KB-30971: Changing database type.
Question: If an application starts with an Access database and in the middle of the process it migrates to SQL/Oracle, will the previous data be sent to the new database?…
Utilizando grupos de tags OPC.
Descrição: Em uma aplicação projetada para comunicar com 1500 tags OPC, qual a melhor opção de arquitetura para o cliente OPC: múltiplos grupos OPC com um reduzido número de tags…
Using OPC tag groups.
Question: In an application designed to communicate with 1500 OPC tags, which of the following is the best option for the OPC client: several OPC groups with fewer tags (for…
KB-31698: Number of SQL clients required in an E3 application.
Question: How many SQL client licenses are required in an application with two E3Servers (in Hot-Standby) and five Viewers? Solution: The communication between E3 and the database happens exclusively in…
KB-26755: Access database and application performance.
Question: My application’s got slower after two weeks working with an Access database. Why has this happened, and how can I fix it? Solution: This may have happened because the…
Structure Query Language (SQL): Chapter 7 – Views.
A view is an alternative solution for observing data from one or more of the tables comprising a database. You can regard it as a virtual table or a stored…
Structure Query Language (SQL): Chapter 8 – Triggers.
Triggers are a type of special stored procedures that are executed whenever there is an attempt to change the data in a table protected by them. DML triggers (Data Manipulation…
Structure Query Language (SQL): Chapter 9 – Stored Procedures.
A stored procedure is a set of instructions developed in T-SQL language (Transact-Sql) that, whenever stored or saved, are inside the server in a pre-compiled way. This procedure is stored…
Connecting Elipse SCADA to an OpenOffice Calc spreadsheet.
OpenOffice can establish a DDE connection, where you can read data via Elipse SCADA. According to the software’s documentation, to do so you will need to insert the following paramenters:…
Structure Query Language (SQL): Chapter 6 – SQL Commands.
This article illustrates a few SQL commands. To illustrate how they are used, the following tables will work as reference: Store_Information table: Store_Name Sales Date_Time Los Angeles 1500 05-Jan-1999…