如何生成动态的“(...)"?通过Spring JdbcTemplate的sql列表? [英] How to generate a dynamic "in (...)" sql list through Spring JdbcTemplate?
问题描述
是否可以通过Jdbc模板在SQL查询中生成任意"in()"列表:
Is it possible to generate arbitrary "in ()" lists in a SQL query through Jdbc template:
示例:
从t中选择*,其中(#)中的c",但是#"可以是仅在运行时才知道的任意值列表.
"select * from t where c in (#)" , However '#' could be an arbitrary list of values only known at runtime.
推荐答案
是的,如果您在命名参数中使用NamedParameterJdbcTemplate
或SimpleJdbcTemplate
,则在Spring中是可能的.列表参数可以设置为java.util.List
:
Yes, it's possible in Spring if you use NamedParameterJdbcTemplate
or SimpleJdbcTemplate
with named parameters. List parameter can be set as a java.util.List
:
List<String> list = new ArrayList<String>();
list.add("A");
list.add("B");
list.add("C");
List<SomeObject> result = simpleJdbcTemplate.query("SELECT * FROM t WHERE c in (:list)",
new RowMapper<SomeObject>() { ... },
Collections.singletonMap("list", list));
在这种情况下,当用?
s替换命名参数时,Spring会根据实际列表的大小在内部创建带有所需占位符数量的SQL查询.
In this case Spring internally creates the SQL query with the required number of placeholders based on the size of the actual list when replacing named parameters with ?
s.
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