FAQ - Question #10

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Q. I have varchar and text fields in my query. When I try to use them in filter error occurred: "Cannot access field '%name%' in a filter"

A. Type text is the most used return type for string functions and operators, e.g. concatenation, convertion, trimming etc. are always returned as text. User defined types are treated as text in PostgresDAC also.

Text, varchar without length and varchar(>8192) types are treated by PostgresDAC as TMemoField. This affects in a different ways. First of all, TMemoField is a descendant of TBlobField which means that all in/out operations will be done using TStream descendants.

Filters cannot operate BLOB fields. Thus it's better to use implicit type casting.

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