NOT_A_CONSTANT_STRING error class
The expression <expr> used for the routine or clause <name> must be a constant STRING which is NOT NULL.
This error class has the following derived error classes:
NOT_CONSTANT
To be considered constant the expression must not depend on any columns, contain a subquery, or invoke a non deterministic function such as rand().
NULL
The expression evaluates to NULL.
WRONG_TYPE
The data type of the expression is <dataType>.