Question

我想从特定数据库中检索所有表名。我尝试了以下代码

try {
        DatabaseMetaData dbmd = connection.getMetaData();
        String[] types = {"TABLE"};
        ResultSet rs = dbmd.getTables(null, null, "%", types);
        while (rs.next()) {
            System.out.println(rs.getString("TABLE_NAME"));
        }
    } catch (SQLException e) {
        e.printStackTrace();
    }

但是它给出了nullpointer异常。

Answer 1

以下示例显示方法conn.getMetaData()将返回预期数据。

public class Main {

    public static void main(String[] args) throws SQLException {
        try (Connection conn = DriverManager.getConnection("jdbc:sqlite:testdata.db");
                Statement stmt = conn.createStatement()) {
            String sql = "CREATE TABLE IF NOT EXISTS TEST_TABLE"
                    + " (ID INT PRIMARY KEY     NOT NULL,"
                    + " NAME           TEXT    NOT NULL, "
                    + " ADDRESS        CHAR(50))";
            stmt.executeUpdate(sql);

            DatabaseMetaData md = conn.getMetaData();
            ResultSet rs = md.getTables(null, null, "%", null);
            while (rs.next()) {
                System.out.printf("table name: %s%n", rs.getString("TABLE_NAME"));
            }
        }
    }
}

产生输出：

table name: TEST_TABLE

Answer 2

尝试以下方法：

DatabaseMetaData md = conn.getMetaData();
ResultSet rs = md.getTables(null, null, "%", null);
while (rs.next()) {
  System.out.println(rs.getString(3));
}

（取自此处：https://stackoverflow.com/a/2780375/1843508）

如何使用jdbc从特定数据库获取所有表名

2 个答案: