Vfp sqlexec cursor read write and think

On the other hand, if table size is about but less than 2Gb and there are a substantial number of simultaneous sessions, FoxPro productivity becomes inferior to that of SQL Server.

For example, assume a SQL Server table has an Autoincrement primary key column Custid and supplies a default value for the Dateadded column. So you actually only need to act on the cursor, as if it was a buffered DBF file instead of coming from a remote database. If it does, how much does it need it? In other words, if you use up all available memory, you'll end up with a slowest application, as optimization becomes unavailable. We'll begin with the connection and gathering of the data first. If another user changed Custname for this same record in the meantime, no records will match and the update fails. In the first tab 1. In other words, the above option only works for a single language, which might be fine for an application that has to work only with a single language at a time. It would be easier to make separate applications for these locations using a simple FoxPro-based Automation server, than to update all the code of your application to SQL Server syntax. It also has a Refresh timestamp checkbox on the Fields Refresh page of the new Refresh Properties dialog see Figure 3 that allows you to set the RefreshTimeStamp property.

Timestamp support When you create a remote view with the WhereType property set to 4 Key and timestampVFP automatically determines which field in the remote table is timestamp-compatible and saves this information in the view definition.

If another user changed Custname for this same record in the meantime, no records will match and the update fails.

vfp create cursor read write

RefreshAlias contains the name of the read-only cursor opened temporarily by VFP during a RecordRefresh to hold the data retrieved from the data source. Note that I did not do this on purpose.

Yet, don't let this simplicity fool you. In VFP 8, the CursorAdapter allows you to set WhereType to 4, but does not have the capability to determine which column in the remote table was a timestamp. We'll begin with the connection and gathering of the data first. I will explore these topics together with you as a VFP engineer in blog entries to come. It's much easier to select the data into FoxPro cursors, as we cannot doubt FoxPro abilities when used as a remote server in "Client-Server" technology. The landscape is limited solely by your own imagination and technical prowess. Especially if you make this class a base class for all further cursoradapters this means only specifying this once and be able to change it at one place later. Also, if you make distributed products, SQL Server compatibility will be one of the first evaluation criteria. It also has a Refresh timestamp checkbox on the Fields Refresh page of the new Refresh Properties dialog see Figure 3 that allows you to set the RefreshTimeStamp property. Microsoft may work really hard on developing ADO. If BatchUpdateCount is set to a number greater than 1, VFP concatenates multiple update or delete commands into a single string, separated by semicolons. So you actually only need to act on the cursor, as if it was a buffered DBF file instead of coming from a remote database. First, the UpdateCmd and DeleteCmd properties can contain more than one command. SCX use two tables, Autorefresh.

The following property settings enable VFP to retrieve the new values for Custid and Dateadded after a successful insert:. The complexity is hidden. The problem does exist, and the problem is serious.

We should only take into consideration the following facts: You will hardly want to switch from FoxPro tables to SQL so that your application would lose the ability of working with FoxPro tables and become able to work with SQL databases. Another plus for SQL Server is its reliability especially with indexes. If the target record in the cursor cannot be located in the local or remote table s , it is marked Deleted. So you have decided to switch to SQL Server. For many years we've heard many opinions on Microsoft policy which can sacrifice whole products not the worst ones to the altar of their strategic plans. NET This situation is uncommon, but quite possible. It creates a CursorAdapter and sets the properties needed for RecordRefresh, opens a connection to the database, and fills the cursor. As a result, the CursorAdapter is not aware of changes made by the remote database, and the VFP cursor will not reflect those new values. As a FoxPro programmer, it is difficult to appreciate how much safety and protection is afforded in the Eiffel code shown above. In VFP 8, the CursorAdapter allows you to set WhereType to 4, but does not have the capability to determine which column in the remote table was a timestamp. Once I became aware of another way, I used it. However, VFP has no way to actually display Unicode strings using its native controls. There is a lot more to say, but the rest of it will be quite easy, especially if using the Build buttons on the next tab 2. I did not have to write it although it can be hand generated -- that is completely up to you!

In the first tab 1. If the stumbling block is network productivity, try introducing mandatory buffering with the help of local cursors.

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Tools to quicly adapt a FoxPro application to working with SQL Server