英文:
Requesting two datetimes out of a table, but only getting one
问题
以下是您要翻译的内容：
我正在尝试从数据库中获取两个日期时间值，但每次只能获取其中一个。我的意思是，如果我从查询中删除我获取的列（begintijd），我可以获取另一列（eindtijd）。
con = DriverManager.getConnection("jdbc:mysql://localhost:3306/db", "username", "password");
resultTable = new ArrayList<>();
Statement statement = con.createStatement();
statement.execute(query)
ResultSet result = statement.getResultSet();
ResultSetMetaData resultData = result.getMetaData();
while (result.next()) {
Map<String, Object> row = new HashMap<>();
for (int i = 1; i <= resultData.getColumnCount(); i++) {
String type = resultData.getColumnTypeName(i);
switch (type) {
case "INT":
row.put(resultData.getColumnName(i), result.getInt(i));
break;
case "VARCHAR":
case "CHAR":
case "TEXT":
row.put(resultData.getColumnName(i), result.getString(i));
break;
case "DATETIME":
row.put(resultData.getColumnName(i), new java.util.Date(result.getTimestamp(i).getTime()));
break;
default:
throw new IllegalArgumentException("Data type not supported");
}
i++;
}
resultTable.add(row);
}
这是我的主要部分：
String query = "SELECT begintijd, eindtijd, lesID FROM calendar WHERE lesID = 1";
ArrayList<Map<String, Object>> resultTable = Database.executeStatement(query);
System.out.println(resultTable);
结果是这样的（没有错误）：
[{begintijd=Tue Apr 07 08:30:00 CEST 2020, lesID=1}]
这是我的数据库的截图：
我的java.util.Date实现有问题吗？
英文:
I'm trying to get two datetime values out of a database, but I'm only get one of them at a time. By that I mean that if I remove the column I do get (begintijd) from the query I do get the other column (eindtijd).
con = DriverManager.getConnection("jdbc:mysql://localhost:3306/db", "username", "password");
resultTable = new ArrayList<>();
Statement statement = con.createStatement();
statement.execute(query)
ResultSet result = statement.getResultSet();
ResultSetMetaData resultData = result.getMetaData();
while (result.next()) {
Map<String, Object> row = new HashMap<>();
for (int i = 1; i <= resultData.getColumnCount(); i++) {
String type = resultData.getColumnTypeName(i);
switch (type) {
case "INT":
row.put(resultData.getColumnName(i), result.getInt(i));
break;
case "VARCHAR":
case "CHAR":
case "TEXT":
row.put(resultData.getColumnName(i), result.getString(i));
break;
case "DATETIME":
row.put(resultData.getColumnName(i), new java.util.Date(result.getTimestamp(i).getTime()));
break;
default:
throw new IllegalArgumentException("Data type not supported");
}
i++;
}
resultTable.add(row);
}
This is my main:
String query = "SELECT begintijd, eindtijd, lesID FROM calendar WHERE lesID = 1";
ArrayList<Map<String, Object>> resultTable = Database.executeStatement(query);
System.out.println(resultTable);
As a result I get this (no errors):
[{begintijd=Tue Apr 07 08:30:00 CEST 2020, lesID=1}]
Here's a screenshot of my database:
Is there something wrong with my implementation of java.util.Date, or what?
答案1
得分: 0
所以我很笨。
我使用了一个递增的for循环，然后在每个周期结束时再次增加了索引，从而跳过了偶数列。
英文:
So I'm dumb.
I used an incremental for loop, and then incremented the index again at the end of each cycle, essentially skipping the even columns.
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