Question

我有这样的PreparedStatement：

PreparedStatement st = conn
                    .prepareStatement("Select * from "
                            + "(select Count(*) from uch_otstyp b,prov_uch p "
                            + "where b.\"ID_Poezd\"=?"
                            + "and (b.\"NachKm\"*1000+b.\"NachM\")>? "
                            + "and (b.\"NachKm\"*1000+b.\"NachM\")<=? "
                            + "and b.\"ID_Poezd\"=p.\"ID_Poezd\" "
                            + "and b.\"ID_Uch\"=p.\"ID_Uch\" "
                            + "and p.\"MES\"=? "
                            + "and p.\"GOD\"=? "
                            + "and p.\"Nput\"=? "
                            + "and b.\"Kod_Otstup\"=? "
                            + "and b.\"DEPTH\"<1),"
                            + ""
                            + "(select Count(*) from uch_otstyp b,prov_uch p "
                            + "where b.\"ID_Poezd\"=?"
                            + "and (b.\"NachKm\"*1000+b.\"NachM\")>? "
                            + "and (b.\"NachKm\"*1000+b.\"NachM\")<=? "
                            + "and b.\"ID_Poezd\"=p.\"ID_Poezd\" "
                            + "and b.\"ID_Uch\"=p.\"ID_Uch\" "
                            + "and p.\"MES\"=? "
                            + "and p.\"GOD\"=? "
                            + "and p.\"Nput\"=? "
                            + "and b.\"Kod_Otstup\"=? "
                            + "and b.\"DEPTH\">=1)"
                            + "and b.\"DEPTH\"<2)");

每个子查询的参数值都是相同的。如何仅为一个子查询设置参数并自动填充另一个子查询的参数（不是每个子查询）？

Answer 1

您可以使用命名参数，这样当参数在查询中多次出现时，您只需指定一次。 JDBC不支持命名参数，但您可以编写代码以在SQL字符串中查找参数名称，并确定它们出现的顺序，以便可以将参数添加到PreparedStatement。 Spring-Jdbc使用NamedParameterJdbcTemplate here's an example为您完成此操作。这是核心弹簧，实现参数重组的包是org.springframework.jdbc.core.namedparam。

在PreparedStatement中设置相同子查询的参数

1 个答案: