database module

sqlalchemy interface to PySDB database

PySDB database is a simple sqlite3-based relational database to store structural data from the field. You can use apsg to manipulate the data or you can use the GUI application pysdb. There is also the QGIS plugin readsdb to plot data on a map or use map-based select to plot stereonets.

The following snippet demonstrate how to create database programmatically

>>> # Create database
>>> from apsg.database import SDBSession
>>> db = SDBSession('database.sdb', create=True)
>>> # Create unit
>>> unit = db.unit('DMU', description='Deamonic Magmatic Unit')
>>> # Create site
>>> site = db.site('LX001', unit=unit, x_coord=25934.36, y_coord=564122.5, description='diorite dyke')
>>> # Create structural types
>>> S2 = db.structype('S2', description='Solid-state foliation', planar=1)
>>> L2 = db.structype('L2', description='Solid-state lineation', planar=0)
>>> # Add measurement
>>> fol = db.add_structdata(site, S2, 150, 36)
>>> lin = db.add_structdata(site, L2, 83, 16)
>>> # Commit changes
>>> db.commit()
>>> # Close database
>>> db.close()

You can tag individual data

>>> db = SDBSession('database.sdb')
>>> site = db.site('LX001')
>>> struct = db.structype('S2')
>>> tag_plot = db.tag('plot', description='to be plotted')
>>> tag_ap = db.tag('AP', description='axial plane')
>>> fol = db.add_structdata(site, struct, 324, 78, tags=[tag_plot, tag_ap])
>>> db.commit()
>>> db.close()

or you can attach linear and planar features (e.g. fault data)

>>> db = SDBSession('database.sdb')
>>> site = db.site(name='LX001')
>>> S = db.structype(structure='S')
>>> L = db.structype(structure='L')
>>> fol = db.add_structdata(site, S, 220, 28)
>>> lin = db.add_structdata(site, L, 212, 26)
>>> pair = db.attach(fol, lin)
>>> db.commit()
>>> db.close()

You can open existing database and select existing site and type of structure

>>> db = SDBSession('database.sdb')
>>> site = db.site('LX001')
>>> S2 = db.structype('S2')
>>> L2 = db.structype('L2')

and insert Foliation, Lineation or Pair directly

>>> f = fol(196, 39)
>>> l = lin(210, 37)
>>> db.add_fol(site, S2, f)
>>> db.add_lin(site, L2, l)
>>> p = pair(258, 42, 220, 30)
>>> db.add_pair(site, S2, L2, pair)
>>> db.commit()
>>> db.close()

To retrieve data as FeatureSet you can use getset method:

>>> db = SDBSession('database.sdb')
>>> S2 = db.structype('S2')
>>> g = db.getset(S2)

or directly

>>> g = db.getset('S2')