我用 postgresql 创建了一个数据库,我想连接并显示该数据库。
public Connect(){
try {
Class.forName("org.postgresql.Driver");
} catch (ClassNotFoundException e) {
System.err.println("ClassNotFoundException: Postgres Server JDBC");
}
try {
conn = DriverManager.getConnection("jdbc:postgresql://localhost:5432/postgres","postgres","postgrespassword");
System.out.println("Connection successful.");
sql = "select * from mytable";
stmt = conn.createStatement();
rs = stmt.executeQuery(sql);
md = rs.getMetaData();
columns = md.getColumnCount();
for (int i = 1; i <= columns; ++i){
columnNames.addElement(md.getCatalogName(i));
}
while (rs.next()){
Vector row = new Vector(columns);
for(int i = 0; i <= columns; ++i){
row.addElement(rs.getObject(i));
}
data.addElement(row);
}
rs.close();
stmt.close();
} catch (SQLException e){
System.err.println("SQLException");
}
JTable table = new JTable(data, columnNames)
{
public Class getColumnClass(int column)
{
for (int row = 0; row < getRowCount(); row++)
{
Object o = getValueAt(row, column);
if (o != null)
{
return o.getClass();
}
}
return Object.class;
}
};
JScrollPane scrollPane = new JScrollPane( table );
getContentPane().add( scrollPane );
JPanel buttonPanel = new JPanel();
getContentPane().add( buttonPanel, BorderLayout.SOUTH );
}
public void closeConnection() throws SQLException {
try {
conn.close();
System.out.println("Connection close.");
} catch (SQLException e) {
System.err.println("SQLException");
}
}
public void displayDatabase(){
}
}
我得到以下异常:
org.postgresql.util.PSQLException: ERROR: syntax error at or near "mytable"
Position: 15
at org.postgresql.core.v3.QueryExecutorImpl.receiveErrorResponse(QueryExecutorImpl.java:2157)
at org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:1886)
at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:255)
at org.postgresql.jdbc2.AbstractJdbc2Statement.execute(AbstractJdbc2Statement.java:555)
at org.postgresql.jdbc2.AbstractJdbc2Statement.executeWithFlags(AbstractJdbc2Statement.java:403)
at org.postgresql.jdbc2.AbstractJdbc2Statement.executeQuery(AbstractJdbc2Statement.java:283)
at hu.aycm.Connect.<init>(Connect.java:37)
at hu.aycm.Main.main(Main.java:8)
我怎么解决这个问题?有人能帮我吗?谢谢