Reports & Queries - Source : www.pcsoft-windev-webdev.com

2. HOW DO I CREATE A QUERY?2.1 OverviewTo create a query, the query editor proposes two methods:• create the query via a wizard or a description window with automatic generation of the SQL code.• enter the SQL code. See “Query in SQL code”, page 177 for more details.The query editor allows you to create several types of queries:• Select query: Used to view a selection of records coming from a database. See “Select query”,page 167 for more details.• Insert query: Used to add records into a database file. See “Insert query”, page 169 for more details.ImportantReports & Queries cannot be used to create Insert queries.• Update query: Used to modify records in a database file. See “Update query”, page171 for moredetails.ImportantReports & Queries cannot be used to create Update queries.• Delete query: Used to delete records from a database file. See “Delete query”, page 174 for moredetails.ImportantReports & Queries cannot be used to create Delete queries.• Union query: Used to combine selection queries. See “Union query”, page 175 for more details.Note: All types of queries can be based on items belonging to:• a data file described in the analysis.• a query that was created beforehand.Insert, Update and Delete queries:The ability to create Insert, Update and Delete queries is supported for compatibility with the SQL standard.The use of native WLanguage commands (HReadFirst, HReadNext, HAdd, HModify, HDelete, …) is muchmore suitable for programming this type of process.SQL is a query language used to interrogate data but it is not well suited for custom modifications of thisdata. To add, modify or delete records in a database file, the performance and the simplicity of WinDev andWebDev are unmatchable.166Part 2: Query editor