Querylayer

Querylayer(Query layer) is a layer or independent table defined by SQL query. PassQuerylayerSpatial and non-spatial information can be stored in DBMS, so that the information can be easily integrated into various GIS projects in ArcMap. BecauseQuerylayerThe database tables and views are directly queried through SQL. Therefore, the space used by the Querylayer does not need to be stored in the geographical database.

When performing operations in ArcMap, you can create an instance by defining an SQL query.Querylayer. Then, run the query for the tables and views in the database, and add the result set to ArcMap in the form of layers or independent tables (depending on the query itself.

This query is executed every time this layer is displayed or used in ArcMap. In this way, the latest information can be displayed without generating copies or snapshots of data, which is especially suitable for handling frequently changed dynamic information.QuerylayerThis function is applicable to all DBMS supported by ArcGIS.

QuerylayerAllows ArcMap to integrate data in a geographical database and DBMS. Therefore, regardless of the location and method of information storage,QuerylayerBoth spatial information and non-spatial information can be quickly integrated into GIS projects.

• By defining queries on the tables and views in the DBMS, ArcMap users canQuerylayer"Add to map.
• QuerylayerSimilar to any other element layer or individual table, these layers can be used to display data as input to a geographical processing tool, or accessed programmatically using a developer API.
• CreateQuerylayerIt can be saved as a layer file (. lyr) or used to create a layer package (. lpk ). This makes it easy to share with other applications, map documents, and other users."Querylayer".

Querylayer