我在SQLite数据库中有一些数据。 SQLiteBrowser中的以下查询完全给出了我想要的ResultSet:
With TempTable0 AS (SELECT Source, Date, Value AS Close FROM FinData WHERE Type = 'Close'),
TempTable1 AS (SELECT Source, Date, Value AS Colume FROM FinData WHERE Type = ' Colume')
SELECT DISTINCT TempTable0.Date, Close, Colume FROM TempTable0
JOIN TempTable1 ON TempTable1.Date = TempTable0.Date
现在,我尝试通过简单的executeQuery
- Java方法将单个查询作为单个查询,并在Matrixlike-DataStructure中读取数据:
String sql = "With TempTable0 AS (SELECT Source, Date, Value AS Close FROM FinData WHERE Type = 'Close'), TempTable1 AS (SELECT Source, Date, Value AS Colume FROM FinData WHERE Type = ' Colume') SELECT DISTINCT TempTable0.Date, Close, Colume FROM TempTable0 JOIN TempTable1 ON TempTable1.Date = TempTable0.Date";
Connection Conn = DriverManager.getConnection(SQLCommunication.urlDB);
Statement stmt = Conn.createStatement();
ResultSet rs = stmt.executeQuery(sql);
while (rs.next() ) {
String res = rs.getString("Close");
DataMatrix.get("Close").add(res);
res = rs.getString("Colume");
DataMatrix.get("Colume").add(res);
}
但是,Resultset返回null
。
我怀疑这是因为它无法使用两个依赖的SQLite-Queries,但是,我不知道如何解决这个问题。
我不是SQLite和Java交互的专家,而且我现在真的没有想法了。你有任何吸烟吗? (甚至可能会将这两个语句嵌套在一个中,以便一次性执行它?)
非常感谢!
Wiwi