执行多行查询不适用于 table 别名，而单行查询可以

Question

这是我第一次使用 ucanaccess，因为我刚刚发现我以前的 Eclipse 版本不能与 Java 1.8 一起使用，所以我可以访问我的 Access 数据库。我熟悉 Java 编程和 RDBMS（目前使用 Oracle），所以我不明白为什么我的代码会出错。

这是我用来连接DB的代码（变量dbFile是一个File对象，用来存储Access DB路径）：

  try
  {
   String urlDB = "jdbc:ucanaccess://"+ dbFile.getAbsolutePath();
   
   Connection conn = DriverManager.getConnection(urlDB, "", "");
   System.out.println("Connection Successful\n");
   
   Statement test = conn.createStatement();
/*   ResultSet rs = test.executeQuery("SELECT e.* "
                                                       + "FROM Employees e"
                                                       + "WHERE e.EmployeeNo LIKE 'H%'" 
                                                       + "ORDER BY e.LastName");

   System.out.println(); //spacing

   //retrieve column data
   while(rs.next())
   {
    //can get data by column name instead of ID
    String id = rs.getString("ID");
    String fName = rs.getString("FirstName");
    String lName = rs.getString("LastName");
    String dName = rs.getString("DisplayName");
      
    System.out.println(id + "\t" + fName + "\t" + lName + "\t");
    
   }
*/   
   ResultSet rs = test.executeQuery("SELECT e.* FROM Employees e WHERE e.EmployeeNo LIKE '1%' ORDER BY e.LastName");
   
   //get table information (i.e. column names)
   ResultSetMetaData rsmd = rs.getMetaData();
   int dbColumnCount = rsmd.getColumnCount();
   
/*   //db columns starts at 1 not 0
   for (int count = 1; count <= dbColumnCount; count++)
   {
    System.out.print(rsmd.getColumnName(count) + "\t");
   }
*/   
   System.out.format("%5s%10s%15s%20s%n", rsmd.getColumnName(1), rsmd.getColumnName(2),
     rsmd.getColumnName(3), rsmd.getColumnName(4));
   //System.out.println();
   
   while(rs.next())
   {
    //can get data by column name instead of ID
    String id = rs.getString("ID");
    String fName = rs.getString("FirstName");
    String lName = rs.getString("LastName");
    String dName = rs.getString("DisplayName");
      
    //System.out.println(id + "\t" + fName + "\t" + lName + "\t");
    System.out.format("%5s%10s%15s%20s%n", id, fName, lName, dName);
   }
   
  }
  catch (Exception e)
  {
   e.printStackTrace();
   System.err.println("Could not connect to the Database");
   System.err.println(e.getMessage());
  }  
 }

第一次调用 ResultSet（多行查询）抛出以下异常：

net.ucanaccess.jdbc.UcanaccessSQLException: UCAExc:::4.0.0 user lacks privilege or object not found: E
 at net.ucanaccess.jdbc.UcanaccessStatement.executeQuery(UcanaccessStatement.java:210)
 at DBConnect.<init>(InOutBoard.java:78)
 at InOutBoard.main(InOutBoard.java:47)
Caused by: java.sql.SQLSyntaxErrorException: user lacks privilege or object not found: E
 at org.hsqldb.jdbc.JDBCUtil.sqlException(Unknown Source)
 at org.hsqldb.jdbc.JDBCUtil.sqlException(Unknown Source)
 at org.hsqldb.jdbc.JDBCStatement.fetchResult(Unknown Source)
 at org.hsqldb.jdbc.JDBCStatement.executeQuery(Unknown Source)
 at net.ucanaccess.jdbc.UcanaccessStatement.executeQuery(UcanaccessStatement.java:208)
 ... 2 more
Caused by: org.hsqldb.HsqlException: user lacks privilege or object not found: E
 at org.hsqldb.error.Error.error(Unknown Source)
 at org.hsqldb.error.Error.error(Unknown Source)
 at org.hsqldb.QuerySpecification.resolveColumnReferencesForAsterisk(Unknown Source)
 at org.hsqldb.QuerySpecification.resolveReferences(Unknown Source)
 at org.hsqldb.QueryExpression.resolve(Unknown Source)
 at org.hsqldb.ParserDQL.compileCursorSpecification(Unknown Source)
 at org.hsqldb.ParserCommand.compilePart(Unknown Source)
 at org.hsqldb.ParserCommand.compileStatements(Unknown Source)
 at org.hsqldb.Session.executeDirectStatement(Unknown Source)
 at org.hsqldb.Session.execute(Unknown Source)
 ... 5 more
Could not connect to the Database
UCAExc:::4.0.0 user lacks privilege or object not found: E

而如果我运行第二次调用 ResultSet（单行查询），则数据会从 table 正确返回。现在据我所知（除了在第一行中跨越多行）这两个查询是相同的。那么为什么第一个抛出错误呢？我无法想象格式的选择会有所不同，但正如我所说，我知道使用 ucanaccess。

如有任何帮助，我们将不胜感激。提前致谢！

Answer 1

我经常给出的 link 在这里也有效：
How to debug dynamic SQL in VBA

您正在连接一个 SQL 字符串而没有检查它是否正确。

ResultSet rs = test.executeQuery("SELECT e.* "
                               + "FROM Employees e"
                               + "WHERE e.EmployeeNo LIKE 'H%'" 
                               + "ORDER BY e.LastName");

将导致

SELECT e.* FROM Employees eWHERE e.EmployeeNo LIKE 'H%'ORDER BY e.LastName

换行符之间缺少空格。

执行多行查询不适用于 table 别名，而单行查询可以

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