SQL 查询可用于根据属性值的组合来选择要素。例如,如果只想查找具有波动潮汐情况的河流,则可定义 SQL 查询来查找这些要素。 “SQL 查询校验”也可用于按批处理方式对数据库运行预定义的 WHERE 子句。系统将返回参数与 SQL 查询中定义的参数相符的所有要素或行。
The string shown in the SQL query may only slightly resemble the value shown in the table, especially when time is involved. For instance, a time entered as 00:00:15 will show as 12:00:15 a.m. in the attribute table, with the United States as your regional settings, and the comparab...
借助查询构建器,您可以通过输入 SQL 语法在本地创建查询,也可以通过选择组件以交互方式创建查询。 编写 SQL 语法除可让您访问所有 SQL 功能之外,是更高级的选项。 以交互方式构建查询 在查询构建器的默认模式下,您可以构建查询,方法是:从根据所选字段类型填充和预过滤的下拉菜单中进行选择。 此模式下的工作优势...
--SQL Server and PostgreSQL querySELECTrelationships.type,origin_items.nameAS"Origin Name",dest_items.nameAS"Dest Name"FROMgdb_itemsASorigin_items,gdb_itemrelationshipsASrelationships,gdb_itemsASdest_itemsWHEREorigin_items.UUID=relationships.originidANDdest_items.UUID=relationships.destid;--Oracle query...
current map scale. The default value of zero is passed in when you use this parameter. There are no other properties to set. You can specify this parameter as many times as necessary in your SQL query. The following examples use theview_scaleparameter inSQL ServerandPostgreSQLdatabase ...
(); }// Prepare a SQL query with error handlingfunctiondb_prepare_sql(db, sql) { let dbQuery =db.query();dbQuery.prepare(sql);if(dbQuery.error)throw_db_error(dbQuery.error);returndbQuery; }// Execute prepared SQL query with logging and error handlingfunctiondb_exec_prepared(dbQuery, .....
Click SQL Query to open the Label Class pane. In the Label Class pane, click + New expression. Toggle SQL on. Specify the following expression in the SQL expression text box. Replace <field_name> with the name of the field containing the contour elevation value, and <Interval> ...
Learn how to execute a SQL query to return features from a feature layer based on spatial and attribute criteria.A feature layer can contain a large number of features stored in ArcGIS. You can query a layer to access a subset of its features using any combination of spatial and attribute ...
If the input is a feature service, the default expression type isSQL. For any other type of input, the default expression type isPython. To learn more aboutPythonexpressions, seeCalculate FieldPythonexamples. To learn more aboutArcadeexpressions, seeArcGIS Arcadein the Developer help. ...
在关系型数据库中,查询条件是通过SQL语句的Where子语句来完成的。在ArcGIS Engine中不能直接使用SQL语句,但ArcGIS Engine提供了QueryFilter和SpatialFilter两个过滤器对象来配合完成查询条件的设置,从而查询到想要的数据。 QueryFilter过滤器主要用于对属性数据查询条件的设置,它主要实现IQueryFilter接口从而实现属性查询功能...