h2（嵌入模式）数据库文件问题 [英] h2 (embedded mode ) database files problem
问题描述
我的src目录中有一个h2-database文件（Java，Eclipse）：h2test.db
There is a h2-database file in my src directory (Java, Eclipse): h2test.db
问题：
-
从命令行启动h2.jar（以及端口8082上的h2浏览器界面），我创建了2个表，'test1'和'test2'在h2test.db中我已经放了一些数据;
starting the h2.jar from the command line (and thus the h2 browser interface on port 8082), I have created 2 tables, 'test1' and 'test2' in h2test.db and I have put some data in them;
当试图从java代码（JDBC）访问它们时，它会抛出找不到表例外。 java代码中的show tables显示了一个0行的结果集。
when trying to access them from java code (JDBC), it throws me "table not found exception". A "show tables" from the java code shows a resultset with 0 rows.
此外，从java代码（CREATE TABLE ...等）创建新表（'newtest'）时，我在启动时无法看到它之后的h2.jar浏览器界面;只显示了其他两个表（'test1'和'test2'）（但随后可以从java代码中访问新创建的表'newtest'）。
Also, when creating a new table ('newtest') from the java code (CREATE TABLE ... etc), I cannot see it when starting the h2.jar browser interface afterwards; just the other two tables ('test1' and 'test2') are shown (but then the newly created table 'newtest' is accessible from the java code).
我对嵌入式数据库缺乏经验;我相信我在这里做了一些根本错误的事情。我的假设是，我正在访问同一个文件 - 一次来自java应用程序，一次来自h2控制台 - 浏览器界面。我似乎无法理解，我在这里做错了什么？
I'm inexperienced with embedded databases; I believe I'm doing something fundamentally wrong here. My assumption is, that I'm accessing the same file - once from the java app, and once from the h2 console-browser interface. I cannot seem to understand it, what am I doing wrong here?
编辑：根据要求，添加一些代码：
as requested, adding some code:
Java代码：
Class.forName("org.h2.Driver");
String url = "jdbc:h2:" + "db/h2test.db";
String user = "aeter";
String password = "aeter";
Connection conn = DriverManager.getConnection(url, user, password);
PreparedStatement ps2 = conn.prepareStatement("Show tables;");
ResultSet rs = ps2.executeQuery();此结果集有0行（无表），而不是给我看了2个表。
This resultset has 0 rows (no tables), instead of showing me the 2 tables.
H2控制台 - 浏览器界面设置：
H2 Console-browser interface settings:
Settings: Generic h2(embedded)
driver class: org.h2.Driver
JDBC URL: jdbc:h2:../../workspace/project_name/src/db/h2test.db
user name: aeter
password: aeter
EDIT2：我将数据库复制到新文件夹。现在，新文件夹中的db文件显示为'newtest'表（来自java代码），并带有'test1'和'test2'表（来自console-browser h2接口） - 与旧数据库完全相同文件显示。因此，db文件的副本仍然存在问题。
I copied the database to a new folder. Now the db file in the new folder is shown with the 'newtest' table (from the java code) and with the 'test1' and 'test2' tables (from the console-browser h2 interface) - exactly the same way the older db file was shown. So the problem persists with the copy of the db file.
推荐答案
对于嵌入式模式，您需要检查路径。例如，使用相对于主目录的路径：
For embedded mode, you'll need to check the path. For example, use a path relative to your home directory:
"jdbc:h2:file:~/db/h2test.db"
可以肯定的是，使用完整路径：
To be sure, use a full path:
"jdbc:h2:file:/users/aeter/db/h2test.db"
为方便起见，附加; IFEXISTS = TRUE 以避免创建虚假的数据库文件。
For convenience, append ;IFEXISTS=TRUE to avoid creating spurious database files.
请参阅 使用JDBC连接数据库 更多。
See Connecting to a Database using JDBC for more.
H2 服务器 URL相对于 -baseDir 指定为 main（）的参数。
H2 Server URLs are relative to the -baseDir specified as a parameter to main().
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