如何 INNER JOIN 4 个表？

Question

我必须创建一个将数据库连接到 java gui 的地址簿应用程序。我现在正在研究我的搜索按钮，几乎得到了它，但无法弄清楚如何连接所有四个表。我需要按姓氏搜索，然后我希望它显示该人的所有相关信息。

到目前为止，这就是我所拥有的，它似乎正在工作，但是当我尝试 INNER JOIN emailAddresses 和 phoneNumbers 时，我收到了语法错误。

resultSet =
    statement.executeQuery( "SELECT * FROM names INNER JOIN addresses ON names.personID = addresses.personID WHERE lastName LIKE '%" + last + "%' ");
            resultSet.next();
            jTextField1.setText(resultSet.getString("firstName"));
            jTextField2.setText(resultSet.getString("lastName"));
            jTextField3.setText(resultSet.getString("address1"));
            jTextField4.setText(resultSet.getString("address2"));
            jTextField5.setText(resultSet.getString("city"));
            jTextField6.setText(resultSet.getString("state"));
            jTextField7.setText(resultSet.getString("zipcode"));
            jTextField8.setText(resultSet.getString("phoneNumber"));
            jTextField9.setText(resultSet.getString("emailAddress"));

Answer 1

您需要添加括号并使用* 而不是% 作为通配符。
我还没有测试过，但这应该可以工作：

"SELECT     *
FROM    ((names INNER JOIN addresses ON names.personID = addresses.personID)
                INNER JOIN emailadresses ON names.personID = emailadresses.PersonID)
                INNER JOIN PhoneNumbers ON names.PersonID = PhoneNumbers.PersonID
WHERE   lastName LIKE '*" & last & "*'" 

说它应该有效 - 记得在任何姓氏中转义撇号。
Escaping ' in Access SQL

Answer 2

SELECT * FROM names A
INNER JOIN address B ON A.personID = B.personID
INNER JOIN emailAddress C ON A.personID = C.personID
INNER JOIN phoneNumbers D ON A.personID = D.personID

Answer 3

试试这个 SQL 命令，连接四张表和连接一张表或连接多张表是一样的：

SELECT firstName, lastName, address1, address2, city, state, zipcode, phoneNumber, emailAddress FROM names INNER JOIN addresses ON names.personID = addresses.personID INNER JOIN emailadresses ON names.personID = emailadresses.PersonID INNER JOIN PhoneNumbers ON names.PersonID = PhoneNumbers.PersonID WHERE lastName LIKE '%parameter%'