Data Retrieval Support

In response to read and selectdb ProcScript instructions, Uniface issues connector requests to select data into a hitlist and fetch it into the calling component. Special considerations and restrictions may apply for some databases.

  • Most databases support stepped hitlists to improve performance.
  • For some databases, the use of selectdb functions may be restricted, depending on the DBMS data type of the field.
  • The offset option of the read ProcScript statement is not supported by all connectors.
  • Record-level databases do not support the where, order by, and u_where arguments to the read statement or the retrieveSequential trigger.

For more information, see read and selectdb. For details about the data retrieval support provided by specific connectors, see the following table.

Data Retrieval Support

Connector

Stepped hitlist?

where  

order by

u_where  

offset

selectdb

retrieveSequential Trigger

Details

DB2

Yes

Yes

Yes

Yes

Yes

Yes

Yes

For more information, see Data Retrieval on DB2.

Informix

Yes

Yes

Yes

Yes

No

Yes

Yes

For more information, see Data Retrieval on Informix.

LDAP

Yes

Yes

Yes

Yes

No

Yes

Yes

For more information, see Data Storage and Retrieval on LDAP and Map LDAP Entries to Uniface Entities.

MS-SQL Server

Yes

Yes

Yes

Yes

Yes

Yes

Yes

For more information, see Data Retrieval on Microsoft SQL Server .

MySQL

Yes

Yes

Yes

Yes

Yes

Yes

Yes

For more information, see Data Retrieval on MySQL.

ODBC

Yes

Yes

Yes

Yes

No

Yes

Yes

For more information, see Data Retrieval on ODBC.

Oracle

Yes

Yes

Yes

Yes

Yes

Yes

Yes

For more information, see Data Retrieval on Oracle.

PostgreSQL

Yes

Yes

Yes

Yes

Yes

Yes

Yes

 

SEQ

No

No

Yes

Yes

No

Yes

No

For more information, see Data Retrieval on SEQ.

SQLite

Yes 1

Yes

Yes

Yes

Yes

Yes

Yes

For more information, see Data Retrieval on SQLite and Locking Considerations for SQLite.

Sybase

Yes

Yes

Yes

Yes

No

Yes

No

For more information, see Data Retrieval on Sybase .

TXT

No

No

No

No

No

No

 

 

  1. By default, stepped hitlists are disabled. For more information, see Locking Considerations for SQLite.

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