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MAP_SIZE

Description​

Calculates the number of elements in a Map

Syntax​

MAP_SIZE(<map>)

Parameters​

  • <map> MAP type, the input map content.

Return Value​

Returns the number of elements in the Map

Usage Notes​

  1. Both NULL keys and values are counted.
  2. For NULL parameters, returns NULL.

Examples​

  1. Regular parameters

    select map_size(map()), map_size(map(1, "100", 0.1, 2, null, null));
    +-----------------+---------------------------------------------+
    | map_size(map()) | map_size(map(1, "100", 0.1, 2, null, null)) |
    +-----------------+---------------------------------------------+
    | 0 | 3 |
    +-----------------+---------------------------------------------+
  2. NULL parameters

    select map_size(NULL);
    +----------------+
    | map_size(NULL) |
    +----------------+
    | NULL |
    +----------------+