Question

Postgres plpgsql函数：

CREATE OR REPLACE FUNCTION usersList()
RETURNS TABLE(at varchar,name varchar,surname varchar)  AS $$
    BEGIN
        RETURN QUERY SELECT * FROM users;
    END;
$$ LANGUAGE plpgsql;

和java代码

result = Pstatement.executeQuery("Select usersList() ");
while(result.next()) {
    System.out.println(result.getString(("at")));
    System.out.println(result.getString(("name")));
    System.out.println(result.getString(("surname")));
}

Java error sql exception message：

Message: The column name at was not found in this ResultSet.
SQLState: 42703
ErrorCode: 0

如何从函数返回所有表列，然后在java中打印它们？

Answer 1

Postgres plpgsql函数：

CREATE OR REPLACE FUNCTION usersList()
RETURNS TABLE(at varchar,name varchar,surname varchar)  AS $$
    BEGIN
        RETURN QUERY SELECT * FROM users;
    END;
$$ LANGUAGE plpgsql;

和java代码

result = Pstatement.executeQuery("SELECT * FROM usersList() ");
while(result.next()) {
    System.out.println(result.getString(("at")));
    System.out.println(result.getString(("name")));
    System.out.println(result.getString(("surname")));
}

致RealSkeptic＆amp;＆amp;尼克巴恩斯!!!

Answer 2

您可以使用result.getMetaData().getColumnCount()查看检索的列数，然后调用result.getMetaData().getColumnName(x)来检查列的名称（将x替换为列数）。< / p>

从技术上讲，您应该能够像这样编写代码块：

result = Pstatement.executeQuery("Select usersList() ");
String mesites[];
while(result.next()) {
    int columnCount = result.getMetaData().getColumnCount();
    System.out.println("Found:"+columnCount+" columns.");
    for(int i=1; i<=columnCount; i++){
        System.out.println(result.getString(result.getMetaData().getColumnName(i)));
    }
}

然后应该打印出在该结果集中检索的任何列，而不管名称（如果有的话）。

我无法从plpgsql函数中读取java返回的数组

2 个答案: