Hibernate中createQuery与createSQLQuery两者的区别
最近几天在写项目，遇到了一个错：
Struts has detected an unhandled exception:
Messages:
ORA-00933: SQL ???????
could not execute query
could not execute query; SQL [ select count(*) from www.csdn.weibo.domain.Pictures where 1=1 and picture_type='aaa']; nested exception is org.hibernate.exception.SQLGrammarException: could not execute query
File: oracle/jdbc/driver/DatabaseError.java
Line number: 112
Stacktraces
org.springframework.dao.InvalidDataAccessResourceUsageException: could not execute query; SQL [ select count(*) from www.csdn.weibo.domain.Pictures where 1=1 and picture_type='aaa']; nested exception is org.hibernate.exception.SQLGrammarException: could not execute query
在论坛发贴了，看到大家的回复我也改了改，还是没查询不到，于是乎请教老师吧，老师上来就看出问题了，唉唉，并且要我细看hibernate ，createQuery与createSQLQuery两者的区别，所以我先把我的错误展示给大家，然后再看他们的区别。
终于找到问题了 原来是把createQuery和createSQLQuery弄混了，在baseDaoImpl.java 里边我原来写的是
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return
Integer.valueOf((session.createSQLQuery(
" select count(*) from "
+ clazz.getName() +
" "
+ whereSql).uniqueResult() +
""
));
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在jsp中拼接sql语句中写的是
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private
String spliceSql() {
String whereSql =
" where 1=1 "
;
if
(user !=
null
&& user.getId() !=
null
&& !
""
.equals(user.getId())) {
whereSql +=
" and user_id="
+ user.getId() +
" "
;
}
if
(pictures !=
null
&& pictures.getType() !=
null
&& !
""
.equals(pictures.getType())) {
whereSql +=
" and picture_type='"
+ pictures.getType() +
"'"
;
}
return
whereSql;
}
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应该改为这样的，
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return
Integer.valueOf(session.createQuery(
"select count(alias) from "
+ clazz.getName()
+
" as alias "
+whereSql).uniqueResult()
+
""
);
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private
String spliceSql() {
String whereSql =
" where 1=1 "
;
if
(user !=
null
&& user.getId() !=
null
&& !
""
.equals(user.getId())) {
whereSql +=
" and picture.user.id="
+ user.getId() +
" "
;
}
if
(pictures !=
null
&& pictures.getType() !=
null
&& !
""
.equals(pictures.getType())) {
whereSql +=
" and picture.type='"
+ pictures.getType() +
"'"
;
}
return
whereSql;
}
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createQuery与createSQLQuery区别 ：
前者以hibernate生成的Bean为对象装入list返回
后者则是以对象数组进行存储
所以使用createSQLQuery有时候也想以hibernate生成的Bean为对象装入list返回，就不是很方便
突然发现createSQLQuery有这样一个方法可以直接转换对象
Query query = session.createSQLQuery(sql).addEntity(XXXXXXX.class);
XXXXXXX 代表以hibernate生成的Bean的对象，也就是数据表映射出的Bean。
