Foxpro server sql updating
The SQL UPDATE and SQL DELETE commands now support correlation.
A correlated statement includes a FROM clause to relate the records being affected to another table.
The total number of items is still indirectly limited by the SYS(3055) function, which controls buffer memory size, so the higher the setting, the more items are supported via IN.
(See the Common Error Messages sidebar for more information.)No hard-coded limits does not mean limitless.
A single SQL SELECT statement can contain more tables, more JOINs, more sub-queries, more nested sub-queries, and more UNIONs than ever before.
Changes to the data engine can be summarized in five major areas: Many of these changes improve the Visual Fox Pro 9 client/server story by providing stronger interoperability with SQL Server.
SELECT ; C.customer ID, ; C.companyname, ; SUM(D.quantity*D.unitprice) AS Cust Total ,; (SUM(D.quantity*D.unitprice) / ; (SELECT SUM((quantity*unitprice)-discount) ; FROM Order Details D2) ; )*100 AS Pct Total ; FROM Customers C ; INNER JOIN Orders O ; ON C.customer ID = O.customer ID ; INNER JOIN Order Details D ; ON O.orderid = D.orderid ; GROUP BY C.customer ID, C.companyname, O.order ID ; ORDER BY pct Total DESC This SELECT statement returns customer ID, company name, total sales, and a percent of total sales against all customer sales.
Most evident in several changes to the data engine, Visual Fox Pro 9 includes many enhancements for data access and database application development.In versions prior to Visual Fox Pro 9, SQL IN was mapped to the INLIST() function; that dependency has been removed.This change allows an increase in the number of arguments for IN and for better optimization.Many of these changes improve Fox Pro's client/server capabilities by providing stronger interoperability with SQL Server.When used as a projection, if the sub-query doesn't return any records, a NULL value is returned.