This structure contains any expression, either as a value (the value
part is set), a variable (the param_spec
is set), or as other types of expressions.
Note 1 about the value
field: if the expression represents a string value in the SQL statement, the string itself must be
represented as it would be in the actual SQL, ie. it should be escaped (accordingly to the escaping rules of the database which will use
the SQL). For example a string representing the <userinput>'joe'</userinput> value should be <userinput>"'joe'"<
/userinput> and not <userinput>"joe"</userinput>.
Note 2 about the value
field: if the expression represents an SQL identifier (such as a table or field name), then the
value_is_ident
should be set to true, and value
should be a string which may
contain double quotes around SQL identifiers which also are reserved keywords or which are case sensitive.