Java:如何从ResultSet Select查询提取计数
这个问题在这里之前已经得到了回答,但是发布的解决方案对我来说并不适用。以下是我的代码:Java:如何从ResultSet Select查询提取计数,java,sql,count,resultset,Java,Sql,Count,Resultset,这个问题在这里之前已经得到了回答,但是发布的解决方案对我来说并不适用。以下是我的代码: Statement query = this.conn.createStatement(); ResultSet resultSet = query.executeQuery("Select COUNT(*) FROM Questions AS total"); resultSet.next(); int totalQuestions =
Statement query = this.conn.createStatement();
ResultSet resultSet = query.executeQuery("Select COUNT(*) FROM Questions AS total");
resultSet.next();
int totalQuestions = resultSet.getInt("total");
System.out.println(totalQuestions);
System.exit(1);
resultSet.close();
它只是不断地说找不到列总数。我也尝试过,但没有使用“resultSet.next()”,但问题相同。我也尝试过resultSet.getInt(1),但这也不起作用 您想要的SQL语法是
Select COUNT(*) AS total FROM Questions
或者,您也可以从问题中编写选择COUNT(*)
并使用resultSet.getInt(1)
更改:
Select COUNT(*) FROM Questions AS total
致:
您的SQL查询有点错误。尝试:
ResultSet resultSet = query.executeQuery("Select COUNT(*) AS total FROM Questions");
像这样更改您的查询 SQL语法是
Select COUNT(*) AS total FROM Questions
ResultSet ResultSet=query.executeQuery(“选择COUNT(*)作为问题总数”)代码>您就完成了。。。。
Select COUNT(*) AS total FROM Questions