有没有jar可以在java中更快地执行sql查询

Question

在java中，我使用Prepared语句从数据库中获取值。这里我使用了Index，然后我还绑定了值，我使用了以下查询

Select pname from project where pid="12547";

像这样，我需要从表格项目中提取大约3000个"pname"。执行此操作需要更多的时间。有没有jar可以在java中更快地执行sql查询？

Answer 1

为什么要为这3000个pid执行单独的查询。如果你确信你必须执行那么多查询，你可以切换到最适合你逻辑的任何一个：

select pname from project where pid BETWEEN 1000 and 4000;
select pname from project where pid IN (1000, 1001, ...);
select pname from project where pid > 2000 and pid < 5000;

您可以在where子句中使用这些来修改SQL查询

Operator  Description
=         Equal
<>        Not equal. Note: In some versions of SQL this operator may be written as !=
>         Greater than
<         Less than
>=        Greater than or equal
<=        Less than or equal
BETWEEN   Between an inclusive range
LIKE      Search for a pattern
IN        To specify multiple possible values for a column

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编辑

如果你的价值观是动态的，那么

String selectSQL = "select pname from project where pid IN(?, ?);";
dbConnection = getDBConnection();
preparedStatement = dbConnection.prepareStatement(selectSQL);
preparedStatement.setInt(1, 2000);
preparedStatement.setInt(2, 5000);
// execute select SQL stetement
ResultSet rs = preparedStatement.executeQuery();