无法连接数据库
java.sql.SQLException: [Microsoft][ODBC 驱动程序管理器] 未发现数据源名称并且未指定默认驱动程序
at sun.jdbc.odbc.JdbcOdbc.createSQLException(JdbcOdbc.java:6957)
at sun.jdbc.odbc.JdbcOdbc.standardError(JdbcOdbc.java:7114)
at sun.jdbc.odbc.JdbcOdbc.SQLDriverConnect(JdbcOdbc.java:3073)
at sun.jdbc.odbc.JdbcOdbcConnection.initialize(JdbcOdbcConnection.java:323)
at sun.jdbc.odbc.JdbcOdbcDriver.connect(JdbcOdbcDriver.java:174)
at java.sql.DriverManager.getConnection(DriverManager.java:582)
at java.sql.DriverManager.getConnection(DriverManager.java:185)
at Manage_course.<init>(Manage_course.java:109)
at Manage_course.main(Manage_course.java:274)