from .utils import sqlite3, OperationalError, suggest_column_types, column_affinity from collections import namedtuple, OrderedDict from collections.abc import Mapping import contextlib import datetime import decimal import hashlib import inspect import itertools import json import os import pathlib import re import sys import textwrap import uuid SQLITE_MAX_VARS = 999 _virtual_table_using_re = re.compile( r""" ^ # Start of string \s*CREATE\s+VIRTUAL\s+TABLE\s+ # CREATE VIRTUAL TABLE ( '(?P[^']*(?:''[^']*)*)' | # single quoted name "(?P[^"]*(?:""[^"]*)*)" | # double quoted name `(?P[^`]+)` | # `backtick` quoted name \[(?P[^\]]+)\] | # [...] quoted name (?P # SQLite non-quoted identifier [A-Za-z_\u0080-\uffff] # \u0080-\uffff = "any character larger than u007f" [A-Za-z_\u0080-\uffff0-9\$]* # zero-or-more alphanemuric or $ ) ) \s+(IF\s+NOT\s+EXISTS\s+)? # IF NOT EXISTS (optional) USING\s+(?P\w+) # e.g. USING FTS5 """, re.VERBOSE | re.IGNORECASE, ) try: import pandas as pd except ImportError: pd = None try: import numpy as np except ImportError: np = None Column = namedtuple( "Column", ("cid", "name", "type", "notnull", "default_value", "is_pk") ) ForeignKey = namedtuple( "ForeignKey", ("table", "column", "other_table", "other_column") ) Index = namedtuple("Index", ("seq", "name", "unique", "origin", "partial", "columns")) Trigger = namedtuple("Trigger", ("name", "table", "sql")) DEFAULT = object() COLUMN_TYPE_MAPPING = { float: "FLOAT", int: "INTEGER", bool: "INTEGER", str: "TEXT", bytes.__class__: "BLOB", bytes: "BLOB", memoryview: "BLOB", datetime.datetime: "TEXT", datetime.date: "TEXT", datetime.time: "TEXT", decimal.Decimal: "FLOAT", None.__class__: "TEXT", uuid.UUID: "TEXT", # SQLite explicit types "TEXT": "TEXT", "INTEGER": "INTEGER", "FLOAT": "FLOAT", "BLOB": "BLOB", "text": "TEXT", "integer": "INTEGER", "float": "FLOAT", "blob": "BLOB", } # If numpy is available, add more types if np: COLUMN_TYPE_MAPPING.update( { np.int8: "INTEGER", np.int16: "INTEGER", np.int32: "INTEGER", np.int64: "INTEGER", np.uint8: "INTEGER", np.uint16: "INTEGER", np.uint32: "INTEGER", np.uint64: "INTEGER", np.float16: "FLOAT", np.float32: "FLOAT", np.float64: "FLOAT", } ) # If pandas is available, add more types if pd: COLUMN_TYPE_MAPPING.update({pd.Timestamp: "TEXT"}) class AlterError(Exception): pass class NoObviousTable(Exception): pass class BadPrimaryKey(Exception): pass class NotFoundError(Exception): pass class PrimaryKeyRequired(Exception): pass class InvalidColumns(Exception): pass class Database: def __init__( self, filename_or_conn=None, memory=False, recreate=False, recursive_triggers=True, tracer=None, ): assert (filename_or_conn is not None and not memory) or ( filename_or_conn is None and memory ), "Either specify a filename_or_conn or pass memory=True" if memory or filename_or_conn == ":memory:": self.conn = sqlite3.connect(":memory:") elif isinstance(filename_or_conn, (str, pathlib.Path)): if recreate and os.path.exists(filename_or_conn): os.remove(filename_or_conn) self.conn = sqlite3.connect(str(filename_or_conn)) else: assert not recreate, "recreate cannot be used with connections, only paths" self.conn = filename_or_conn self._tracer = tracer if recursive_triggers: self.execute("PRAGMA recursive_triggers=on;") @contextlib.contextmanager def tracer(self, tracer=None): prev_tracer = self._tracer self._tracer = tracer or print try: yield self finally: self._tracer = prev_tracer def __getitem__(self, table_name): return self.table(table_name) def __repr__(self): return "".format(self.conn) def register_function(self, fn=None, deterministic=None): def register(fn): name = fn.__name__ arity = len(inspect.signature(fn).parameters) kwargs = {} if deterministic and sys.version_info >= (3, 8): kwargs["deterministic"] = True self.conn.create_function(name, arity, fn, **kwargs) return fn if fn is None: return register else: register(fn) def execute(self, sql, parameters=None): if self._tracer: self._tracer(sql, parameters) if parameters is not None: return self.conn.execute(sql, parameters) else: return self.conn.execute(sql) def executescript(self, sql): if self._tracer: self._tracer(sql, None) return self.conn.executescript(sql) def table(self, table_name, **kwargs): klass = View if table_name in self.view_names() else Table return klass(self, table_name, **kwargs) def escape(self, value): # Normally we would use .execute(sql, [params]) for escaping, but # occasionally that isn't available - most notable when we need # to include a "... DEFAULT 'value'" in a column definition. return self.execute( # Use SQLite itself to correctly escape this string: "SELECT quote(:value)", {"value": value}, ).fetchone()[0] def table_names(self, fts4=False, fts5=False): where = ["type = 'table'"] if fts4: where.append("sql like '%USING FTS4%'") if fts5: where.append("sql like '%USING FTS5%'") sql = "select name from sqlite_master where {}".format(" AND ".join(where)) return [r[0] for r in self.execute(sql).fetchall()] def view_names(self): return [ r[0] for r in self.execute( "select name from sqlite_master where type = 'view'" ).fetchall() ] @property def tables(self): return [self[name] for name in self.table_names()] @property def views(self): return [self[name] for name in self.view_names()] @property def triggers(self): return [ Trigger(*r) for r in self.execute( "select name, tbl_name, sql from sqlite_master where type = 'trigger'" ).fetchall() ] @property def journal_mode(self): return self.execute("PRAGMA journal_mode;").fetchone()[0] def enable_wal(self): if self.journal_mode != "wal": self.execute("PRAGMA journal_mode=wal;") def disable_wal(self): if self.journal_mode != "delete": self.execute("PRAGMA journal_mode=delete;") def execute_returning_dicts(self, sql, params=None): cursor = self.execute(sql, params or tuple()) keys = [d[0] for d in cursor.description] return [dict(zip(keys, row)) for row in cursor.fetchall()] def resolve_foreign_keys(self, name, foreign_keys): # foreign_keys may be a list of strcolumn names, a list of ForeignKey tuples, # a list of tuple-pairs or a list of tuple-triples. We want to turn # it into a list of ForeignKey tuples if all(isinstance(fk, ForeignKey) for fk in foreign_keys): return foreign_keys if all(isinstance(fk, str) for fk in foreign_keys): # It's a list of columns fks = [] for column in foreign_keys: other_table = self[name].guess_foreign_table(column) other_column = self[name].guess_foreign_column(other_table) fks.append(ForeignKey(name, column, other_table, other_column)) return fks assert all( isinstance(fk, (tuple, list)) for fk in foreign_keys ), "foreign_keys= should be a list of tuples" fks = [] for tuple_or_list in foreign_keys: assert len(tuple_or_list) in ( 2, 3, ), "foreign_keys= should be a list of tuple pairs or triples" if len(tuple_or_list) == 3: fks.append( ForeignKey( name, tuple_or_list[0], tuple_or_list[1], tuple_or_list[2] ) ) else: # Guess the primary key fks.append( ForeignKey( name, tuple_or_list[0], tuple_or_list[1], self[name].guess_foreign_column(tuple_or_list[1]), ) ) return fks def create_table_sql( self, name, columns, pk=None, foreign_keys=None, column_order=None, not_null=None, defaults=None, hash_id=None, extracts=None, ): foreign_keys = self.resolve_foreign_keys(name, foreign_keys or []) foreign_keys_by_column = {fk.column: fk for fk in foreign_keys} # any extracts will be treated as integer columns with a foreign key extracts = resolve_extracts(extracts) for extract_column, extract_table in extracts.items(): if isinstance(extract_column, tuple): assert False # Ensure other table exists if not self[extract_table].exists(): self.create_table(extract_table, {"id": int, "value": str}, pk="id") columns[extract_column] = int foreign_keys_by_column[extract_column] = ForeignKey( name, extract_column, extract_table, "id" ) # Soundness check not_null, and defaults if provided not_null = not_null or set() defaults = defaults or {} assert all( n in columns for n in not_null ), "not_null set {} includes items not in columns {}".format( repr(not_null), repr(set(columns.keys())) ) assert all( n in columns for n in defaults ), "defaults set {} includes items not in columns {}".format( repr(set(defaults)), repr(set(columns.keys())) ) validate_column_names(columns.keys()) column_items = list(columns.items()) if column_order is not None: column_items.sort( key=lambda p: column_order.index(p[0]) if p[0] in column_order else 999 ) if hash_id: column_items.insert(0, (hash_id, str)) pk = hash_id # Soundness check foreign_keys point to existing tables for fk in foreign_keys: if not any( c for c in self[fk.other_table].columns if c.name == fk.other_column ): raise AlterError( "No such column: {}.{}".format(fk.other_table, fk.other_column) ) column_defs = [] # ensure pk is a tuple single_pk = None if isinstance(pk, list) and len(pk) == 1 and isinstance(pk[0], str): pk = pk[0] if isinstance(pk, str): single_pk = pk if pk not in [c[0] for c in column_items]: column_items.insert(0, (pk, int)) for column_name, column_type in column_items: column_extras = [] if column_name == single_pk: column_extras.append("PRIMARY KEY") if column_name in not_null: column_extras.append("NOT NULL") if column_name in defaults and defaults[column_name] is not None: column_extras.append( "DEFAULT {}".format(self.escape(defaults[column_name])) ) if column_name in foreign_keys_by_column: column_extras.append( "REFERENCES [{other_table}]([{other_column}])".format( other_table=foreign_keys_by_column[column_name].other_table, other_column=foreign_keys_by_column[column_name].other_column, ) ) column_defs.append( " [{column_name}] {column_type}{column_extras}".format( column_name=column_name, column_type=COLUMN_TYPE_MAPPING[column_type], column_extras=(" " + " ".join(column_extras)) if column_extras else "", ) ) extra_pk = "" if single_pk is None and pk and len(pk) > 1: extra_pk = ",\n PRIMARY KEY ({pks})".format( pks=", ".join(["[{}]".format(p) for p in pk]) ) columns_sql = ",\n".join(column_defs) sql = """CREATE TABLE [{table}] ( {columns_sql}{extra_pk} ); """.format( table=name, columns_sql=columns_sql, extra_pk=extra_pk ) return sql def create_table( self, name, columns, pk=None, foreign_keys=None, column_order=None, not_null=None, defaults=None, hash_id=None, extracts=None, ): sql = self.create_table_sql( name=name, columns=columns, pk=pk, foreign_keys=foreign_keys, column_order=column_order, not_null=not_null, defaults=defaults, hash_id=hash_id, extracts=extracts, ) self.execute(sql) return self.table( name, pk=pk, foreign_keys=foreign_keys, column_order=column_order, not_null=not_null, defaults=defaults, hash_id=hash_id, ) def create_view(self, name, sql, ignore=False, replace=False): assert not ( ignore and replace ), "Use one or the other of ignore/replace, not both" create_sql = "CREATE VIEW {name} AS {sql}".format(name=name, sql=sql) if ignore or replace: # Does view exist already? if name in self.view_names(): if ignore: return self elif replace: # If SQL is the same, do nothing if create_sql == self[name].schema: return self self[name].drop() self.execute(create_sql) return self def m2m_table_candidates(self, table, other_table): "Returns potential m2m tables for arguments, based on FKs" candidates = [] tables = {table, other_table} for table in self.tables: # Does it have foreign keys to both table and other_table? has_fks_to = {fk.other_table for fk in table.foreign_keys} if has_fks_to.issuperset(tables): candidates.append(table.name) return candidates def add_foreign_keys(self, foreign_keys): # foreign_keys is a list of explicit 4-tuples assert all( len(fk) == 4 and isinstance(fk, (list, tuple)) for fk in foreign_keys ), "foreign_keys must be a list of 4-tuples, (table, column, other_table, other_column)" foreign_keys_to_create = [] # Verify that all tables and columns exist for table, column, other_table, other_column in foreign_keys: if not self[table].exists(): raise AlterError("No such table: {}".format(table)) if column not in self[table].columns_dict: raise AlterError("No such column: {} in {}".format(column, table)) if not self[other_table].exists(): raise AlterError("No such other_table: {}".format(other_table)) if ( other_column != "rowid" and other_column not in self[other_table].columns_dict ): raise AlterError( "No such other_column: {} in {}".format(other_column, other_table) ) # We will silently skip foreign keys that exist already if not any( fk for fk in self[table].foreign_keys if fk.column == column and fk.other_table == other_table and fk.other_column == other_column ): foreign_keys_to_create.append( (table, column, other_table, other_column) ) # Construct SQL for use with "UPDATE sqlite_master SET sql = ? WHERE name = ?" table_sql = {} for table, column, other_table, other_column in foreign_keys_to_create: old_sql = table_sql.get(table, self[table].schema) extra_sql = ",\n FOREIGN KEY({column}) REFERENCES {other_table}({other_column})\n".format( column=column, other_table=other_table, other_column=other_column ) # Stick that bit in at the very end just before the closing ')' last_paren = old_sql.rindex(")") new_sql = old_sql[:last_paren].strip() + extra_sql + old_sql[last_paren:] table_sql[table] = new_sql # And execute it all within a single transaction with self.conn: cursor = self.conn.cursor() schema_version = cursor.execute("PRAGMA schema_version").fetchone()[0] cursor.execute("PRAGMA writable_schema = 1") for table_name, new_sql in table_sql.items(): cursor.execute( "UPDATE sqlite_master SET sql = ? WHERE name = ?", (new_sql, table_name), ) cursor.execute("PRAGMA schema_version = %d" % (schema_version + 1)) cursor.execute("PRAGMA writable_schema = 0") # Have to VACUUM outside the transaction to ensure .foreign_keys property # can see the newly created foreign key. self.vacuum() def index_foreign_keys(self): for table_name in self.table_names(): table = self[table_name] existing_indexes = { i.columns[0] for i in table.indexes if len(i.columns) == 1 } for fk in table.foreign_keys: if fk.column not in existing_indexes: table.create_index([fk.column]) def vacuum(self): self.execute("VACUUM;") class Queryable: def exists(self): return False def __init__(self, db, name): self.db = db self.name = name @property def count(self): return self.db.execute( "select count(*) from [{}]".format(self.name) ).fetchone()[0] @property def rows(self): return self.rows_where() def rows_where(self, where=None, where_args=None, order_by=None, select="*"): if not self.exists(): return [] sql = "select {} from [{}]".format(select, self.name) if where is not None: sql += " where " + where if order_by is not None: sql += " order by " + order_by cursor = self.db.execute(sql, where_args or []) columns = [c[0] for c in cursor.description] for row in cursor: yield dict(zip(columns, row)) @property def columns(self): if not self.exists(): return [] rows = self.db.execute("PRAGMA table_info([{}])".format(self.name)).fetchall() return [Column(*row) for row in rows] @property def columns_dict(self): "Returns {column: python-type} dictionary" return {column.name: column_affinity(column.type) for column in self.columns} @property def schema(self): return self.db.execute( "select sql from sqlite_master where name = ?", (self.name,) ).fetchone()[0] class Table(Queryable): last_rowid = None last_pk = None def __init__( self, db, name, pk=None, foreign_keys=None, column_order=None, not_null=None, defaults=None, batch_size=100, hash_id=None, alter=False, ignore=False, replace=False, extracts=None, conversions=None, columns=None, ): super().__init__(db, name) self._defaults = dict( pk=pk, foreign_keys=foreign_keys, column_order=column_order, not_null=not_null, defaults=defaults, batch_size=batch_size, hash_id=hash_id, alter=alter, ignore=ignore, replace=replace, extracts=extracts, conversions=conversions or {}, columns=columns, ) def __repr__(self): return "".format( self.name, " (does not exist yet)" if not self.exists() else " ({})".format(", ".join(c.name for c in self.columns)), ) def exists(self): return self.name in self.db.table_names() @property def pks(self): names = [column.name for column in self.columns if column.is_pk] if not names: names = ["rowid"] return names def get(self, pk_values): if not isinstance(pk_values, (list, tuple)): pk_values = [pk_values] pks = self.pks last_pk = pk_values[0] if len(pks) == 1 else pk_values if len(pks) != len(pk_values): raise NotFoundError( "Need {} primary key value{}".format( len(pks), "" if len(pks) == 1 else "s" ) ) wheres = ["[{}] = ?".format(pk_name) for pk_name in pks] rows = self.rows_where(" and ".join(wheres), pk_values) try: row = list(rows)[0] self.last_pk = last_pk return row except IndexError: raise NotFoundError @property def foreign_keys(self): fks = [] for row in self.db.execute( "PRAGMA foreign_key_list([{}])".format(self.name) ).fetchall(): if row is not None: id, seq, table_name, from_, to_, on_update, on_delete, match = row fks.append( ForeignKey( table=self.name, column=from_, other_table=table_name, other_column=to_, ) ) return fks @property def virtual_table_using(self): "Returns type of virtual table or None if this is not a virtual table" match = _virtual_table_using_re.match(self.schema) if match is None: return None return match.groupdict()["using"].upper() @property def indexes(self): sql = 'PRAGMA index_list("{}")'.format(self.name) indexes = [] for row in self.db.execute_returning_dicts(sql): index_name = row["name"] index_name_quoted = ( '"{}"'.format(index_name) if not index_name.startswith('"') else index_name ) column_sql = "PRAGMA index_info({})".format(index_name_quoted) columns = [] for seqno, cid, name in self.db.execute(column_sql).fetchall(): columns.append(name) row["columns"] = columns # These columns may be missing on older SQLite versions: for key, default in {"origin": "c", "partial": 0}.items(): if key not in row: row[key] = default indexes.append(Index(**row)) return indexes @property def triggers(self): return [ Trigger(*r) for r in self.db.execute( "select name, tbl_name, sql from sqlite_master where type = 'trigger'" " and tbl_name = ?", (self.name,), ).fetchall() ] def create( self, columns, pk=None, foreign_keys=None, column_order=None, not_null=None, defaults=None, hash_id=None, extracts=None, ): columns = {name: value for (name, value) in columns.items()} with self.db.conn: self.db.create_table( self.name, columns, pk=pk, foreign_keys=foreign_keys, column_order=column_order, not_null=not_null, defaults=defaults, hash_id=hash_id, extracts=extracts, ) return self def transform( self, *, types=None, rename=None, drop=None, pk=DEFAULT, not_null=None, defaults=None, drop_foreign_keys=None, column_order=None, ): assert self.exists(), "Cannot transform a table that doesn't exist yet" sqls = self.transform_sql( types=types, rename=rename, drop=drop, pk=pk, not_null=not_null, defaults=defaults, drop_foreign_keys=drop_foreign_keys, column_order=column_order, ) pragma_foreign_keys_was_on = self.db.execute("PRAGMA foreign_keys").fetchone()[ 0 ] try: if pragma_foreign_keys_was_on: self.db.execute("PRAGMA foreign_keys=0;") with self.db.conn: for sql in sqls: self.db.execute(sql) # Run the foreign_key_check before we commit if pragma_foreign_keys_was_on: self.db.execute("PRAGMA foreign_key_check;") finally: if pragma_foreign_keys_was_on: self.db.execute("PRAGMA foreign_keys=1;") return self def transform_sql( self, *, types=None, rename=None, drop=None, pk=DEFAULT, not_null=None, defaults=None, drop_foreign_keys=None, column_order=None, tmp_suffix=None, ): types = types or {} rename = rename or {} drop = drop or set() new_table_name = "{}_new_{}".format( self.name, tmp_suffix or os.urandom(6).hex() ) current_column_pairs = list(self.columns_dict.items()) new_column_pairs = [] copy_from_to = {column: column for column, _ in current_column_pairs} for name, type_ in current_column_pairs: type_ = types.get(name) or type_ if name in drop: del [copy_from_to[name]] continue new_name = rename.get(name) or name new_column_pairs.append((new_name, type_)) copy_from_to[name] = new_name sqls = [] if pk is DEFAULT: pks_renamed = tuple(rename.get(p) or p for p in self.pks) if len(pks_renamed) == 1: pk = pks_renamed[0] else: pk = pks_renamed # not_null may be a set or dict, need to convert to a set create_table_not_null = { rename.get(c.name) or c.name for c in self.columns if c.notnull if c.name not in drop } if isinstance(not_null, dict): # Remove any columns with a value of False for key, value in not_null.items(): # Column may have been renamed key = rename.get(key) or key if value is False and key in create_table_not_null: create_table_not_null.remove(key) else: create_table_not_null.add(key) elif isinstance(not_null, set): create_table_not_null.update((rename.get(k) or k) for k in not_null) elif not_null is None: pass else: assert False, "not_null must be a dict or a set or None" # defaults= create_table_defaults = { (rename.get(c.name) or c.name): c.default_value for c in self.columns if c.default_value is not None and c.name not in drop } if defaults is not None: create_table_defaults.update( {rename.get(c) or c: v for c, v in defaults.items()} ) # foreign_keys create_table_foreign_keys = [] for table, column, other_table, other_column in self.foreign_keys: if (drop_foreign_keys is None) or (column not in drop_foreign_keys): create_table_foreign_keys.append( (rename.get(column) or column, other_table, other_column) ) if column_order is not None: column_order = [rename.get(col) or col for col in column_order] sqls.append( self.db.create_table_sql( new_table_name, dict(new_column_pairs), pk=pk, not_null=create_table_not_null, defaults=create_table_defaults, foreign_keys=create_table_foreign_keys, column_order=column_order, ).strip() ) # Copy across data, respecting any renamed columns new_cols = [] old_cols = [] for from_, to_ in copy_from_to.items(): old_cols.append(from_) new_cols.append(to_) copy_sql = "INSERT INTO [{new_table}] ({new_cols})\n SELECT {old_cols} FROM [{old_table}];".format( new_table=new_table_name, old_table=self.name, old_cols=", ".join("[{}]".format(col) for col in old_cols), new_cols=", ".join("[{}]".format(col) for col in new_cols), ) sqls.append(copy_sql) # Drop the old table sqls.append("DROP TABLE [{}];".format(self.name)) # Rename the new one sqls.append( "ALTER TABLE [{}] RENAME TO [{}];".format(new_table_name, self.name) ) return sqls def extract(self, columns, table=None, fk_column=None, rename=None): rename = rename or {} if isinstance(columns, str): columns = [columns] if not set(columns).issubset(self.columns_dict.keys()): raise InvalidColumns( "Invalid columns {} for table with columns {}".format( columns, list(self.columns_dict.keys()) ) ) table = table or "_".join(columns) first_column = columns[0] pks = self.pks lookup_table = self.db[table] fk_column = fk_column or "{}_id".format(table) magic_lookup_column = "{}_{}".format(fk_column, os.urandom(6).hex()) # Populate the lookup table with all of the extracted unique values lookup_columns_definition = { (rename.get(col) or col): typ for col, typ in self.columns_dict.items() if col in columns } if lookup_table.exists(): if not set(lookup_columns_definition.items()).issubset( lookup_table.columns_dict.items() ): raise InvalidColumns( "Lookup table {} already exists but does not have columns {}".format( table, lookup_columns_definition ) ) else: lookup_table.create( { **{ "id": int, }, **lookup_columns_definition, }, pk="id", ) lookup_columns = [(rename.get(col) or col) for col in columns] lookup_table.create_index(lookup_columns, unique=True, if_not_exists=True) self.db.execute( "INSERT OR IGNORE INTO [{lookup_table}] ({lookup_columns}) SELECT DISTINCT {table_cols} FROM [{table}]".format( lookup_table=table, lookup_columns=", ".join("[{}]".format(c) for c in lookup_columns), table_cols=", ".join("[{}]".format(c) for c in columns), table=self.name, ) ) # Now add the new fk_column self.add_column(magic_lookup_column, int) # And populate it self.db.execute( "UPDATE [{table}] SET [{magic_lookup_column}] = (SELECT id FROM [{lookup_table}] WHERE {where})".format( table=self.name, magic_lookup_column=magic_lookup_column, lookup_table=table, where=" AND ".join( "[{table}].[{column}] = [{lookup_table}].[{lookup_column}]".format( table=self.name, lookup_table=table, column=column, lookup_column=rename.get(column) or column, ) for column in columns ), ) ) # Figure out the right column order column_order = [] for c in self.columns: if c.name in columns and magic_lookup_column not in column_order: column_order.append(magic_lookup_column) elif c.name == magic_lookup_column: continue else: column_order.append(c.name) # Drop the unnecessary columns and rename lookup column self.transform( drop=set(columns), rename={magic_lookup_column: fk_column}, column_order=column_order, ) # And add the foreign key constraint self.add_foreign_key(fk_column, table, "id") return self def create_index(self, columns, index_name=None, unique=False, if_not_exists=False): if index_name is None: index_name = "idx_{}_{}".format( self.name.replace(" ", "_"), "_".join(columns) ) sql = ( textwrap.dedent( """ CREATE {unique}INDEX {if_not_exists}[{index_name}] ON [{table_name}] ({columns}); """ ) .strip() .format( index_name=index_name, table_name=self.name, columns=", ".join("[{}]".format(c) for c in columns), unique="UNIQUE " if unique else "", if_not_exists="IF NOT EXISTS " if if_not_exists else "", ) ) self.db.execute(sql) return self def add_column( self, col_name, col_type=None, fk=None, fk_col=None, not_null_default=None ): fk_col_type = None if fk is not None: # fk must be a valid table if not fk in self.db.table_names(): raise AlterError("table '{}' does not exist".format(fk)) # if fk_col specified, must be a valid column if fk_col is not None: if fk_col not in self.db[fk].columns_dict: raise AlterError("table '{}' has no column {}".format(fk, fk_col)) else: # automatically set fk_col to first primary_key of fk table pks = [c for c in self.db[fk].columns if c.is_pk] if pks: fk_col = pks[0].name fk_col_type = pks[0].type else: fk_col = "rowid" fk_col_type = "INTEGER" if col_type is None: col_type = str not_null_sql = None if not_null_default is not None: not_null_sql = "NOT NULL DEFAULT {}".format( self.db.escape(not_null_default) ) sql = "ALTER TABLE [{table}] ADD COLUMN [{col_name}] {col_type}{not_null_default};".format( table=self.name, col_name=col_name, col_type=fk_col_type or COLUMN_TYPE_MAPPING[col_type], not_null_default=(" " + not_null_sql) if not_null_sql else "", ) self.db.execute(sql) if fk is not None: self.add_foreign_key(col_name, fk, fk_col) return self def drop(self): self.db.execute("DROP TABLE [{}]".format(self.name)) def guess_foreign_table(self, column): column = column.lower() possibilities = [column] if column.endswith("_id"): column_without_id = column[:-3] possibilities.append(column_without_id) if not column_without_id.endswith("s"): possibilities.append(column_without_id + "s") elif not column.endswith("s"): possibilities.append(column + "s") existing_tables = {t.lower(): t for t in self.db.table_names()} for table in possibilities: if table in existing_tables: return existing_tables[table] # If we get here there's no obvious candidate - raise an error raise NoObviousTable( "No obvious foreign key table for column '{}' - tried {}".format( column, repr(possibilities) ) ) def guess_foreign_column(self, other_table): pks = [c for c in self.db[other_table].columns if c.is_pk] if len(pks) != 1: raise BadPrimaryKey( "Could not detect single primary key for table '{}'".format(other_table) ) else: return pks[0].name def add_foreign_key( self, column, other_table=None, other_column=None, ignore=False ): # Ensure column exists if column not in self.columns_dict: raise AlterError("No such column: {}".format(column)) # If other_table is not specified, attempt to guess it from the column if other_table is None: other_table = self.guess_foreign_table(column) # If other_column is not specified, detect the primary key on other_table if other_column is None: other_column = self.guess_foreign_column(other_table) # Soundness check that the other column exists if ( not [c for c in self.db[other_table].columns if c.name == other_column] and other_column != "rowid" ): raise AlterError("No such column: {}.{}".format(other_table, other_column)) # Check we do not already have an existing foreign key if any( fk for fk in self.foreign_keys if fk.column == column and fk.other_table == other_table and fk.other_column == other_column ): if ignore: return self else: raise AlterError( "Foreign key already exists for {} => {}.{}".format( column, other_table, other_column ) ) self.db.add_foreign_keys([(self.name, column, other_table, other_column)]) return self def enable_fts( self, columns, fts_version="FTS5", create_triggers=False, tokenize=None, replace=False, ): "Enables FTS on the specified columns." create_fts_sql = ( textwrap.dedent( """ CREATE VIRTUAL TABLE [{table}_fts] USING {fts_version} ( {columns},{tokenize} content=[{table}] ) """ ) .strip() .format( table=self.name, columns=", ".join("[{}]".format(c) for c in columns), fts_version=fts_version, tokenize="\n tokenize='{}',".format(tokenize) if tokenize else "", ) ) should_recreate = False if replace and self.db["{}_fts".format(self.name)].exists(): # Does the table need to be recreated? fts_schema = self.db["{}_fts".format(self.name)].schema if fts_schema != create_fts_sql: should_recreate = True expected_triggers = {self.name + suffix for suffix in ("_ai", "_ad", "_au")} existing_triggers = {t.name for t in self.triggers} has_triggers = existing_triggers.issuperset(expected_triggers) if has_triggers != create_triggers: should_recreate = True if not should_recreate: # Table with correct configuration already exists return self if should_recreate: self.disable_fts() self.db.executescript(create_fts_sql) self.populate_fts(columns) if create_triggers: old_cols = ", ".join("old.[{}]".format(c) for c in columns) new_cols = ", ".join("new.[{}]".format(c) for c in columns) triggers = ( textwrap.dedent( """ CREATE TRIGGER [{table}_ai] AFTER INSERT ON [{table}] BEGIN INSERT INTO [{table}_fts] (rowid, {columns}) VALUES (new.rowid, {new_cols}); END; CREATE TRIGGER [{table}_ad] AFTER DELETE ON [{table}] BEGIN INSERT INTO [{table}_fts] ([{table}_fts], rowid, {columns}) VALUES('delete', old.rowid, {old_cols}); END; CREATE TRIGGER [{table}_au] AFTER UPDATE ON [{table}] BEGIN INSERT INTO [{table}_fts] ([{table}_fts], rowid, {columns}) VALUES('delete', old.rowid, {old_cols}); INSERT INTO [{table}_fts] (rowid, {columns}) VALUES (new.rowid, {new_cols}); END; """ ) .strip() .format( table=self.name, columns=", ".join("[{}]".format(c) for c in columns), old_cols=old_cols, new_cols=new_cols, ) ) self.db.executescript(triggers) return self def populate_fts(self, columns): sql = ( textwrap.dedent( """ INSERT INTO [{table}_fts] (rowid, {columns}) SELECT rowid, {columns} FROM [{table}]; """ ) .strip() .format( table=self.name, columns=", ".join("[{}]".format(c) for c in columns) ) ) self.db.executescript(sql) return self def disable_fts(self): fts_table = self.detect_fts() if fts_table: self.db[fts_table].drop() # Now delete the triggers that related to that table sql = ( textwrap.dedent( """ SELECT name FROM sqlite_master WHERE type = 'trigger' AND sql LIKE '% INSERT INTO [{}]%' """ ) .strip() .format(fts_table) ) trigger_names = [] for row in self.db.execute(sql).fetchall(): trigger_names.append(row[0]) with self.db.conn: for trigger_name in trigger_names: self.db.execute("DROP TRIGGER IF EXISTS [{}]".format(trigger_name)) return self def rebuild_fts(self): fts_table = self.detect_fts() if fts_table is None: # Assume this is itself an FTS table fts_table = self.name self.db.execute( "INSERT INTO [{table}]([{table}]) VALUES('rebuild');".format( table=fts_table ) ) return self def detect_fts(self): "Detect if table has a corresponding FTS virtual table and return it" sql = ( textwrap.dedent( """ SELECT name FROM sqlite_master WHERE rootpage = 0 AND ( sql LIKE '%VIRTUAL TABLE%USING FTS%content=%{table}%' OR ( tbl_name = "{table}" AND sql LIKE '%VIRTUAL TABLE%USING FTS%' ) ) """ ) .strip() .format(table=self.name) ) rows = self.db.execute(sql).fetchall() if len(rows) == 0: return None else: return rows[0][0] def optimize(self): fts_table = self.detect_fts() if fts_table is not None: self.db.execute( """ INSERT INTO [{table}] ([{table}]) VALUES ("optimize"); """.strip().format( table=fts_table ) ) return self def search_sql(self, columns=None, order=None, limit=None): # Pick names for table and rank column that don't clash original = "original_" if self.name == "original" else "original" rank = "rank" while rank in self.columns_dict: rank = rank + "_" columns_sql = "*" if columns: columns_sql = ", ".join("[{}]".format(c) for c in columns) fts_table = self.detect_fts() assert fts_table, "Full-text search is not configured for table '{}'".format( self.name ) return textwrap.dedent( """ with {original} as ( select rowid, {columns} from [{dbtable}] ) select {original}.*, [{fts}].rank as {rank} from [{original}] join [{fts}] on [{original}].rowid = [{fts}].rowid where [{fts}] match :query order by {order} {limit} """.format( dbtable=self.name, original=original, columns=columns_sql, rank=rank, fts=fts_table, order=order or "{} desc".format(rank), limit="limit {}".format(limit) if limit else "", ) ).strip() def search(self, q): sql = ( textwrap.dedent( """ select * from "{table}" where rowid in ( select rowid from [{table}_fts] where [{table}_fts] match :search ) order by rowid """ ) .strip() .format(table=self.name) ) return self.db.execute(sql, (q,)).fetchall() def value_or_default(self, key, value): return self._defaults[key] if value is DEFAULT else value def delete(self, pk_values): if not isinstance(pk_values, (list, tuple)): pk_values = [pk_values] self.get(pk_values) wheres = ["[{}] = ?".format(pk_name) for pk_name in self.pks] sql = "delete from [{table}] where {wheres}".format( table=self.name, wheres=" and ".join(wheres) ) with self.db.conn: self.db.execute(sql, pk_values) return self def delete_where(self, where=None, where_args=None): if not self.exists(): return [] sql = "delete from [{}]".format(self.name) if where is not None: sql += " where " + where self.db.execute(sql, where_args or []) return self def update(self, pk_values, updates=None, alter=False, conversions=None): updates = updates or {} conversions = conversions or {} if not isinstance(pk_values, (list, tuple)): pk_values = [pk_values] # Soundness check that the record exists (raises error if not): self.get(pk_values) if not updates: return self args = [] sets = [] wheres = [] pks = self.pks validate_column_names(updates.keys()) for key, value in updates.items(): sets.append("[{}] = {}".format(key, conversions.get(key, "?"))) args.append(value) wheres = ["[{}] = ?".format(pk_name) for pk_name in pks] args.extend(pk_values) sql = "update [{table}] set {sets} where {wheres}".format( table=self.name, sets=", ".join(sets), wheres=" and ".join(wheres) ) with self.db.conn: try: rowcount = self.db.execute(sql, args).rowcount except OperationalError as e: if alter and (" column" in e.args[0]): # Attempt to add any missing columns, then try again self.add_missing_columns([updates]) rowcount = self.db.execute(sql, args).rowcount else: raise # TODO: Test this works (rolls back) - use better exception: assert rowcount == 1 self.last_pk = pk_values[0] if len(pks) == 1 else pk_values return self def build_insert_queries_and_params( self, extracts, chunk, all_columns, hash_id, upsert, pk, conversions, num_records_processed, replace, ignore, ): # values is the list of insert data that is passed to the # .execute() method - but some of them may be replaced by # new primary keys if we are extracting any columns. values = [] extracts = resolve_extracts(extracts) for record in chunk: record_values = [] for key in all_columns: value = jsonify_if_needed( record.get(key, None if key != hash_id else _hash(record)) ) if key in extracts: extract_table = extracts[key] value = self.db[extract_table].lookup({"value": value}) record_values.append(value) values.append(record_values) queries_and_params = [] if upsert: if isinstance(pk, str): pks = [pk] else: pks = pk self.last_pk = None for record_values in values: # TODO: make more efficient: record = dict(zip(all_columns, record_values)) sql = "INSERT OR IGNORE INTO [{table}]({pks}) VALUES({pk_placeholders});".format( table=self.name, pks=", ".join(["[{}]".format(p) for p in pks]), pk_placeholders=", ".join(["?" for p in pks]), ) queries_and_params.append((sql, [record[col] for col in pks])) # UPDATE [book] SET [name] = 'Programming' WHERE [id] = 1001; set_cols = [col for col in all_columns if col not in pks] sql2 = "UPDATE [{table}] SET {pairs} WHERE {wheres}".format( table=self.name, pairs=", ".join( "[{}] = {}".format(col, conversions.get(col, "?")) for col in set_cols ), wheres=" AND ".join("[{}] = ?".format(pk) for pk in pks), ) queries_and_params.append( ( sql2, [record[col] for col in set_cols] + [record[pk] for pk in pks], ) ) # We can populate .last_pk right here if num_records_processed == 1: self.last_pk = tuple(record[pk] for pk in pks) if len(self.last_pk) == 1: self.last_pk = self.last_pk[0] else: or_what = "" if replace: or_what = "OR REPLACE " elif ignore: or_what = "OR IGNORE " sql = """ INSERT {or_what}INTO [{table}] ({columns}) VALUES {rows}; """.strip().format( or_what=or_what, table=self.name, columns=", ".join("[{}]".format(c) for c in all_columns), rows=", ".join( "({placeholders})".format( placeholders=", ".join( [conversions.get(col, "?") for col in all_columns] ) ) for record in chunk ), ) flat_values = list(itertools.chain(*values)) queries_and_params = [(sql, flat_values)] return queries_and_params def insert_chunk( self, alter, extracts, chunk, all_columns, hash_id, upsert, pk, conversions, num_records_processed, replace, ignore, ): queries_and_params = self.build_insert_queries_and_params( extracts, chunk, all_columns, hash_id, upsert, pk, conversions, num_records_processed, replace, ignore, ) with self.db.conn: for query, params in queries_and_params: try: result = self.db.execute(query, params) except OperationalError as e: if alter and (" column" in e.args[0]): # Attempt to add any missing columns, then try again self.add_missing_columns(chunk) result = self.db.execute(query, params) elif e.args[0] == "too many SQL variables": first_half = chunk[: len(chunk) // 2] second_half = chunk[len(chunk) // 2 :] self.insert_chunk( alter, extracts, first_half, all_columns, hash_id, upsert, pk, conversions, num_records_processed, replace, ignore, ) self.insert_chunk( alter, extracts, second_half, all_columns, hash_id, upsert, pk, conversions, num_records_processed, replace, ignore, ) else: raise if num_records_processed == 1 and not upsert: self.last_rowid = result.lastrowid self.last_pk = self.last_rowid # self.last_rowid will be 0 if a "INSERT OR IGNORE" happened if (hash_id or pk) and self.last_rowid: row = list(self.rows_where("rowid = ?", [self.last_rowid]))[0] if hash_id: self.last_pk = row[hash_id] elif isinstance(pk, str): self.last_pk = row[pk] else: self.last_pk = tuple(row[p] for p in pk) return def insert( self, record, pk=DEFAULT, foreign_keys=DEFAULT, column_order=DEFAULT, not_null=DEFAULT, defaults=DEFAULT, hash_id=DEFAULT, alter=DEFAULT, ignore=DEFAULT, replace=DEFAULT, extracts=DEFAULT, conversions=DEFAULT, columns=DEFAULT, ): return self.insert_all( [record], pk=pk, foreign_keys=foreign_keys, column_order=column_order, not_null=not_null, defaults=defaults, hash_id=hash_id, alter=alter, ignore=ignore, replace=replace, extracts=extracts, conversions=conversions, columns=columns, ) def insert_all( self, records, pk=DEFAULT, foreign_keys=DEFAULT, column_order=DEFAULT, not_null=DEFAULT, defaults=DEFAULT, batch_size=DEFAULT, hash_id=DEFAULT, alter=DEFAULT, ignore=DEFAULT, replace=DEFAULT, truncate=False, extracts=DEFAULT, conversions=DEFAULT, columns=DEFAULT, upsert=False, ): """ Like .insert() but takes a list of records and ensures that the table that it creates (if table does not exist) has columns for ALL of that data """ pk = self.value_or_default("pk", pk) foreign_keys = self.value_or_default("foreign_keys", foreign_keys) column_order = self.value_or_default("column_order", column_order) not_null = self.value_or_default("not_null", not_null) defaults = self.value_or_default("defaults", defaults) batch_size = self.value_or_default("batch_size", batch_size) hash_id = self.value_or_default("hash_id", hash_id) alter = self.value_or_default("alter", alter) ignore = self.value_or_default("ignore", ignore) replace = self.value_or_default("replace", replace) extracts = self.value_or_default("extracts", extracts) conversions = self.value_or_default("conversions", conversions) columns = self.value_or_default("columns", columns) if upsert and (not pk and not hash_id): raise PrimaryKeyRequired("upsert() requires a pk") assert not (hash_id and pk), "Use either pk= or hash_id=" if hash_id: pk = hash_id assert not ( ignore and replace ), "Use either ignore=True or replace=True, not both" all_columns = None first = True num_records_processed = 0 # We can only handle a max of 999 variables in a SQL insert, so # we need to adjust the batch_size down if we have too many cols records = iter(records) # Peek at first record to count its columns: try: first_record = next(records) except StopIteration: return self # It was an empty list num_columns = len(first_record.keys()) assert ( num_columns <= SQLITE_MAX_VARS ), "Rows can have a maximum of {} columns".format(SQLITE_MAX_VARS) batch_size = max(1, min(batch_size, SQLITE_MAX_VARS // num_columns)) self.last_rowid = None self.last_pk = None if truncate and self.exists(): self.db.execute("DELETE FROM [{}];".format(self.name)) for chunk in chunks(itertools.chain([first_record], records), batch_size): chunk = list(chunk) num_records_processed += len(chunk) if first: if not self.exists(): # Use the first batch to derive the table names column_types = suggest_column_types(chunk) column_types.update(columns or {}) self.create( column_types, pk, foreign_keys, column_order=column_order, not_null=not_null, defaults=defaults, hash_id=hash_id, extracts=extracts, ) all_columns = set() for record in chunk: all_columns.update(record.keys()) all_columns = list(sorted(all_columns)) if hash_id: all_columns.insert(0, hash_id) else: all_columns += [ column for record in chunk for column in record if column not in all_columns ] validate_column_names(all_columns) first = False self.insert_chunk( alter, extracts, chunk, all_columns, hash_id, upsert, pk, conversions, num_records_processed, replace, ignore, ) return self def upsert( self, record, pk=DEFAULT, foreign_keys=DEFAULT, column_order=DEFAULT, not_null=DEFAULT, defaults=DEFAULT, hash_id=DEFAULT, alter=DEFAULT, extracts=DEFAULT, conversions=DEFAULT, columns=DEFAULT, ): return self.upsert_all( [record], pk=pk, foreign_keys=foreign_keys, column_order=column_order, not_null=not_null, defaults=defaults, hash_id=hash_id, alter=alter, extracts=extracts, conversions=conversions, columns=columns, ) def upsert_all( self, records, pk=DEFAULT, foreign_keys=DEFAULT, column_order=DEFAULT, not_null=DEFAULT, defaults=DEFAULT, batch_size=DEFAULT, hash_id=DEFAULT, alter=DEFAULT, extracts=DEFAULT, conversions=DEFAULT, columns=DEFAULT, ): return self.insert_all( records, pk=pk, foreign_keys=foreign_keys, column_order=column_order, not_null=not_null, defaults=defaults, batch_size=batch_size, hash_id=hash_id, alter=alter, extracts=extracts, conversions=conversions, columns=columns, upsert=True, ) def add_missing_columns(self, records): needed_columns = suggest_column_types(records) current_columns = self.columns_dict for col_name, col_type in needed_columns.items(): if col_name not in current_columns: self.add_column(col_name, col_type) return self def lookup(self, column_values): # lookups is a dictionary - all columns will be used for a unique index assert isinstance(column_values, dict) if self.exists(): self.add_missing_columns([column_values]) unique_column_sets = [set(i.columns) for i in self.indexes] if set(column_values.keys()) not in unique_column_sets: self.create_index(column_values.keys(), unique=True) wheres = ["[{}] = ?".format(column) for column in column_values] rows = list( self.rows_where( " and ".join(wheres), [value for _, value in column_values.items()] ) ) try: return rows[0]["id"] except IndexError: return self.insert(column_values, pk="id").last_pk else: pk = self.insert(column_values, pk="id").last_pk self.create_index(column_values.keys(), unique=True) return pk def m2m( self, other_table, record_or_iterable=None, pk=DEFAULT, lookup=None, m2m_table=None, ): if isinstance(other_table, str): other_table = self.db.table(other_table, pk=pk) our_id = self.last_pk if lookup is not None: assert record_or_iterable is None, "Provide lookup= or record, not both" else: assert record_or_iterable is not None, "Provide lookup= or record, not both" tables = list(sorted([self.name, other_table.name])) columns = ["{}_id".format(t) for t in tables] if m2m_table is not None: m2m_table_name = m2m_table else: # Detect if there is a single, unambiguous option candidates = self.db.m2m_table_candidates(self.name, other_table.name) if len(candidates) == 1: m2m_table_name = candidates[0] elif len(candidates) > 1: raise NoObviousTable( "No single obvious m2m table for {}, {} - use m2m_table= parameter".format( self.name, other_table.name ) ) else: # If not, create a new table m2m_table_name = m2m_table or "{}_{}".format(*tables) m2m_table = self.db.table(m2m_table_name, pk=columns, foreign_keys=columns) if lookup is None: # if records is only one record, put the record in a list records = ( [record_or_iterable] if isinstance(record_or_iterable, Mapping) else record_or_iterable ) # Ensure each record exists in other table for record in records: id = other_table.insert(record, pk=pk, replace=True).last_pk m2m_table.insert( { "{}_id".format(other_table.name): id, "{}_id".format(self.name): our_id, }, replace=True, ) else: id = other_table.lookup(lookup) m2m_table.insert( { "{}_id".format(other_table.name): id, "{}_id".format(self.name): our_id, }, replace=True, ) return self class View(Queryable): def exists(self): return True def __repr__(self): return "".format( self.name, ", ".join(c.name for c in self.columns) ) def drop(self): self.db.execute("DROP VIEW [{}]".format(self.name)) def chunks(sequence, size): iterator = iter(sequence) for item in iterator: yield itertools.chain([item], itertools.islice(iterator, size - 1)) def jsonify_if_needed(value): if isinstance(value, decimal.Decimal): return float(value) if isinstance(value, (dict, list, tuple)): return json.dumps(value, default=repr) elif isinstance(value, (datetime.time, datetime.date, datetime.datetime)): return value.isoformat() elif isinstance(value, uuid.UUID): return str(value) else: return value def _hash(record): return hashlib.sha1( json.dumps(record, separators=(",", ":"), sort_keys=True, default=repr).encode( "utf8" ) ).hexdigest() def resolve_extracts(extracts): if extracts is None: extracts = {} if isinstance(extracts, (list, tuple)): extracts = {item: item for item in extracts} return extracts def validate_column_names(columns): # Validate no columns contain '[' or ']' - #86 for column in columns: assert ( "[" not in column and "]" not in column ), "'[' and ']' cannot be used in column names"