/Users/song/Code/sqlalchemy_learn_20230210/le00.py

from sqlalchemy import Column, String, create_engine,Integer
from sqlalchemy.orm import sessionmaker,declarative_base

engine = create_engine('sqlite:///le00.db')
session =sessionmaker(bind=engine)()


Base =declarative_base()

class User(Base):

    __tablename__ = 'user'

    username = Column(String,primary_key=True)
    age = Column(Integer)

    def __init__(self,username,age) -> None:
        self.username = username
        self.age = age
        

alice = User('alice',10)
bruce = User('bruce',20)
session.add(alice)
session.add(bruce)
session.commit()

declarative_base导入路径变化

(venv) song@songdeMBP sqlalchemy_learn_20230210 % python3 le00.py

/Users/song/Code/sqlalchemy_learn_20230210/le00.py:9: MovedIn20Warning: The ``declarative_base()`` function is now
available as sqlalchemy.orm.declarative_base(). (deprecated since: 2.0) (Background on SQLAlchemy 2.0 at:
https://sqlalche.me/e/b8d9)
Base =declarative_base()

sqlite3.OperationalError: no such table: user

Traceback (most recent call last):
File "/Users/song/Code/sqlalchemy_learn_20230210/venv/lib/python3.11/site-packages/sqlalchemy/engine/base.py", line
1964, in _exec_single_context
self.dialect.do_execute(
File "/Users/song/Code/sqlalchemy_learn_20230210/venv/lib/python3.11/site-packages/sqlalchemy/engine/default.py", line
747, in do_execute
cursor.execute(statement, parameters)
sqlite3.OperationalError: no such table: user

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
File "/Users/song/Code/sqlalchemy_learn_20230210/le00.py", line 25, in <module>
    session.commit()
    File "/Users/song/Code/sqlalchemy_learn_20230210/venv/lib/python3.11/site-packages/sqlalchemy/orm/session.py", line
    1903, in commit
    trans.commit(_to_root=True)
    File "<string>", line 2, in commit
        File
        "/Users/song/Code/sqlalchemy_learn_20230210/venv/lib/python3.11/site-packages/sqlalchemy/orm/state_changes.py",
        line 137, in _go
        ret_value = fn(self, *arg, **kw)
        ^^^^^^^^^^^^^^^^^^^^
        File "/Users/song/Code/sqlalchemy_learn_20230210/venv/lib/python3.11/site-packages/sqlalchemy/orm/session.py",
        line 1218, in commit
        self._prepare_impl()
        File "<string>", line 2, in _prepare_impl
            File
            "/Users/song/Code/sqlalchemy_learn_20230210/venv/lib/python3.11/site-packages/sqlalchemy/orm/state_changes.py",
            line 137, in _go
            ret_value = fn(self, *arg, **kw)
            ^^^^^^^^^^^^^^^^^^^^
            File
            "/Users/song/Code/sqlalchemy_learn_20230210/venv/lib/python3.11/site-packages/sqlalchemy/orm/session.py",
            line 1193, in _prepare_impl
            self.session.flush()
            File
            "/Users/song/Code/sqlalchemy_learn_20230210/venv/lib/python3.11/site-packages/sqlalchemy/orm/session.py",
            line 4140, in flush
            self._flush(objects)
            File
            "/Users/song/Code/sqlalchemy_learn_20230210/venv/lib/python3.11/site-packages/sqlalchemy/orm/session.py",
            line 4276, in _flush
            with util.safe_reraise():
            File
            "/Users/song/Code/sqlalchemy_learn_20230210/venv/lib/python3.11/site-packages/sqlalchemy/util/langhelpers.py",
            line 147, in __exit__
            raise exc_value.with_traceback(exc_tb)
            File
            "/Users/song/Code/sqlalchemy_learn_20230210/venv/lib/python3.11/site-packages/sqlalchemy/orm/session.py",
            line 4237, in _flush
            flush_context.execute()
            File
            "/Users/song/Code/sqlalchemy_learn_20230210/venv/lib/python3.11/site-packages/sqlalchemy/orm/unitofwork.py",
            line 467, in execute
            rec.execute(self)
            File
            "/Users/song/Code/sqlalchemy_learn_20230210/venv/lib/python3.11/site-packages/sqlalchemy/orm/unitofwork.py",
            line 644, in execute
            util.preloaded.orm_persistence.save_obj(
            File
            "/Users/song/Code/sqlalchemy_learn_20230210/venv/lib/python3.11/site-packages/sqlalchemy/orm/persistence.py",
            line 93, in save_obj
            _emit_insert_statements(
            File
            "/Users/song/Code/sqlalchemy_learn_20230210/venv/lib/python3.11/site-packages/sqlalchemy/orm/persistence.py",
            line 1024, in _emit_insert_statements
            result = connection.execute(
            ^^^^^^^^^^^^^^^^^^^
            File
            "/Users/song/Code/sqlalchemy_learn_20230210/venv/lib/python3.11/site-packages/sqlalchemy/engine/base.py",
            line 1414, in execute
            return meth(
            (venv) song@songdeMBP sqlalchemy_learn_20230210 % python3 le00.py
            Traceback (most recent call last):
            File
            "/Users/song/Code/sqlalchemy_learn_20230210/venv/lib/python3.11/site-packages/sqlalchemy/engine/base.py",
            line 1964, in _exec_single_context
            self.dialect.do_execute(
            File
            "/Users/song/Code/sqlalchemy_learn_20230210/venv/lib/python3.11/site-packages/sqlalchemy/engine/default.py",
            line 747, in do_execute
            cursor.execute(statement, parameters)
            sqlite3.OperationalError: no such table: user

            The above exception was the direct cause of the following exception:

            Traceback (most recent call last):
            File "/Users/song/Code/sqlalchemy_learn_20230210/le00.py", line 24, in <module>
                session.commit()

sqlite 的命令

 (venv) song@songdeMBP sqlalchemy_learn_20230210 % sqlite3 le00.db
 SQLite version 3.39.5 2022-10-14 20:58:05
 Enter ".help" for usage hints.
 sqlite> .db
 Error: unknown command or invalid arguments: "db". Enter ".help" for help

.help

sqlite> .help
.auth ON|OFF Show authorizer callbacks
.backup ?DB? FILE Backup DB (default "main") to FILE
.bail on|off Stop after hitting an error. Default OFF
.binary on|off Turn binary output on or off. Default OFF
.cd DIRECTORY Change the working directory to DIRECTORY
.changes on|off Show number of rows changed by SQL
.check GLOB Fail if output since .testcase does not match
.clone NEWDB Clone data into NEWDB from the existing database
.connection [close] [#] Open or close an auxiliary database connection
.databases List names and files of attached databases
.dbconfig ?op? ?val? List or change sqlite3_db_config() options
.dbinfo ?DB? Show status information about the database
.dump ?OBJECTS? Render database content as SQL
.echo on|off Turn command echo on or off
.eqp on|off|full|... Enable or disable automatic EXPLAIN QUERY PLAN
.excel Display the output of next command in spreadsheet
.exit ?CODE? Exit this program with return-code CODE
.expert EXPERIMENTAL. Suggest indexes for queries
.explain ?on|off|auto? Change the EXPLAIN formatting mode. Default: auto
.filectrl CMD ... Run various sqlite3_file_control() operations
.fullschema ?--indent? Show schema and the content of sqlite_stat tables
.headers on|off Turn display of headers on or off
.help ?-all? ?PATTERN? Show help text for PATTERN
.hex-rekey OLD NEW NEW Change the encryption key using hexadecimal
.import FILE TABLE Import data from FILE into TABLE
.import FILE TABLE Import data from FILE into TABLE
.imposter INDEX TABLE Create imposter table TABLE on index INDEX
.indexes ?TABLE? Show names of indexes
.limit ?LIMIT? ?VAL? Display or change the value of an SQLITE_LIMIT
.lint OPTIONS Report potential schema issues.
.log FILE|off Turn logging on or off. FILE can be stderr/stdout
.mode MODE ?OPTIONS? Set output mode
.nonce STRING Suspend safe mode for one command if nonce matches
.nullvalue STRING Use STRING in place of NULL values
.once ?OPTIONS? ?FILE? Output for the next SQL command only to FILE
.open ?OPTIONS? ?FILE? Close existing database and reopen FILE
.output ?FILE? Send output to FILE or stdout if FILE is omitted
.parameter CMD ... Manage SQL parameter bindings
.print STRING... Print literal STRING
.progress N Invoke progress handler after every N opcodes
.prompt MAIN CONTINUE Replace the standard prompts
.quit Exit this program
.read FILE Read input from FILE or command output
.rekey OLD NEW NEW Change the encryption key
.recover Recover as much data as possible from corrupt db.
.restore ?DB? FILE Restore content of DB (default "main") from FILE
.save ?OPTIONS? FILE Write database to FILE (an alias for .backup ...)
.scanstats on|off Turn sqlite3_stmt_scanstatus() metrics on or off
.schema ?PATTERN? Show the CREATE statements matching PATTERN
.selftest ?OPTIONS? Run tests defined in the SELFTEST table
.separator COL ?ROW? Change the column and row separators
.session ?NAME? CMD ... Create or control sessions
.sha3sum ... Compute a SHA3 hash of database content
.shell CMD ARGS... Run CMD ARGS... in a system shell
# sqlite 创建数据库

 (venv) song@songdeMBP sqlalchemy_learn_20230210 % sqlite3 le00.db
 SQLite version 3.39.5 2022-10-14 20:58:05
 Enter ".help" for usage hints.
 sqlite> .tables
 sqlite> create table user(username text primary key,age int); 
 sqlite> .tables
 user
 sqlite> .quit

sqlite3.IntegrityError: UNIQUE constraint failed: user.username

 (venv) song@songdeMBP sqlalchemy_learn_20230210 % python3 le00.py

 Traceback (most recent call last):
 File
 "/Users/song/Code/sqlalchemy_learn_20230210/venv/lib/python3.11/site-packages/sqlalchemy/engine/base.py",
 line 1933, in _exec_single_context
 self.dialect.do_executemany(
 File
 "/Users/song/Code/sqlalchemy_learn_20230210/venv/lib/python3.11/site-packages/sqlalchemy/engine/default.py",
 line 744, in do_executemany
 cursor.executemany(statement, parameters)
 sqlite3.IntegrityError: UNIQUE constraint failed: user.username

 The above exception was the direct cause of the following exception:

 Traceback (most recent call last):
 File "/Users/song/Code/sqlalchemy_learn_20230210/le00.py", line 28, in
 <module>
     session.commit()

导出shell命令的历史记录

 % history 0 > shell_history.txt
 (venv) song@songdeMBP sqlalchemy_learn_20230210