PostgreSQL generate_subscripts() Function

The PostgreSQL generate_subscripts() function returns a set of array subscripts according to the specified array and dimensions.

`generate_subscripts()` Syntax

Here is the syntax of the PostgreSQL generate_subscripts() function:

generate_subscripts(arr array, dim integer[, reverse boolean]) -> setof integer

arr: Required. It can be an array of any type.
dim: Required. The dimension of the array.
reverse: Optional. If returns the subscripts array in reverse order. The default value is false.

The PostgreSQL generate_subscripts() function returns a set of subscripts of the specified array dimension.

Here are some examples of the generate_subscripts() function.

To return all subscripts of the {3, 4, 5, 7}, use the following statement:

SELECT generate_subscripts('{3, 4, 5, 7}'::int[], 1);

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To return all subscripts of the array {3, 4, 5, 7} in reverse order, use the following statement:

SELECT generate_subscripts('{3, 4, 5, 7}'::int[], 1, true);

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To return all subscripts of the first dimension of the two-dimensional array {{3, 4, 5}, {7, 8, 9}}, use the following statement:

SELECT generate_subscripts('{{3, 4, 5}, {7, 8, 9}}'::int[][], 1);

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To return all subscripts of the second-dimensional array in a two-dimensional array {{3, 4, 5}, {7, 8, 9}}, use the following statement:

SELECT generate_subscripts('{{3, 4, 5}, {7, 8, 9}}'::int[][], 2);

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