mirror of
https://github.com/sqlalchemy/sqlalchemy.git
synced 2026-05-15 05:07:16 -04:00
Mike Bayer
102 lines
2.4 KiB
Myghty
102 lines
2.4 KiB
Myghty
<%flags>inherit='document_base.myt'</%flags>
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<&|doclib.myt:item, name="coolthings", description="Cool Things You Can Do With SQLAlchemy" &>
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<&|formatting.myt:code, syntaxtype="python" &>
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# first, some imports
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from sqlalchemy.sql import *
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from sqlalchemy.schema import *
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# make a database engine based on sqlite
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import sqlalchemy.databases.sqlite as sqlite_db
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db = sqlite_db.engine('foo.db', pool_size = 10, max_overflow = 5)
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# define metadata for a table
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users = Table('users', db,
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Column('user_id', INT),
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Column('user_name', VARCHAR(20)),
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Column('password', CHAR(10))
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)
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# select rows from the table
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query = users.select()
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cursor = query.execute()
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rows = cursor.fetchall()
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# select rows from the table where user_name=='ed'
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rows = users.select(users.c.user_name == 'ed').execute().fetchall()
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# make a query with a bind param
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query = select([users], users.c.user_id == bindparam('userid'))
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# execute with params
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rows = query.execute(userid = 7).fetchall()
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# make another table
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addresses = Table('addresses', db,
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Column('address_id', INT),
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Column('user_id', INT),
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Column('street', VARCHAR(20)),
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Column('city', VARCHAR(20)),
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Column('state', CHAR(2)),
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Column('zip', CHAR(5))
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)
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# no, really, make this table in the DB via CREATE
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addresses.build()
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# make a nonsensical query that selects from an outer join, and
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# throws in a literally-defined EXISTS clause
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query = select(
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[users, addresses],
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and_(
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addresses.c.street == 'Green Street',
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addresses.c.city == 'New York',
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users.c.user_id != 12,
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"EXISTS (select 1 from special_table where user_id=users.user_id)"
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),
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from_obj = [ outerjoin(users, addresses, addresses.user_id==users.user_id) ]
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)
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# insert into a table
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users.insert().execute(user_id = 7, user_name = 'jack')
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# update the table
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users.update(users.c.user_id == 7).execute(user_name = 'fred')
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# get DBAPI connections from the higher-level engine
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c = db.connection()
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# use the connection pooling directly:
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# import a real DBAPI database
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from pysqlite2 import dbapi2 as sqlite
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# make an implicit pool around it
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import sqlalchemy.pool as pool
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sqlite = pool.manage(sqlite, pool_size = 10, max_overflow = 5, use_threadlocal = True)
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# get a pooled connection local to the current thread
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c = sqlite.connect('foo.db')
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cursor = c.cursor()
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# return the connection to the pool
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cursor = None
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c = None
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</&>
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</&>
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