sql(1)

DESCRIPTION
SQL support for GRASS.

Supported is a limited set of SQL functions and operators.

FUNCTIONS
  ALTER TABLE table ADD [COLUMN] columndef
  CREATE TABLE table ( columndefs )
  DROP TABLE table
  SELECT columns FROM table
  SELECT columns FROM table WHERE condition
  DELETE FROM table
  DELETE FROM table WHERE condition
  INSERT INTO table values
  INSERT INTO table ( columns ) values
  UPDATE table SET assignments
  UPDATE table SET assignments WHERE condition

OPERATORS
  "=" : equal
  "<" : smaller than
  "<=" : smaller/equal than
  ">" : larger than
  ">=" : larger/equal than
  "<>" : not equal
  "~" : Substring matching

NOTES

         SQL does not support '.' (dots) in table names.

         Supported table name characters are only:
        [A-Za-z][A-Za-z0-9_]*

         A table name must start with a character, not a number.

         Brackets are needed, e.g. for
              select * from some_table where (3*(some_field - another_field) > 5)
        The parser does not know about precedence yet, so the sub-clause has to be in brackets to avoid ambiguity.

         Text-string matching requires the text part to be 'single quoted' and multiple queries should be contained in "double quotes". e.g.
        d.vect map where="individual='juvenile' and area='beach'"

         An error message such as "dbmi: Protocol error" either indicates an invalid column name or an unsupported column type (then the GRASS SQL parser needs to be extended).

         DBF column names are limited to 10 characters (DBF API definition)

EXAMPLES
Display all vector points except for LAMAR valley and extensive trapping:
 d.vect trapping_sites_points fcol=black icon=basic/diamond col=white size=13 \
    where="valley <> 'LAMAR' OR (valley = 'LAMAR' AND description = 'extensive trapping')"

Select all attributes from table where str1 column values are not 'No Name':
 echo "SELECT * FROM archsites WHERE str1 <> 'No Name'" | db.select

SEE ALSO
db.execute, db.select, db.tables, d.vect
SQL reference links

Last changed: $Date: 2005/05/10 09:58:07 $
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