dbSQL Tools README   GRASS Reference Manual   dbSQL Tools README




     INTRODUCTION

     The dbSQL tools provide a command line interface between the
     GRASS GIS and INFORMIX relational database products. These
     tools have been developed by the University of Arkansas,
     Center for Advanced Spatial Technologies (CAST), under
     contract to the SCS NCGIS.

     The dbSQL tools consist of 13 seperate command line tools
     which can be used in conjunction with the GRASS GIS (V4.0)
     and the INFORMIX standard engine (SE), SQL database
     products. Use of these tools requires a basic familiarity
     with SQL syntax and the 4.0 version of GRASS.

     Three realtional databases are included with the GRASS 4.1
     release, along with a corresponding GRASS location (SECO).
     These databases contain data for 4 counties in Texas within
     the SECO Creek drainage. The databases included here have
     been developed by the SCS, National Cartography and GIS
     Center at Fort Worth and CAST.

     A detailed description of the sample databases is provided
     in the README file in the directory SECO_DB. This
     description includes annotated database schemas for the
     relational files and a complete list of the raster, vector
     and pointfiles which are distributed with the spatial data.
     The sample relational databases are not built and populated
     as part of the standard GRASS compilation. Users who wish to
     build these sample daatbases should consult the specific
     instructions in the README file in the directory SECO_DB.

     GRASS manual pages are available for each of the toools.
     These manual pages can be accessed by using the g.manual
     GRASS command.  The manual pages include examples which have
     been developed using the sample databases, both spatial and
     relational. The user is encouraged to become familiar with
     these examples prior to developing ad hoc applications using
     the dbSQL tools.

     Relational databases and corresponding GRASS data are being
     provided because of the data requirements needed to
     effectively use these tools.  In order to use the spatial
     data in GRASS in conjunction with the attribute data in a
     relational database some form of linkage must be established
     between the two sets of data. In most instances this linkage
     will be between a column in the database and either the
     GRASS category values (raster data), or the dig_att values
     (vector data), or the locational data which can be obtained
     from a raster surface using the mouse (point data). Because
     few, if any current GRASS users, will have spatial and
     realtional databases which conform to these requirements and



GRASS                    U.S. Army CERL                         1






dbSQL Tools README   GRASS Reference Manual   dbSQL Tools README



     because of the effort requred to retrofit these types of
     linkages after the fact it was decided that the current
     release should include a "pre-linked" set of spatial and
     attribute data.





     COMPILATION

     To compile the the GRASS-Informix RDBMS interface run
     gmake4.0 from the src.garden directory in the GRASS source
     code. The resulting binaries will be placed in the
     $GISBASE/garden/bin directory.  To run these tools the
     Informix database engine software and the ISQL software must
     be accessible to the user. In addition, the environment
     variables needed by Informix must be set (eg. INFORMIXDIR
     and DBPATH). For additional discussion concerning these
     variables see the Informix SQL Reference Manual or consult
     your Systems Administrator.


































GRASS                    U.S. Army CERL                         2