+from moz_sql_parser import parse
+import re
import tables
_connector_type = 'pytables'
h5file = tables.open_file(path)
for table in filter(lambda node: not(isinstance(node, tables.group.Group)), h5file):
- colnames = []
+ colnames = ['value']
if isinstance(table, tables.table.Table):
colnames = table.colnames
'name': table._v_pathname,
'columns': colnames,
'primary_keys': [],
- 'count': table.nrows,
+ 'count': int(table.nrows),
'label_column': None,
'hidden': False,
'fts_table': None,
h5file.close()
return h5tables, views, _connector_type
+
+def _parse_sql(sql, params):
+ # Table name
+ sql = re.sub('(?i)from \[(.*)]', 'from "\g<1>"', sql)
+ # Params
+ for param in params:
+ sql = sql.replace(":" + param, param)
+
+ try:
+ parsed = parse(sql)
+ except:
+ # Propably it's a PyTables expression
+ for token in ['group by', 'order by', 'limit', '']:
+ res = re.search('(?i)where (.*)' + token, sql)
+ if res:
+ modified_sql = re.sub('(?i)where (.*)(' + token + ')', '\g<2>', sql)
+ parsed = parse(modified_sql)
+ parsed['where'] = res.group(1).strip()
+ break
+
+ # Always a list of fields
+ if type(parsed['select']) is not list:
+ parsed['select'] = [parsed['select']]
+
+ return parsed
+
+_operators = {
+ 'eq': '==',
+ 'neq': '!=',
+ 'gt': '>',
+ 'gte': '>=',
+ 'lt': '<',
+ 'lte': '<=',
+ 'and': '&',
+ 'or': '|',
+}
+
+class Connection:
+ def __init__(self, path):
+ self.path = path
+ self.h5file = tables.open_file(path)
+
+ def execute(self, sql, params=None, truncate=False, page_size=None, max_returned_rows=None):
+ if params is None:
+ params = {}
+ rows = []
+ truncated = False
+ description = []
+
+ parsed_sql = _parse_sql(sql, params)
+
+ if parsed_sql['from'] == 'sqlite_master':
+ rows = self._execute_datasette_query(sql, params)
+ description = (('value',))
+ return rows, truncated, description
+
+ table = self.h5file.get_node(parsed_sql['from'])
+ table_rows = []
+ fields = parsed_sql['select']
+ colnames = ['value']
+ if type(table) is tables.table.Table:
+ colnames = table.colnames
+
+ query = ''
+ start = 0
+ end = table.nrows
+
+ # Use 'where' statement or get all the rows
+ def _cast_param(field, pname):
+ # Cast value to the column type
+ coltype = table.dtype.name
+ if type(table) is tables.table.Table:
+ coltype = table.coltypes[field]
+ fcast = None
+ if coltype == 'string':
+ fcast = str
+ elif coltype.startswith('int'):
+ fcast = int
+ elif coltype.startswith('float'):
+ fcast = float
+ if fcast:
+ params[pname] = fcast(params[pname])
+
+ def _translate_where(where):
+ # Translate SQL to PyTables expression
+ nonlocal start, end
+ expr = ''
+ operator = list(where)[0]
+
+ if operator in ['and', 'or']:
+ subexpr = [_translate_where(e) for e in where[operator]]
+ subexpr = filter(lambda e: e, subexpr)
+ subexpr = ["({})".format(e) for e in subexpr]
+ expr = " {} ".format(_operators[operator]).join(subexpr)
+ elif operator == 'exists':
+ pass
+ elif where == {'eq': ['rowid', 'p0']}:
+ start = int(params['p0'])
+ end = start + 1
+ elif where == {'gt': ['rowid', 'p0']}:
+ start = int(params['p0']) + 1
+ else:
+ left, right = where[operator]
+ if left in params:
+ _cast_param(right, left)
+ elif right in params:
+ _cast_param(left, right)
+
+ expr = "{left} {operator} {right}".format(left=left, operator=_operators.get(operator, operator), right=right)
+
+ return expr
+
+ if 'where' in parsed_sql:
+ if type(parsed_sql['where']) is dict:
+ query = _translate_where(parsed_sql['where'])
+ else:
+ query = parsed_sql['where']
+
+ # Sort by column
+ orderby = ''
+ if 'orderby' in parsed_sql:
+ orderby = parsed_sql['orderby']
+ if type(orderby) is list:
+ orderby = orderby[0]
+ orderby = orderby['value']
+ if orderby == 'rowid':
+ orderby = ''
+
+ # Limit number of rows
+ limit = None
+ if 'limit' in parsed_sql:
+ limit = int(parsed_sql['limit'])
+
+ # Truncate if needed
+ if page_size and max_returned_rows and truncate:
+ if max_returned_rows == page_size:
+ max_returned_rows += 1
+
+ # Execute query
+ if query:
+ table_rows = table.where(query, params, start, end)
+ elif orderby:
+ table_rows = table.itersorted(orderby, start=start, stop=end)
+ else:
+ table_rows = table.iterrows(start, end)
+
+ # Prepare rows
+ def normalize_field_value(value):
+ if type(value) is bytes:
+ return value.decode('utf-8')
+ elif not type(value) in (int, float, complex):
+ return str(value)
+ else:
+ return value
+
+ def make_get_rowid():
+ if type(table) is tables.table.Table:
+ def get_rowid(row):
+ return int(row.nrow)
+ else:
+ rowid = start - 1
+ def get_rowid(row):
+ nonlocal rowid
+ rowid += 1
+ return rowid
+ return get_rowid
+
+ def make_get_row_value():
+ if type(table) is tables.table.Table:
+ def get_row_value(row, field):
+ return row[field]
+ else:
+ def get_row_value(row, field):
+ return row
+ return get_row_value
+
+ if len(fields) == 1 and type(fields[0]['value']) is dict and \
+ fields[0]['value'].get('count') == '*':
+ rows.append(Row({'count(*)': int(table.nrows)}))
+ else:
+ get_rowid = make_get_rowid()
+ get_row_value = make_get_row_value()
+ count = 0
+ for table_row in table_rows:
+ count += 1
+ if limit and count > limit:
+ break
+ if truncate and max_returned_rows and count > max_returned_rows:
+ truncated = True
+ break
+ row = Row()
+ for field in fields:
+ field_name = field['value']
+ if type(field_name) is dict and 'distinct' in field_name:
+ field_name = field_name['distinct']
+ if field_name == 'rowid':
+ row['rowid'] = get_rowid(table_row)
+ elif field_name == '*':
+ for col in colnames:
+ row[col] = normalize_field_value(get_row_value(table_row, col))
+ else:
+ row[field_name] = normalize_field_value(get_row_value(table_row, field_name))
+ rows.append(row)
+
+ # Prepare query description
+ for field in [f['value'] for f in fields]:
+ if field == '*':
+ for col in colnames:
+ description.append((col,))
+ else:
+ description.append((field,))
+
+ # Return the rows
+ return rows, truncated, tuple(description)
+
+ def _execute_datasette_query(self, sql, params):
+ "Datasette special queries for getting tables info"
+ if sql == "SELECT count(*) from sqlite_master WHERE type = 'view' and name=:n":
+ row = Row()
+ row['count(*)'] = 0
+ return [row]
+ elif sql == 'select sql from sqlite_master where name = :n and type="table"':
+ try:
+ table = self.h5file.get_node(params['n'])
+ colnames = ['value']
+ if type(table) is tables.table.Table:
+ colnames = table.colnames
+ row = Row()
+ row['sql'] = 'CREATE TABLE {} ({})'.format(params['n'], ", ".join(colnames))
+ return [row]
+ except:
+ return []
+ else:
+ raise Exception("SQLite queries cannot be executed with this connector")
+
+
+class Row(list):
+ def __init__(self, values=None):
+ self.labels = []
+ self.values = []
+ if values:
+ for idx in values:
+ self.__setitem__(idx, values[idx])
+
+ def __setitem__(self, idx, value):
+ if type(idx) is str:
+ if idx in self.labels:
+ self.values[self.labels.index(idx)] = value
+ else:
+ self.labels.append(idx)
+ self.values.append(value)
+ else:
+ self.values[idx] = value
+
+ def __getitem__(self, idx):
+ if type(idx) is str:
+ return self.values[self.labels.index(idx)]
+ else:
+ return self.values[idx]
+
+ def __iter__(self):
+ return self.values.__iter__()
projects / datasette-pytables.git / blobdiff