DocumentDB SQL - Array Function

The array functions perform an operation on an array input value and return in the form of numeric, Boolean or array value. Following are the built-in array functions.

S.No.	Function & Description
1	ARRAY_LENGTH (arr_expr) Returns the number of elements of the specified array expression.
2	ARRAY_CONCAT (arr_expr, arr_expr [, arr_expr]) Returns an array that is the result of concatenating two or more array values.
3	ARRAY_CONTAINS (arr_expr, expr) Returns a Boolean indicating whether the array contains the specified value.
4	ARRAY_SLICE (arr_expr, num_expr [, num_expr]) Returns part of an array expression.

Let’s take a look at another example where some built-in array functions are used.

Following is the query with different array functions.

SELECT 
   ARRAY_CONCAT(["A", "B"], ["1", "2"], ["#"]) AS ArrConcat, 
   ARRAY_CONTAINS(["1A", "1B", "1C"], "1B") AS ArrContains, 
   ARRAY_LENGTH(["1A", "1B", "1C"]) AS ArrLength, 
   ARRAY_SLICE(["1A", "1B", "1C", "1D"], 1, 2) AS ArrSlice

When the above query is executed, it produces the following output.

[ 
   { 
      "ArrConcat": [ 
         "A", 
         "B", 
         "1", 
         "2", 
         "#" 
      ],
	  
      "ArrContains": true,
      "ArrLength": 3, 
      "ArrSlice": [ 
         "1B", 
         "1C" 
      ] 
   } 
]

documentdb_sql_builtin_function.htm