| Excerpt |
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Merges two or more columns of String type to generate output of String type. Optionally, you can insert a delimiter between the merged values. |
| Info |
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NOTE: This function behaves exactly like the merge transform, although the syntax is different. See Merge Transform. |
String literal reference example:
| D lang syntax |
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| RawWrangle | true |
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| Type | ref |
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| showNote | true |
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| WrangleText | derive type:single value:merge(['Hello,','World'],' ') as:'Hi' |
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|
merge(['Hello,','World'],' ') |
Output: Returnsthe value Hello, World.
Column reference example:
| D lang syntax |
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| RawWrangle | true |
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| Type | ref |
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| showNote | true |
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| WrangleText | derive type:single value:merge([string1,string2]) as:'merged_strings' |
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merge([string1,string2]) |
Output: Returns a single String value that is the merge of string1 and string2 values.
| D lang syntax |
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| RawWrangle | true |
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| Type | syntax |
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| showNote | true |
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| WrangleText | derive type:single value:merge([string_ref1,string_ref2],'string_delim') |
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merge([string_ref1,string_ref2],'string_delim') |
| Argument | Required? | Data Type | Description |
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| string_ref1 | Y | string | Name of first column or first string literal to apply to the function |
| string_ref2 | Y | string | Name of second column or second string literal to apply to the function |
| string_delim | N | string | Optional delimiter string to insert between column or literal values |
string_ref1, string_ref2
String literal or name of the string column whose elements you want to merge together. You can merge together two or more strings.
| Required? | Data Type | Example Value |
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| Yes | String literal or column reference | myString1, myString2 |
string_delim
Optional string literal to insert between each string that is being merged.
| Required? | Data Type | Example Value |
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| No | String literal | '-' |
Example - Simple merge example
The following example contains the names of a set of American authors. You need to bring together these column values into a new column, called FullName.
Source:
| FirstName | LastName | MiddleInitial |
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| Jack | Kerouac | L |
| Paul | Theroux | E |
| J.D. | Salinger | |
| Philip | Dick | K |
Transformation:
| D trans |
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| RawWrangle | true |
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| p03Value | 'FullName' |
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| Type | step |
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| WrangleText | derive type:single value:merge([FirstName,MiddleInitial,LastName],' ') as:'FullName' |
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| p01Name | Formula type |
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| p01Value | Single row formula |
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| p02Name | Formula |
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| p02Value | merge([FirstName,MiddleInitial,LastName],' ') |
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| p03Name | New column name |
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| SearchTerm | New formula |
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Since the entry for J.D. Salinger has no middle name, you might want to add the following transformation:
| D trans |
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| RawWrangle | true |
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| p03Value | '' |
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| Type | step |
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| WrangleText | replace col:FullName with:' ' on:' ' |
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| p01Name | Column |
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| p01Value | FullName |
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| p02Name | Find |
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| p02Value | ' ' |
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| p03Name | Replace with |
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| SearchTerm | Replace text or pattern |
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|
Results:
| FirstName | LastName | MiddleInitial | FullName |
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| Jack | Kerouac | L | Jack L Kerouac |
| Paul | Theroux | E | Paul E Theroux |
| J.D. | Salinger | | J.D. Salinger |
| Philip | Dick | K | Philip K DIck |
Other Examples
While the syntax may be different, the MERGE function behaves exactly like the merge transform. For more examples, see Merge Transform.
