dialect

How to get Hibernate dialect during runtime

由 丶灬走出姿态 提交于 2020-01-24 02:29:06
问题 In my application, I use Hibernate with SQL Server database, so I set <property name="hibernate.dialect" value="org.hibernate.dialect.SQLServerDialect"> in my persistence.xml. In some case, I want to sort records with NULL include, I use keyword NULLS FIRST. Because it is not supported by default by CriteriaQuery/CriteriaBuilder in Hibernate, then I use Interceptor to modify the native query. The problem is, keyword NULLS FIRST is not supported in SQL Server, so I use keyword: case when

Registering a SQL function with JPA and Hibernate

由 此生再无相见时 提交于 2020-01-19 16:23:36
问题 I would like to know what's the best way to register a custom SQL function with JPA/Hibernate . Do I have to go through extending the MysqlInnodb dialect or is there a better way? Can anyone please provide code samples and pointers to relevant documentation? 回答1: Yes extending the dialect is a good way of registering custom SQL function. Add something like this in your Dialect classes constructor. registerFunction("current_timestamp", new NoArgSQLFunction(Hibernate.TIMESTAMP) );

Can I use SQL functions in NHibernate QueryOver?

由 不羁的心 提交于 2020-01-12 14:12:31
问题 I have been searching the internet and can't find an example on how to use the queryover of nhibernate 3.0 For example I would like to use the string functions on the where clause of the queryover ex: var item = Query.Where(x => x.Name.ToLower() == name.ToLower()).FirstOrDefault(); But this doesn't work, because nhibernate can't understand the ToLower, so how can extend the dialect in a way that this becomes possible? 回答1: session.QueryOver<Foo>() .Where(Restrictions.Eq( Projections

Questions about Dapper SQL queries and parameters with PostgreSQL

由 天涯浪子 提交于 2020-01-02 08:34:42
问题 I´m currently learning about Dapper. I have searched a lot here and other places (including this) and I could not find concrete answers to my doubts: ¿Does Dapper use a generic SQL dialect or it's specific for DB engine? I mean, it uses the SQL syntax expected in the underlaying database engine? At first and after reading over a dozen of examples I thought that the SQL queries where generic, but now trying on PostgresSQL ODBC I have encountered problems with syntax and parameters. Using this

How to get current c dialect in gcc?

由 為{幸葍}努か 提交于 2019-12-24 05:27:13
问题 Newbie in C programming. In gcc -std sets the C standard that compiles, e.g. gcc -std=c99 . It's possible to know which C standard is currently set? 回答1: You can use this program to print the default: #include <stdio.h> int main() { #ifdef __STRICT_ANSI__ printf("c"); #else printf("gnu"); #endif #ifdef __STDC_VERSION__ #if __STDC_VERSION__ == 199901L puts("99"); #elif __STDC_VERSION__ == 201112L puts("11"); #else puts("(unknown)"); #endif #else puts("90"); #endif return 0; } 回答2: There are

optimise Hibernate Sequence ID generation

由 眉间皱痕 提交于 2019-12-23 10:27:35
问题 I'm facing some performance issues while trying to connect Hibernate with SAP HANA In-Memory database, which has no support for AUTO_INCREMENT (http://scn.sap.com/thread/3238906). So I have set Hibernate to use sequences for ID generation. @GeneratedValue(strategy=GenerationType.SEQUENCE, generator="myseq") @SequenceGenerator(name="myseq",sequenceName="MY_SEQ",allocationSize=1) But when I insert big number of records (e.g., 40000), Hibernate first generates IDs. It looks like: DEBUG Thread-1

Difference : hibernate with dialect and without dialect

由 一个人想着一个人 提交于 2019-12-23 04:49:16
问题 I am using hibernate with Oracle database and there is one configuration for dialect, I understood that dialect is used to generate native sql. But I checked the output of generated queries on screen with dialect and without dialect, both seems to same, then what is the use of dialect? can somebody give an code example where in we can rectify this? 回答1: What version of hibernate are you using ? Since version 3.2, hibernate is able to determine dialect automatically. If it detect the right one

Hibernate mysql innodb

由 你说的曾经没有我的故事 提交于 2019-12-22 01:36:13
问题 I wanted to force hibernate to use innodb. So, i changed the "hibernate.dialect" in order to have innodb, but i can connect to mysql, but when i do some transactions i have the following error: org.springframework.transaction.TransactionSystemException: Could not commit JPA transaction; nested exception is javax.persistence.RollbackException: Transaction marked as rol lbackOnly at org.springframework.orm.jpa.JpaTransactionManager.doCommit(JpaTransactionManager.java:465) at org.springframework

Can different GCC dialects be linked together?

由 自闭症网瘾萝莉.ら 提交于 2019-12-17 09:51:41
问题 I know that in principle this is probably undefined behaviour, but in the interest of dealing with a large project, here's my question about GCC: Suppose I compile one transation unit with gcc -std=c++98 , and another with -std=c++11 , using the exact same compiler installation. Is there any sort of guarantee that I can link the two object files and obtain a well-defined program? As far as I can tell, the potential problems can only come from different views of the library headers due to

Hibernate Dialect.数据库方言问题

由 ☆樱花仙子☆ 提交于 2019-12-14 11:38:02
【推荐】2019 Java 开发者跳槽指南.pdf(吐血整理) >>> 由于hibernate映射到对应的数据库字段类型存在的问题，比如大字段等 1.改造默认方言设置，继承特定数据库的方言基类 package selleck.util; import java.sql.Types; import org.hibernate.Hibernate; import org.hibernate.dialect.MySQL5Dialect; public class MySQL5Dialects extends MySQL5Dialect{ public MySQL5Dialects() { super(); registerHibernateType(Types.DECIMAL, Hibernate.BIG_DECIMAL.getName()); registerHibernateType(-1, Hibernate.STRING.getName()); } } 2.修改Hibernate方言默认配置文件 hibernate.dialect= selleck.util.MySQL5Dialects 来源： oschina 链接： https://my.oschina.net/u/938910/blog/106625
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