scripts/extract_sqlite_models.py, thanks Michele

2012-10-31 10:23:56 -05:00
parent 863140fec9
commit 15e5b1a2f0
2 changed files with 115 additions and 1 deletions
@@ -0,0 +1,114 @@
+#!/usr/bin/python
+# -*- coding: utf-8 -*-
+
+'''
+Create the web2py model code needed to access your sqlite legacy db.
+
+Usage:
+python extract_sqlite_models.py
+
+Access your tables with:
+legacy_db(legacy_db.mytable.id>0).select()
+
+
+extract_sqlite_models.py -- Copyright (C) Michele Comitini
+This code is distributed with web2py.
+
+The regexp code and the dictionary type map was extended from
+extact_mysql_models.py that comes with web2py. extact_mysql_models.py is Copyright (C) Falko Krause.
+
+'''
+import re
+import sys
+import sqlite3
+
+data_type_map = dict(
+    varchar='string',
+    int='integer',
+    integer='integer',
+    tinyint='integer',
+    smallint='integer',
+    mediumint='integer',
+    bigint='integer',
+    float='double',
+    double='double',
+    char='string',
+    decimal='integer',
+    date='date',
+    time='time',
+    timestamp='datetime',
+    datetime='datetime',
+    binary='blob',
+    blob='blob',
+    tinyblob='blob',
+    mediumblob='blob',
+    longblob='blob',
+    text='text',
+    tinytext='text',
+    mediumtext='text',
+    longtext='text',
+    bit='boolean',
+    nvarchar='text',
+    numeric='decimal(30,15)',
+    real='decimal(30,15)',
+)
+
+def get_foreign_keys(sql_lines):
+    fks = dict()
+    for line in sql_lines[1:-1]:
+        hit = re.search(r'FOREIGN\s+KEY\s+\("(\S+)"\)\s+REFERENCES\s+"(\S+)"\s+\("(\S+)"\)', line)
+        if hit:
+            fks[hit.group(1)] =  hit.groups()[1:]
+
+    return fks
+
+def sqlite(database_name):
+    conn = sqlite3.connect(database_name)
+    c = conn.cursor()
+    r = c.execute(r"select name,sql from sqlite_master where type='table' and not name like '\_%' and not lower(name) like 'sqlite_%'")
+    tables = r.fetchall()
+    connection_string = "legacy_db = DAL('sqlite://%s')" % database_name.split('/')[-1]
+    legacy_db_table_web2py_code = []
+    for table_name, sql_create_stmnt in tables:
+        if table_name.startswith('_'):
+            continue
+        if 'CREATE' in sql_create_stmnt:  # check if the table exists
+            #remove garbage lines from sql statement
+            sql_lines = sql_create_stmnt.split('\n')
+            sql_lines = [x for x in sql_lines if not(
+                x.startswith('--') or x.startswith('/*') or x == '')]
+            #generate the web2py code from the create statement
+            web2py_table_code = ''
+            fields = []
+            fks = get_foreign_keys(sql_lines)
+            for line in sql_lines[1:-1]:
+                if re.search('KEY', line) or re.search('PRIMARY', line) or re.search('"ID"', line) or line.startswith(')'):
+                    continue
+                hit = re.search(r'"(\S+)"\s+(\w+(\(\S+\))?),?( .*)?', line)
+                if hit is not None:
+                    name, d_type = hit.group(1), hit.group(2)
+                    d_type = re.sub(r'(\w+)\(.*', r'\1', d_type)
+                    name = unicode(re.sub('`', '', name))
+                    if name in fks.keys():
+                        if fks[name][1].lower() == 'id':
+                            field_type = 'reference %s' % (fks[name][0])
+                        else:
+                            field_type = 'reference %s.%s' % (fks[name][0], fks[name][1])
+                    else:
+                        field_type = data_type_map[d_type]
+                    web2py_table_code += "\n    Field('%s','%s')," % (
+                        name, field_type)
+            web2py_table_code = "legacy_db.define_table('%s',%s\n    migrate=False)" % (table_name, web2py_table_code)
+            legacy_db_table_web2py_code.append(web2py_table_code)
+    #----------------------------------------
+    #write the legacy db to file
+    legacy_db_web2py_code = connection_string + "\n\n"
+    legacy_db_web2py_code += "\n\n#--------\n".join(
+        legacy_db_table_web2py_code)
+    return legacy_db_web2py_code
+
+if len(sys.argv) < 2:
+    print 'USAGE:\n\n    extract_mysql_models.py data_basename\n\n'
+else:
+    print "# -*- coding: utf-8 -*-"
+    print sqlite(sys.argv[1])