OpenEdge Data Management: DataServer for Microsoft SQL Server
OpenEdge Data Management: DataServer for Microsoft SQL Server
OpenEdge Data Management: DataServer for Microsoft SQL Server
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Initial Programming Considerations<br />
2–56<br />
The following code will not return a run time error because the CAN-FIND expression resolves<br />
to FALSE, masking the fact that there was in fact no customer.st value to compare:<br />
FOR EACH customer FIELDS (custnum name)<br />
WHERE customer.name EQ "Off the Wall" NO-LOCK:<br />
CAN-FIND(FIRST order WHERE order.st = customer.st NO-LOCK).<br />
END.<br />
See the “Record Phrase” entry in <strong>OpenEdge</strong> Development: ABL Reference <strong>for</strong> more in<strong>for</strong>mation<br />
on the FIELDS option.<br />
FIND statements<br />
The <strong>Data</strong><strong>Server</strong> fully supports the FIND FIRST, CURRENT, LAST, PREV, and NEXT statements <strong>for</strong><br />
MS <strong>SQL</strong> <strong>Server</strong> data source tables that have unique indexes. If a table has no unique index, only<br />
the FIND FIRST and FIND NEXT statements are available <strong>for</strong> that table. The following section<br />
provides additional in<strong>for</strong>mation about specific FIND statements.<br />
FIND NEXT statement<br />
The FIND NEXT statement can generate different results with the <strong>Data</strong><strong>Server</strong> when compared to<br />
the same statement executed against an <strong>OpenEdge</strong> database. A FIND NEXT statement refers to a<br />
previous FIND statement only if the WHERE clauses of each statement are identical. If the WHERE<br />
clauses are different, or if one of the statements does not have a WHERE clause, the FIND NEXT will<br />
behave like a FIND FIRST statement.<br />
FIND PREV and FIND LAST statements<br />
Applications that use the FIND PREV or FIND LAST statements work on tables in a manner<br />
consistent with the <strong>OpenEdge</strong> database. The only exception occurs when the FIND PREV or FIND<br />
LAST statement fails. In <strong>OpenEdge</strong>, the cursor is located after the last record that was scanned.<br />
In the MS <strong>SQL</strong> <strong>Server</strong> data source, the cursor behaves as if the failed FIND had never occurred.<br />
To support these statements, a table must include support <strong>for</strong> the <strong>OpenEdge</strong> ROWID function<br />
(through either a PROGRESS_RECID column or an indexed NUMBER column with unique values).<br />
See the “ROWID function” section on page 2–52 <strong>for</strong> more in<strong>for</strong>mation.<br />
For example, the procedure find.p accesses <strong>OpenEdge</strong> and MS <strong>SQL</strong> <strong>Server</strong> databases using<br />
the same FIND and FIND PREV statements in each case, as shown:<br />
find.p<br />
/* This code accesses an <strong>OpenEdge</strong> database. */<br />
FIND demo.customer WHERE demo.customer.custnum EQ 3.<br />
FIND PREV demo.customer.<br />
DISPLAY demo.customer.custnum<br />
LABEL "PROGRESS DATABASE RESULT" WITH FRAME new-frame.<br />
/* This code accesses a MS <strong>SQL</strong> <strong>Server</strong> data source.*/<br />
FIND mssdemo.customer WHERE mssdemo.customer.custnum EQ 3.<br />
FIND PREV mssdemo.customer.<br />
DISPLAY mssdemo.customer.custnum<br />
LABEL "MSS DATA SOURCE RESULT" WITH COL 29.
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