Properties and Options of MergeFileDescription

+———————-+———————————————-+ |Property name | Description | +======================+==============================================+ | FileName | The names of the files to be merged. | | | “Active file” means the file current | | | active dataset. | +———————-+———————————————-+ | _ | | +———————-+———————————————-+ | MergeType | Describes the type of merge performed. | +———————-+———————————————-+ | | > Sequential: Match rows from each input | | | > dataframe in sequential order. | | | > | | | > OneToOne: Create one row for each value of | | | > the mergeByVariables. If a combination | | | > of the mergeByVariables is repeated, | | | > only one row is matched. Rows with | | | > repeated combinations of the | | | > MergeByVariables may or may not be | | | > included in the output file depending on | | | > the newRow property. | | | > | | | > OneToMany: Create a row in the output | | | > dataframe by matching rows in this | | | > dataframe to every row in other dataframes | | | > with the same value of MergeByVariables. | | | > Note that OneToMany implies that one of | | | > the other input datarames is set to | | | > ManyToOne. | | | > | | | > ManyToOne: Create a row in the output | | | > dataframe by matching all rows in this | | | > dataframe to the one row in the other | | | > dataframe with the same value of | | | > MergeByVariables. | | | > | | | > Cartesian: Create a new row in the output | | | > dataframe for every possible combination | | | > of rows having the same value of | | | > MergeByVariables. This is equivalent to a | | | > many to many merge. R and Python use a | | | > model derived from SQL, which is based on | | | > Cartesian joins. | | | > | | | > Unmatched: Create a new row for every row | | | > that cannot be matched on the | | | > MergeByVariables | | | > | | | > SASmatchMerge: SAS uses a merging approach | | | > that combines matching keys and sequential | | | > merges within groups. | +———————-+———————————————-+ | MergeFlagVariable | Creates a new variable indicating whether | | | the row came from this file or a different | | | input file. | +———————-+———————————————-+ | RenameVariables | Variables to be renamed | +———————-+———————————————-+ | _ | | +———————-+———————————————-+ | Update | Describes outcome when a variable exists in | | | both this file and another file. | +———————-+———————————————-+ | | > Master: This dataframe is the Master | | | > dataframe. | | | > | | | > Ignore: If a column with the same name | | | > exists in the Master dataframe, ignore the | | | > values in this dataframe. | | | > | | | > FillNew: If a column with the same name | | | > exists in the Master dataframe, use the | | | > values from this dataframe only in new | | | > rows created from this dataframe. | | | > | | | > UpdateMissing: If a column with the same | | | > name exists in the Master dataframe, use | | | > values from this dataframe when the value | | | > in the Master dataframe is missing. Rows | | | > not in the Master dataframe are filled | | | > from this dataframe. | | | > | | | > Replace: If a column with the same name | | | > exists in the Master dataframe, use values | | | > from this dataframe. | +———————-+———————————————-+ | NewRow | When TRUE, generates a new row when not | | | matched to other files | +———————-+———————————————-+ | KeepVariables | List of variables to keep | +———————-+———————————————-+ | DropVariables | List of variables to drop | +———————-+———————————————-+ | KeepCasesCondition | Logical condition for keeping rows. | +———————-+———————————————-+ | DropCasesCondition | Logical condition for dropping rows. | +———————-+———————————————-+