth filter argument: Applies supported Items selections to matched related-object data before aggregation. Related objects act as cases: a CaseAttributeValue filter on po_quantity selects Purchase Orders, not originating Purchase Requisitions. Event selections use the related-object columns described above.
The evaluation order is: originating cases, relation matching and deduplication, object rules, fourth-argument selections, nested expression, and aggregation back to each originating case. The fourth argument changes neither originating cases nor the relation path. Fourth-argument OcelItems do not filter RelatedObjects matches; use the configuration-level Filter.OcelItems instead. Local filters retain outer cases even when no targets survive, and empty-set results follow the rule above.
Examples: These expressions can be used as a value's Expression in an object-centric DataFrame query with Root set to Cases and Filter.Perspective.ObjectType set to Purchase Requisition. The model is assumed to contain the object types, relation qualifiers, and attributes used below.
Example: Count distinct outgoing Purchase Orders linked to each Purchase Requisition through PO from PR.
AggregateFrom(RelatedObjects("Purchase Order", "PO from PR", "Outgoing"), "Count")
Example: Sum the latest po_quantity attribute values of related Purchase Orders. The short form accepts both incoming and outgoing relations and all qualifiers by default.
AggregateFrom(RelatedObjects("Purchase Order"), "Sum", Column("po_quantity"))
Example: Sum the directly linked event counts of related Purchase Orders. An event linked to multiple related Purchase Orders contributes to each object's event count.
AggregateFrom(RelatedObjects("Purchase Order"), "Sum", AggregateFrom(Events, "Count"))
Example: Count distinct Invoices reached through Purchase Orders. An Invoice reached through multiple Purchase Orders is counted only once for each Purchase Requisition.
AggregateFrom(RelatedObjects(#{
"Path": [
#{ "ObjectType": "Purchase Order", "Qualifier": "PO from PR", "Direction": "Outgoing" },
#{ "ObjectType": "Invoice", "Qualifier": "Invoice from PO", "Direction": "Outgoing" }
]
}), "Count")
Example: Count the Invoices related to each Purchase Order, then sums those counts. Unlike a single Path, an Invoice shared by multiple Purchase Orders contributes to each Purchase Order's count.
AggregateFrom(RelatedObjects("Purchase Order"), "Sum",
AggregateFrom(RelatedObjects("Invoice"), "Count"))
Other functions
| Function | Description |
|---|---|
| CaseWhen |
Goes through conditions and returns a value when the first condition is true, similar to an if-then-else structure. Once a condition is true, it will stop reading and return the result. If no conditions are true, it returns the value in the else expression. If the else expression is not defined (i.e. there are even number of parameters), null value is returned. Consists of any number of pairs of condition and value expressions followed by an optional else expression. The odd parameters are the conditions and the even parameters are the return values. CaseWhen(Column("a") == null, 1, Column("a") < 1.0, 2, 3)
Returns 1 if the value of column "a" is null.
Returns 2 if the value of column "a" is less than 1.0.
Returns 3 otherwise.
Returns given value rounded to the nearest equal or larger integer. The data type should be one of the numeric data types. If the value is null, then the result is also null. |
| Coalesce |
Returns the first non-null parameter. There can be any number of parameters. If all parameters are null, returns null. Coalesce(null, 3, 2)
Returns 3.
Coalesce(Column("column1"), "N/A")
Returns column "column1" value, except replaces nulls with "N/A".
|
| Column |
Return the value of given column. Column("column1")
Column("My Column 2")
|
| GetObjectProperty |
Returns a sub-object in a key from an object. The first parameter is the object and the second parameter is the key path. This function returns an object (that's why string values contain quotation marks). This function doesn't work in SQL Server. Examples: GetObjectProperty(#{"key1": "value 1", "key2": 3 }, "key1")
Returns: "value 1"
GetObjectProperty(#{"key1": ["value 1", "value 2"] }, "key1[1]")
Returns: "value 2"
GetObjectProperty(#{"key1": [ #{"key2": 3 }, #{"key2": 4 } ] }, "key1[0].key2")
Returns: 3
GetObjectProperty(#{"key1": [ #{"key2": 3 }, #{"key2": 4 } ] }, "key1[0]")
Returns: { "key2": 3 }
|
| GetJsonValue |
Returns value of key from a json string. The first parameter is the json string and the second parameter is the key path. This function returns a string. This function works both in Snowflake and in SQL Server, but in SQL Server the returned value cannot be a json object. Examples: GetJsonValue("{\"key1\": \"value 1\", \"key2\": 3 }", "key1")
Returns: value 1
GetJsonValue("{\"key1\": [\"value 1\", \"value 2\"] }", "key1[1]")
Returns: value 2
GetJsonValue("{\"key1\": [ {\"key2\": 3 }, {\"key2\": 4 } ] }", "key1[0].key2")
Returns: 3
GetJsonValue("{\"key1\": [ {\"key2\": 3 }, {\"key2\": 4 } ] }", "key1[0]")
Returns: {"key2":3}
|
| IfNull |
If the first parameter is null, returns the second parameter, otherwise returns the first parameter. Functionality is the same as in the Coalesce function. Examples: IfNull(1, 2) // => 1
IfNull(null, 2) // => 2
IfNull(null, null) // => null
IfNull("abc", "def") // => "abc"
IfNull(null, "def") // => "def"
|
| In |
Returns true, if the test expression (given as the first parameter) matches with any of the other expressions given as parameters (starting from the seconds parameter). Examples: In(Column("Country"), "Germany", "France", "UK")
Return true if column "Country" is Germany, France or UK.
In("Germany", Column("SourceCountry"), Column("DestinationCountry"))
Returns true, if column SourceCountry or DestinationCountry is Germany (or both columns).
|
| LLMComplete |
Generates a response to the given prompt using a large language model (LLM). This function uses the Snowflake's SNOWFLAKE.CORTEX.COMPLETE function (https://docs.snowflake.com/en/sql-reference/functions/complete-snowflake-cortex). Parameters can be given either as a short syntax (model name + prompt as string), or a long syntax (model name + prompt as array + options). Parameters:
Return value type depends on whether the short or long syntax has been used. For the short syntax, return value is a string. For the long syntax, return value is an object containing the response and related details. Example (short syntax): LlmComplete(
"mixtral-8x7b",
Concat("Explain the given product group: ", Column("Product Group"))
)
Example (long syntax): Cast(
LlmComplete(
"snowflake-arctic",
[
#{
"role": "system",
"content": "Explain the given product group."
},
#{
"role": "user",
"content": Column("Product Group")
}
],
#{
"temperature": 0
}
)["choices"][0]["messages"],
"string"
)
The above example also shows how the extract the text from the response object. |
| NullIf |
Returns null if the first parameter equals the second parameter, otherwise returns the first parameter. Examples: NullIf(1, 1) // => null
NullIf(1, 2) // => 1
NullIf("abc", "abc") // => null
NullIf("abc", "def") // => "abc"
NullIf(null, 1) // => null
NullIf(1, null) // => 1
Example: Avoid dividing by zero - the following expression returns null if Column("B") is zero: Column("A") / NullIf(Column("B"), 0)
|
| Variable |
Gets variable value available in the in-memory expression context where the SQL expression is run. Supports string, number, boolean and date values. In addition, the variable can contain SQL expression which is added as such to the contained SQL expression. Example of an in-memory expression having SQL expression in the Where function: let myRegion = "Dallas";
DatatableById(123)
.SqlDataFrame
.Where(Column("Region") == Variable("myRegion"))
.Collect()
Filters datatable by Region is Dallas.
Note that in the above example Column("Region") == Variable("myRegion") is the SQL expression. |
Process mining objects, properties and aggregations
The following table summarizes the available process mining objects and which properties and aggregations are available for them. For aggregations, the AggregateFrom function is used with cardinality N aggregations and the GetValueFrom function with the cardinality 1 aggregations.
| Object type | Properties | Aggregations (cardinality in parenthesis) |
|---|---|---|
| Cases |
|
|
| Events |
|
|
| EventTypes |
|
|
| Variations |
|
|
| Flows |
|
|
| FlowOccurrences |
|
|
| Model |
|
|
Root expression examples:
For cases (and also events), the case id can be referred using CaseId:
Cases.Where(CaseId == "Case_123")
Assuming that there is an Order Id column that is mapped to the CaseId, also the original column name can be used:
Cases.Where(Column("Order Id") == "Case_123")
For events, the event type can be referred using EventType:
Events.Where(EventType == "Order created")
Assuming that there is an Process step column that is mapped to the EventType, also the original column name can be used:
Cases.Where(Column("Process step") == "Order created")
Aggregation operations
Aggregations are used when multiple items or rows are combined into a single value. The following aggregations are available:
- Sum: Sum of the items. Can be used for numbers.
- Average: Average of the items (sum of items divided by count of items). Can be used for numbers.
- Median: The middle value of the sorted data. If there are even number of items, the average of the two middle items. Can be used for numbers.
- Min: Lowest value for numbers, alphabetically first value for texts and earliest value for dates.
- Max: Highest value for numbers, alphabetically last value for texts and last value for dates.
- Count: Number of items. Can be used for any type of data.
- CountDistinct: Number of unique items (i.e., duplicates are removed). Can be used for any type of data.
- Percentile: Percentile value. Can be used for numbers. Percentile aggregation has following parameter:
- Percentile: Percentile value between 0 and 1.
Can be defined as an object as follows:
#{ "Function": "Percentile", "Percentile": 0.75 }
- Stdev: Sample standard deviation. Can be calculated for numbers.
- Stdevp: Population standard deviation. Can be calculated for numbers.
- Var: Sample variance. Can be used for numbers.
- Varp: Population variance. Can be used for numbers.
- List: Combines textual values into a single list in defined order and separated by defined characters. List aggregation has following parameters:
- Ordering: Array of columns defining how items are ordered. Ordering is supported only when Distinct is false.
- Separator: Characters separating the combined items.
- Distinct: Whether duplicate items are removed. Default value is false. When showing distinct items, the items are sorted by their values.
Can be defined as an object as follows:
#{ "Function": "List", "Ordering": [EventType], "Separator": ", ", "Distinct": true }
- Any: Returns any value of the aggregated values. This is the most efficient aggregation when it's known that there is maximum of one value among the aggregated values. Note that there is no guarantee that the returned value will be the same every time.
- Array: Returns the aggregated values as a single array object. This aggregation has following parameters:
- Ordering: Array of columns defining how items are ordered.
- Distinct: Whether duplicate items are removed. Default value is false. When showing distinct items, the items are sorted by their values.
- MinBy: Finds a row containing the minimum value for the defined column and returns the value of another column in that row. The aggregation has the following parameter:
- Ordering: One column in an array defining from which column the minimum is determined.
Can be defined as an object as follows:
#{ "Function": "MinBy", "Ordering": ["Cost"] }
- MaxBy: Finds a row containing the maximum value for the defined column and returns the value of another column in that row. The aggregation has the following parameter:
- Ordering: One column in an array defining from which column the maximum is determined.
Can be defined as an object as follows:
#{ "Function": "MaxBy", "Ordering": ["Cost"] }