Question

SQLAlchemy是否支持H2 db？我正在使用金字塔，并希望连接到H2 db数据库。如果使用postgres方言，我会收到如下错误：

File "/Users/homecamera/gotocamera/hcadmin/env/lib/python2.7/site-packages/SQLAlchemy-0.7.3-py2.7-macosx-10.4-x86_64.egg/sqlalchemy/dialects/postgresql/base.py", line 871, in initialize
super(PGDialect, self).initialize(connection)
File "/Users/homecamera/gotocamera/hcadmin/env/lib/python2.7/site-packages/SQLAlchemy-0.7.3-py2.7-macosx-10.4-x86_64.egg/sqlalchemy/engine/default.py", line 181, in initialize
self.get_isolation_level(connection.connection)
File "/Users/homecamera/gotocamera/hcadmin/env/lib/python2.7/site-packages/SQLAlchemy-0.7.3-py2.7-macosx-10.4-x86_64.egg/sqlalchemy/dialects/postgresql/base.py", line 910, in get_isolation_level
cursor.execute('show transaction isolation level')
ProgrammingError: Syntax error in SQL statement "SELECT "; expected "TOP, LIMIT, DISTINCT, ALL, *, NOT, EXISTS"; SQL statement:
show transaction isolation level [42001-140]
DETAIL:  org.h2.jdbc.JdbcSQLException: Syntax error in SQL statement "SELECT "; expected "TOP, LIMIT, DISTINCT, ALL, *, NOT, EXISTS"; SQL statement:
show transaction isolation level [42001-140]

Answer 1

AFAIK对HSQLDB方言或原生H2方言没有官方支持。使用Postgres方言和H2（不使用HSQLDB）肯定会导致错误。

尝试sqlalchemy-jython和使用H2方言可能会更好。

Answer 2

以防万一有人再次发现这种情况，我试图让它运行（作为sqlite的替代品）并且它只是部分工作，并且唯一有效的驱动程序是pg8000。

使用以下服务器运行服务器：

nohup java -cp /opt/h2/bin/h2*.jar org.h2.tools.Server -pg -pgAllowOthers -pgPort 5435 -baseDir /opt/h2-data &

此代码适用于sqlalchemy：

from sqlalchemy import create_engine
engine = create_engine('postgresql+pg8000://sa:sa@localhost:5435/main')
engine.execute("SELECT 1")

但是这段代码会引发异常：来自sqlalchemy_utils import create_database create_database（ '的PostgreSQL + pg8000：// SA：SA @本地：5435 /主'）

例外：

sqlalchemy.exc.ProgrammingError: (pg8000.core.ProgrammingError) ('ERROR', 
'HY000', 'General error: "java.lang.IllegalStateException: output binary 
format is undefined" [50000-196]', 'org.h2.jdbc.JdbcSQLException: General
error: "java.lang.IllegalStateException: output binary format is undefined"
[50000-196]') [SQL: 'select version()']

SQLAlchemy是否支持H2DB？

2 个答案: