SQL Expression

For more, see Information Tools

To activate: Toolbar

Query the current layer. A simple query is built in the SQL Expression dialog. Expressions are kept for the duration of a GeoSync session.  Use SQL expression in conjunction with a geographic search. Additionally, create custom expressions which query multiple fields on the same layer..

To use:

1. Make desired layer current.

2. Activate SQL Statement tool.

Create a simple expression:

1. Choose Field to query.

2. Choose Operator.

3. Enter a Value.

4. Select Add to create the expression.

Note: Click on the down arrow on the right side of the Current Expression text box to access expressions used previously. These expressions are lost when GeoSync is closed.    For often used expressions, setup a Quick Search or copy and paste an expression from a text document.

To execute expression:

After creating a simple expression (see above) there are two ways to use the expression:

• While leaving the SQL Expression dialog open, activate Select Expression from the Toolbar. This searches the entire layer.

or

• Use a Selection Tool or Buffer to select an area to query.

To create a custom/complex expression:

In the Current Expression field: enter the field name, Operator, search value (in single quotes), space, AND, space, and then repeat for each field to be queried. (an SQL query is Case Sensitive)

An example using a Roads layer: LENGTH > 1000 AND OWNERSHIP = 'CITY'

Also, OR may be used as a conjunction to make a search more inclusive. For example to search for Roads owned by the City and County, an expression would appear as follows: OWNERSHIP = 'CITY' OR OWNERSHIP = 'COUNTY'  

Hint: Build a simple expression and modify to create a custom expression.