Java 如何在使用Ebean查询原始SQL时映射结果
使用Ebean创建的Postgres表,我想用手写语句查询这些表:Java 如何在使用Ebean查询原始SQL时映射结果,java,sql,postgresql,ebean,Java,Sql,Postgresql,Ebean,使用Ebean创建的Postgres表,我想用手写语句查询这些表: SELECT r.name, r.value, p.name as param1, a.name as att1, p2.name as param2, a2.name as att2 FROM compatibility c JOIN attribute a ON c.att1_id = a.id JOIN attribute a2 ON c.att2_id
SELECT r.name,
r.value,
p.name as param1,
a.name as att1,
p2.name as param2,
a2.name as att2
FROM compatibility c
JOIN attribute a ON c.att1_id = a.id
JOIN attribute a2 ON c.att2_id = a2.id
JOIN PARAMETER p ON a.parameter_id = p.id
JOIN PARAMETER p2 ON a2.parameter_id = p2.id
JOIN rating r ON c.rating_id = r.id
WHERE p.problem_id = %d
OR p2.problem_id = %d
每个连接的表表示我的一个模型类。
查询执行得很好,但我不知道如何继续:
如何使用Play 2.2执行查询。埃宾呢?
如何将此查询映射到iterable对象?我需要创建一个包含查询中所有字段的模型类,还是可以使用某种HashMap?
如何以安全的方式参数化查询?要执行此查询,需要使用RawSql类。您还必须创建结果将被强制转换到的类 以下是示例性结果类的代码:
import javax.persistence.Entity;
import com.avaje.ebean.annotation.Sql;
@Entity
@Sql
public class Result {
String name;
Integer value;
String param1;
String param2;
String att1;
String att2;
}
以及执行此查询的示例:
String sql
= " SELECT r.name,"
+ " r.value,"
+ " p.name as param1,"
+ " a.name as att1,"
+ " p2.name as param2,"
+ " a2.name as att2"
+ " FROM compatibility c"
+ " JOIN attribute a ON c.att1_id = a.id"
+ " JOIN attribute a2 ON c.att2_id = a2.id"
+ " JOIN PARAMETER p ON a.parameter_id = p.id"
+ " JOIN PARAMETER p2 ON a2.parameter_id = p2.id"
+ " JOIN rating r ON c.rating_id = r.id"
+ " WHERE p.problem_id = %d"
+ " OR p2.problem_id = %d"
RawSql rawSql =
RawSqlBuilder
.parse(sql)
.columnMapping("r.name", "name")
.columnMapping("r.value", "value")
.create();
Query<Result> query = Ebean.find(Result.class);
query.setRawSql(rawSql)
.where().gt("amount", 10);
List<Result> list = query.findList();
stringsql
=“选择r.name,”
+r.价值
+p.name作为参数1
+“a.名称作为附件1,”
+p2.name作为参数2
+“a2.名称作为附件2”
+“来自兼容c”
+“在c.att1_id=a.id上连接属性a”
+“在c.att2_id=a2.id上连接属性a2”
+“在a.PARAMETER_id=p.id上连接参数p”
+“在a2.PARAMETER_id=p2.id上连接参数p2”
+“在c.rating_id=r.id上加入评级r”
+“其中p.problem\u id=%d”
+“或p2。问题\u id=%d”
RawSql RawSql=
RawSqlBuilder
.parse(sql)
.columnMapping(“r.name”、“name”)
.columnMapping(“r.value”、“value”)
.create();
Query=Ebean.find(Result.class);
query.setRawSql(rawSql)
.where().gt(“金额”,10);
List=query.findList();
您可以对实体bean使用自己的sql查询,而无需创建RawSql类。请参阅此链接-