How to create view in GeoServer?
Creating a SQL View The query can be any SQL statement that is valid as a subquery in a FROM clause (that is, select * from () [as] vtable ). This is the case for most SQL statements, but in some databases special syntax may be needed to call stored procedures.
Can a SQL View take a parameter?
Views provide an abstraction layer to underlying data, simplifying data access. You cannot pass parameters to SQL Server views. Cannot use an Order By clause with views without specifying FOR XML or TOP. Views cannot be created on Temporary Tables.
What is parametric view?
A parametric view lets you define one or more filtering parameters at request time. Building a parametric view is not different from a standard SQL view.
How are SQL views defined in GeoServer 2?
Starting with GeoServer 2.1.0, layers can also be defined as SQL Views. SQL Views allow executing a custom SQL query on each request to the layer. This avoids the need to create a database view for complex queries. Even more usefully, SQL View queries can be parameterized via string substitution.
How are view parameters specified in SQL Server?
The SQL view parameters are specified by adding the viewparams parameter to the WMS GetMap or the WFS GetFeature request. The viewparams argument is a list of key:value pairs, separated by semicolons: viewparams=p1:v1;p2:v2;…
How to parameterize a parametric SQL query in WFS?
Parameterizing SQL Views¶. A parametric SQL view is based on a SQL query containing named parameters. The values for the parameters can be provided dynamically in WMS and WFS requests using the viewparams request parameter. Parameters can have default values specified, to handle the situation where they are not supplied in a request.
How are parameter values supplied in SQL query?
Even more usefully, SQL View queries can be parameterized via string substitution. Parameter values can be supplied in both WMS and WFS requests. Default values can be supplied for parameters, and input values can be validated by Regular Expressions to eliminate the risk of SQL injection attacks.