MAP

The MAP function is used to create a key-value mapping table, where each key corresponds to a value. This data structure allows for convenient storage and retrieval of data associated with specific keys.

Syntax

MAP <keyType, valueType> (key1, value1, key2, value2, ...)

Parameters

• keyType: The type of the key, which can be any basic data type such as integer, string, etc.
• valueType: The type of the value, which can be any basic data type such as integer, string, etc.
• (key1, value1, key2, value2, ...): One or more key-value pairs, separated by commas.

Example

1. Map color names to corresponding numbers:

 CREATE TABLE   MAP_TABLE(COL MAP<STRING,INT>);
SELECT MAP ('red', 1, 'green', 2);
 +---------------------------+

 | MAP('red', 1, 'green', 2) |

 +---------------------------+

 | {"red":1,"green":2}       |

 +---------------------------+

2. Map employee names to their corresponding departments:

   SELECT MAP ('Alice', 'HR', 'Bob', 'Sales', 'Charlie', 'IT');
    +-----------------------------------------------------+
    | MAP('Alice', 'HR', 'Bob', 'Sales', 'Charlie', 'IT') |
    +-----------------------------------------------------+
    | {"Alice":"HR","Bob":"Sales","Charlie":"IT"}         |
    +-----------------------------------------------------+
   

3. Map the exam scores to the corresponding grades:

SELECT MAP (60, 'Pass', 80, 'Good', 90, 'Excellent');
 +-----------------------------------+
 | MAP(60, 'Pass', 80, 'Good', 90, 'Excellent') |
 +-----------------------------------+
 | {60:"Pass",80:"Good",90:"Excellent"}         |
 +-----------------------------------+