OpenEdge Data Management:<br />DataServer for ODBC FIND statements

The DataServer fully supports the FIND FIRST, CURRENT, LAST, PREV, and NEXT statements for ODBC data-source tables that have unique indexes. If a table has no unique index, only the FIND FIRST and FIND NEXT statements are available for that table. The following section provides additional information about specific FIND statements.

FIND PREV and FIND LAST statements

Applications that use the FIND PREV or FIND LAST statements work on ODBC data-source tables in a manner consistent with OpenEdge. The only exception occurs when the FIND PREV or FIND LAST statement fails. In the OpenEdge case, the cursor is located after the last record that was scanned. In the data-source case, the cursor behaves as if the failed FIND had never occurred. To support these statements, a data-source table must include support for the Progress ROWID function (through either a PROGRESS_RECID column or an indexed NUMBER column with unique values). See the "ROWID function" section for more information.

For example, the procedure find.p accesses OpenEdge databases and ODBC data sources using the same FIND and FIND PREV statements in each case:

find.p
/* This code accesses an OpenEdge database. / FIND demo.customer WHERE demo.customer.cust-num = 3. FIND PREV demo.customer. DISPLAY demo.customer.cust-num LABEL "PROGRESS DATABASE RESULT" WITH FRAME new-frame. / This code accesses an ODBC data source. */ FIND odbcdemo.customer WHERE odbcdemo.customer.cust-num = 3. FIND PREV odbcdemo.customer. DISPLAY odbcdemo.customer.cust-num LABEL "ODBC DATA SOURCE RESULT" WITH COL 29

find.p

/* This code accesses an OpenEdge database. */
FIND demo.customer WHERE demo.customer.cust-num = 3.
FIND PREV demo.customer.
DISPLAY demo.customer.cust-num
  LABEL "PROGRESS DATABASE RESULT" WITH FRAME new-frame.

/* This code accesses an ODBC data source. */
FIND odbcdemo.customer WHERE odbcdemo.customer.cust-num = 3.
FIND PREV odbcdemo.customer.
DISPLAY odbcdemo.customer.cust-num
  LABEL "ODBC DATA SOURCE RESULT" WITH COL 29

When you run find.p with an OpenEdge table and a data-source table, you get these results (assuming that the database has records for customer numbers 1 through 4):

If the FIND PREV statement fails, the cursor remains located after customer.cust-num 3 in the OpenEdge table, which was the last record scanned. In the data-source table, the cursor is positioned at cust-num 2. Failed finds do not affect cursor position in data-source tables.

FIND NEXT statement

The FIND NEXT statement can generate different results when you use it to access an ODBC data source through the DataServer than when you use it to access an OpenEdge database. When accessing an ODBC data source:

A FIND NEXT statement refers to a previous FIND statement if the WHERE clauses in both statements are identical.

If the WHERE clauses are different, or if one of the statements does not have a WHERE clause, the FIND NEXT statement behaves like a FIND FIRST statement.