ucanaccess 中的查询输出不正确

Question

我有一个 accdb 文件。我正在使用 ucanaccess api 从我的 Java 项目连接到它并处理数据。 （我没有 MS Access，我在我的 Java 项目中使用 ucanaccess 作为引用库）。

但是，我遇到了一个奇怪的问题，当我在 SQL 服务器中导入 accdb 文件并运行查询 SELECT B.grd , b.[credit hours] , b.term from [1i-stem dcccd student courses] B where [student id] = '2169095'; 时，我得到以下输出：

但是当我在 ucanaccess 中运行查询时，我得到以下输出：

（在 ucanaccess 命令行输出中有两条额外的记录，grd 为空）。

当我输入 .accdb 文件路径时，我在 ucanaccess 控制台中收到以下消息：

    Please, enter the full path to the access file (.mdb or accdb): C:\\Users\\Tejas\\Desktop\\sample.accdb
log4j:WARN No appenders could be found for logger (com.healthmarketscience.jackcess.impl.DatabaseImpl).
log4j:WARN Please initialize the log4j system properly.
WARNING:External file P:\IE\Warehouse (New 1-27-15)\MVC Data Warehouse.mdb does not exist
WARNING:given file does not exist: P:\IE\Warehouse (New 1-27-15)\MVC Data Warehouse.mdb
WARNING:External file P:\IE\Warehouse (New 1-27-15)\MVC Data Warehouse.mdb does not exist
WARNING:given file does not exist: P:\IE\Warehouse (New 1-27-15)\MVC Data Warehouse.mdb
WARNING:External file P:\IE\Warehouse (New 1-27-15)\MVC Data Warehouse.mdb does not exist
WARNING:given file does not exist: P:\IE\Warehouse (New 1-27-15)\MVC Data Warehouse.mdb
WARNING:External file P:\IE\Warehouse (New 1-27-15)\GPA - Standing.mdb does not exist
WARNING:given file does not exist: P:\IE\Warehouse (New 1-27-15)\GPA - Standing.mdb
WARNING:External file P:\IE\Warehouse (New 1-27-15)\MVC Data Warehouse.mdb does not exist
WARNING:given file does not exist: P:\IE\Warehouse (New 1-27-15)\MVC Data Warehouse.mdb
WARNING:External file P:\IE\Warehouse (New 1-27-15)\MVC Data Warehouse.mdb does not exist
WARNING:given file does not exist: P:\IE\Warehouse (New 1-27-15)\MVC Data Warehouse.mdb
WARNING:External file P:\IE\Warehouse (New 1-27-15)\MVC Data Warehouse.mdb does not exist
WARNING:given file does not exist: P:\IE\Warehouse (New 1-27-15)\MVC Data Warehouse.mdb
WARNING:External file P:\IE\Warehouse (New 1-27-15)\MVC Data Warehouse.mdb does not exist
WARNING:given file does not exist: P:\IE\Warehouse (New 1-27-15)\MVC Data Warehouse.mdb
WARNING:External file P:\IE\Warehouse (New 1-27-15)\MVC Data Warehouse.mdb does not exist
WARNING:given file does not exist: P:\IE\Warehouse (New 1-27-15)\MVC Data Warehouse.mdb
WARNING:Error in the metadata of the table 12i-Fac Info: table's row count in the metadata is 1642 but 1652 records have been found and loaded by UCanAccess. All will work fine, but it's better to repair your database.
WARNING:Error in the metadata of the table 3i-STEM STUDENTS LOAD BY TERM: table's row count in the metadata is 8716 but 4358 records have been found and loaded by UCanAccess. All will work fine, but it's better to repair your database.
Error occured at the first loading attempt of 12i-Faculty Latetst Information
Converted view was :CREATE VIEW "Z_12I-FACULTY LATETST INFORMATION" AS SELECT "STUDENT COURSE"."FAC ID", Last("STUDENT COURSE"."FACULTY LAST NAME") AS "LASTOFFACULTY LAST NAME", Last("STUDENT COURSE"."FACULTY FIRST NAME") AS "LASTOFFACULTY FIRST NAME"
FROM "STUDENT COURSE"
GROUP BY "STUDENT COURSE"."FAC ID"
Error message was :user lacks privilege or object not found: STUDENT COURSE
Loaded Tables:
10i-STEM STUDENT LATEST MAJOR INFORMATION, 12i-Fac Info, 13-F1 students by Term, 14i- Faculty Per Term, 15i- STEM COURSE MASTER, 15i- STEM COURSE MASTER by TERM, 1i-STEM DCCCD STUDENT COURSES, 2i - STEM latest Student Information, 3i-STEM STUDENTS LOAD BY TERM, 4i-STEM STUDENT Latest GPA, 5i-STEM MVC STUDENT COURSE 2014-15AY, 6-Financial AID By Sum of Term Amt, 7-STEM - ACAD YR MASTER, 7-STEM MVC Acad-YR TERM, 8i-STEM STUDENT COURSE STATUS BY TERM, 9-STEM TERM MASTER, Financial AID By Sum of Term Amt, STEM TERM VALUES
Loaded Queries:
2014-15AY STEM STUDENT UNIQ ID AS OF 6-4-15, 2i-STEM UNIQUE STUDENT LATEST TERM
Loaded Indexes:
Primary Key  on 1i-STEM DCCCD STUDENT COURSES Columns: (ID) 
, Primary Key  on 5i-STEM MVC STUDENT COURSE 2014-15AY Columns: (ID) 
, Primary Key  on STEM TERM VALUES Columns: (Term Code) 
, Index on 12i-Fac Info Columns: (FAC ID) 
, Index on 7-STEM - ACAD YR MASTER Columns: (CODE) 
, Index on STEM TERM VALUES Columns: (Term Code) 

Cannot load view MVC Acad_YR - TERM : user lacks privilege or object not found: STUDENT COURSE
Cannot load view 12i-Faculty Latetst Information : user lacks privilege or object not found: STUDENT COURSE
Cannot load view 4i-STEM STUDENTS Latest GPA - 3 : user lacks privilege or object not found: GPA - TERM AND CUMM
Cannot load view Update the Term Master : user lacks privilege or object not found: STUDENT COURSE
Cannot resolve table 5- STEM MVC Course
Cannot resolve table Course
Cannot resolve table First Time in College
Cannot resolve table GPA - Term and Cumm
Cannot resolve table Student
Cannot resolve table Student Course
Cannot resolve table Student Financial Aid
Cannot resolve table Student Load
Cannot resolve table Student Type
UCanAccess>
Copyright (c) 2012 Marco Amadei
UCanAccess version 3.0.1
You are connected!! 
Type quit to exit 

Commands end with ; 

use:   
   export <pathToCsv>;
for exporting into a .csv file the result set from the last executed query

UCanAccess>SELECT B.grd , b.[credit hours] , b.term from  [1i-stem dcccd student courses] B where [student id] = '2169095';
------------------------------
| GRD | Credit Hours | Term | 
------------------------------

| W | 4.0 | 2009FA | 

| F | 3.0 | 2009FA | 

| A | 3.0 | 2009FA | 

| F | 3.0 | 2009FA | 

| F | 3.0 | 2010SP | 

| F | 3.0 | 2010SP | 

| F | 3.0 | 2010SP | 

| C | 4.0 | 2010SP | 

| F | 3.0 | 2010SP | 

| D | 3.0 | 2012S2 | 

| C | 3.0 | 2012S2 | 

| A | 4.0 | 2014FA | 

| A | 4.0 | 2015SP | 

| A | 4.0 | 2015SP | 

| null | 4.0 | 2015FA | 

| null | 4.0 | 2015FA | 


UCanAccess>

还有其他类似的不一致。就像在 SQL Server 中一样，对于特定查询，其中一个列输出是“A”，但在 ucanaccess 中它是“null”。

我该如何解决这个问题？

Answer 1

首先，您使用的是旧的 2.0.9.5 版本，所以如果您使用最新的 3.0.1 并使用 3.0.1 输出作为第一步更新您的问题，那就太好了。 其次，数据库可能已损坏，可以使用 MS Access Compact 和修复工具进行修复。但是，执行以下代码（jackcess）并让我们知道您的发现（程序输出）可能非常有用。

package net.ucanaccess.test;

import java.io.File;
import java.io.IOException;
import java.sql.SQLException;
import java.util.Iterator;

import com.healthmarketscience.jackcess.Database;
import com.healthmarketscience.jackcess.DatabaseBuilder;
import com.healthmarketscience.jackcess.Row;
import com.healthmarketscience.jackcess.Table;


public class Jackcess {
    public static void main(String[] d) throws IOException, SQLException{
        DatabaseBuilder dbd =new DatabaseBuilder(new File("Path to your file"));
        dbd.setAutoSync(false);
        Database db=dbd.open();
        Table t=db.getTable("1i-stem dcccd student courses");
        System.out.println(t);
          Iterator<Row> it=t.iterator();
          while(it.hasNext()){
              System.out.println(it.next());
          }
    }

}