Extended Metadata (FireDAC)

From Appmethod Topics
Jump to: navigation, search

Go Up to Working with Metadata (FireDAC)


To enable this feature, you must set the connection definition parameter ExtendedMetadata to True. The table below lists the DBMSs:

DBMS Description
IBM DB2
  • Origin table and column name for each item in select list;
  • Columns updatability;
  • Columns auto-incrementing mode.
Firebird, InterBase
  • Columns with domain %BOOL% are recognized as ftBoolean;
  • Columns with domain %GUID% are recognized as ftGUID;
  • When the table has a BEFORE INSERT trigger, which depends on a single sequence and a single table column, this column is recognized as ftAutoInc;
  • Columns GENERATED BY DEFAULT AS IDENTITY are recognized as ftAutoInc;
  • Columns COMPUTED BY are recognized as TField.AutoGenerateValue = arDefault.
PostgreSQL
  • Origin table and column name for each item in select list;
  • Columns optionality;
  • Columns updatability;
  • Columns with domain LO, LARGEOBJECT or BLOB are recognized as ftOraBlob (BLOB handled by the reference);
  • Columns with DEFAULT NEXTVAL('xxx') are recognized as ftAutoInc;
  • Columns with other default values are recognized as [caDefault];
  • Columns with system OID are recognized as [caROWID].
SQL Server
  • Origin table and column name for each item in select list.

Extended metadata recognition is supported only for the dataset columns and not for the mkTableFields metadata request.

Note: ExtendedMetadata=True executes additional queries. That may decrease application performance.

See Also