Question

给出一个ID列表，比如user1，user2，user3;我需要构造一个查询，该查询将返回一个列表，该列表仅包含数据库中存在的列表，例如user1，user2。

我当前的实现如下（无效的SQL语句）：

String queryString = ""
                + "IF EXISTS (SELECT cols... "
                + "FROM table "
                + "WHERE userID "
                + "IN (" + ids + ")";
        if ( ! includeDeleted ) {
            queryString += " AND u.DELETED = 'N'";
        }
        queryString += ") BEGIN "
                + "SELECT cols... " 
                + "FROM table "
                + "WHERE userID "
                + "IN (" + ids + ")"
                ;
        if ( ! includeDeleted ) {
            queryString += " AND u.DELETED = 'N'";
        }
        queryString += " END";

Answer 1

这应该是查询：

select * FROM MYTABLE where USERID IN ('user1', 'user4', 'user3');

这是DEMO。

然后使用参数创建查询的代码：

String[] accountIds = {.... your IDs ...}

StringBuilder query = new StringBuilder();
query.append("FROM table t WHERE t.userID IN (");
    for (int i = 0; i < userIds.length; i++) {
        if (!query.toString().endsWith("(")) {
            query.append(", ");
        }
        query.append("?");
    }
    query.append(")");

    if ( ! includeDeleted ) {
        query.append(" AND t.DELETED = 'N'");
    }

SQL SELECT返回以下列表:(如果id存在，则为cols）

1 个答案: