checkExpression

The expression which includes column references, condition names followed by variable references, possibly grouped and combined with other conditions. For example, (:col1 starts_with :prefix1 or :col1 starts_with :prefix2) and (:col1 ends_with :suffix1 or :col1 ends_with :suffix2) . Column and value references are substitution variables that should start with the ':' symbol. Depending on the context, substitution variables' values can be either an actual value or a column name. These values are defined in the SubstitutionMap. If a CheckExpression starts with a column reference, then ColumnSelectors in the rule should be null. If ColumnSelectors has been defined, then there should be no columnn reference in the left side of a condition, for example, is_between :val1 and :val2 .