【发布时间】：2016-08-23 00:40:18
【问题描述】：
当我尝试使用以下代码从 Oracle 数据库中读取数据时，我遇到了异常
ResultSet res=stmt.executeQuery("select * from food");
但是当我直接在命令提示符中使用此命令时，此表实际上存在于我的数据库中正确。所以请有人解释为什么会这样。
java.sql.SQLSyntaxErrorException: ORA-00942: table or view does not exist
at oracle.jdbc.driver.T4CTTIoer.processError(T4CTTIoer.java:440)
at oracle.jdbc.driver.T4CTTIoer.processError(T4CTTIoer.java:396)
at oracle.jdbc.driver.T4C8Oall.processError(T4C8Oall.java:837)
at oracle.jdbc.driver.T4CTTIfun.receive(T4CTTIfun.java:445)
at oracle.jdbc.driver.T4CTTIfun.doRPC(T4CTTIfun.java:191)
at oracle.jdbc.driver.T4C8Oall.doOALL(T4C8Oall.java:523)
at oracle.jdbc.driver.T4CStatement.doOall8(T4CStatement.java:193)
at oracle.jdbc.driver.T4CStatement.executeForDescribe(T4CStatement.java:852)
at oracle.jdbc.driver.OracleStatement.executeMaybeDescribe(OracleStatement.java:1153)
at oracle.jdbc.driver.OracleStatement.doExecuteWithTimeout(OracleStatement.java:1275)
at oracle.jdbc.driver.OracleStatement.executeQuery(OracleStatement.java:1477)
at oracle.jdbc.driver.OracleStatementWrapper.executeQuery(OracleStatementWrapper.java:392)
at connecttooracle.ConnectOracle.main(ConnectOracle.java:67)
我正在通过 Toad 访问食物表中的数据。那为什么我在java中得到这个错误？
我的完整代码是：
public class ConnectOracle {
public static void main(String[] args) {
String driver = "oracle.jdbc.driver.OracleDriver"; //
String serverName = "10.11.201.84";
String portNumber = "1521";
String db = "XE";
String url = "jdbc:oracle:thin:@" + serverName + ":" + portNumber + ":"
+ db; // connectOracle is the data
// source name
String user = "ORAP"; // username of oracle database
String pwd = "ORAP"; // password of oracle database
Connection con = null;
ServerSocket serverSocket = null;
Socket socket = null;
DataInputStream dataInputStream = null;
DataOutputStream dataOutputStream = null;
try {
Class.forName(driver);// for loading the jdbc driver
System.out.println("JDBC Driver loaded");
con = DriverManager.getConnection(url, user, pwd);// for
// establishing
// connection
// with database
Statement stmt = (Statement) con.createStatement();
serverSocket = new ServerSocket(8888);
System.out.println("Listening :8888");
while (true) {
try {
socket = serverSocket.accept();
System.out.println("Connection Created");
dataInputStream = new DataInputStream(
socket.getInputStream());
dataOutputStream = new DataOutputStream(
socket.getOutputStream());
System.out.println("ip: " + socket.getInetAddress());
// System.out.println("message: " +
// dataInputStream.readUTF());
ResultSet res=stmt.executeQuery("select * from food");
while(res.next()){
System.out.println(res.getString(1));
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
if (dataInputStream != null) {
try {
dataInputStream.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
if (dataOutputStream != null) {
try {
dataOutputStream.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
【问题讨论】：
-
如果您的数据库中存在表，请检查您的应用程序中的数据库连接
-
尝试在你的表
food之前添加你的数据库架构。 -
如何添加数据库架构？
-
你检查过你的数据库连接信息吗？！也许你有错误的信息要连接，或者你有多个连接，例如一个到 oracle 的连接和另一个到 mysql 的连接！
-
如何检查？