public GroovyRowResult firstRow(GString gstring) throws SQLException {
        List<Object> params = getParameters(gstring);
        String sql = asSql(gstring, params);
        return firstRow(sql, params);
    }
public GroovyRowResult firstRow ( GString gstring ) throws SQLException { List < Object > params = getParameters ( gstring ) ; String sql = asSql ( gstring , params ) ; return firstRow ( sql , params ) ; }
Performs the given SQL query and return
the first row of the result set.
The query may contain GString expressions.
<p>
Example usage:
<pre>
def location = 25
def ans = sql.firstRow("select * from PERSON where location_id {@code <} $location")
println ans.firstname
</pre>
<p>
Resource handling is performed automatically where appropriate.

@param gstring a GString containing the SQL query with embedded params
@return a GroovyRowResult object or <code>null</code> if no row is found
@throws SQLException if a database access error occurs
@see #expand(Object)