Subscripted expressions

Use subscripted expressions to access elements in a multi-element value, such as a map collection by using operator []. Subscripted column expressions can be used when writing the same way as a column expression. For example, if ids refers to a column of type LIST, ids[7] refers to the third element of the list ids, which can be set in an UPDATE statement.

  • Subscripted expression can only be applied to columns of type LIST, MAP, or user-defined data types.
  • Subscripting a LIST value with a non-positive index will yield NULL.
  • Subscripting a MAP value with a non-existing key will yield NULL. Otherwise, it returns the element value that is associated with the given key.
  • Apache Cassandra does not allow subscripted expression in the select list of the SELECT statement.

Examples

ycqlsh:yugaspace> CREATE TABLE t(id INT PRIMARY KEY,yugamap MAP<TEXT, TEXT>);

ycqlsh:yugaspace> UPDATE yugatab SET map_value['key_value'] = 'yuga_string' WHERE id = 7;

See also