Всъщност persistence.xml при мен изглежда така:

<persistence xmlns="http://xmlns.jcp.org/xml/ns/persistence" version="2.1">
    <persistence-unit name="blog-db">
        <properties>
            <property name="javax.persistence.jdbc.driver" value="com.mysql.cj.jdbc.Driver" />
            <property name="javax.persistence.jdbc.url" value="jdbc:mysql://localhost/blog_db" />
            <property name="javax.persistence.jdbc.user" value="root" />
            <property name="javax.persistence.jdbc.password" value="" />
            <property name="hibernate.connection.characterEncoding" value="utf-8" />
            <property name="hibernate.show_sql" value="false" />
            <property name="hibernate.format_sql" value="true" />
            <property name="hibernate.hbm2ddl.auto" value="create" />
        </properties>
    </persistence-unit>
</persistence>

промених 5-тия ред, но вместо да се оправи ми дава следната грешка:

"C:\Program Files\Java\jdk1.8.0_101\bin\java" -Didea.launcher.port=7534 "-Didea.launcher.bin.path=C:\Program Files (x86)\JetBrains\IntelliJ IDEA 2016.2.1\bin" -Dfile.encoding=UTF-8 -classpath "C:\Program Files\Java\jdk1.8.0_101\jre\lib\charsets.jar;C:\Program Files\Java\jdk1.8.0_101\jre\lib\deploy.jar;C:\Program Files\Java\jdk1.8.0_101\jre\lib\ext\access-bridge-64.jar;C:\Program Files\Java\jdk1.8.0_101\jre\lib\ext\cldrdata.jar;C:\Program Files\Java\jdk1.8.0_101\jre\lib\ext\dnsns.jar;C:\Program Files\Java\jdk1.8.0_101\jre\lib\ext\jaccess.jar;C:\Program Files\Java\jdk1.8.0_101\jre\lib\ext\jfxrt.jar;C:\Program Files\Java\jdk1.8.0_101\jre\lib\ext\localedata.jar;C:\Program Files\Java\jdk1.8.0_101\jre\lib\ext\nashorn.jar;C:\Program Files\Java\jdk1.8.0_101\jre\lib\ext\sunec.jar;C:\Program Files\Java\jdk1.8.0_101\jre\lib\ext\sunjce_provider.jar;C:\Program Files\Java\jdk1.8.0_101\jre\lib\ext\sunmscapi.jar;C:\Program Files\Java\jdk1.8.0_101\jre\lib\ext\sunpkcs11.jar;C:\Program Files\Java\jdk1.8.0_101\jre\lib\ext\zipfs.jar;C:\Program Files\Java\jdk1.8.0_101\jre\lib\javaws.jar;C:\Program Files\Java\jdk1.8.0_101\jre\lib\jce.jar;C:\Program Files\Java\jdk1.8.0_101\jre\lib\jfr.jar;C:\Program Files\Java\jdk1.8.0_101\jre\lib\jfxswt.jar;C:\Program Files\Java\jdk1.8.0_101\jre\lib\jsse.jar;C:\Program Files\Java\jdk1.8.0_101\jre\lib\management-agent.jar;C:\Program Files\Java\jdk1.8.0_101\jre\lib\plugin.jar;C:\Program Files\Java\jdk1.8.0_101\jre\lib\resources.jar;C:\Program Files\Java\jdk1.8.0_101\jre\lib\rt.jar;C:\Users\PC\IdeaProjects\JPA-Example-Exersice\target\classes;C:\Users\PC\.m2\repository\org\hibernate\hibernate-core\5.2.1.Final\hibernate-core-5.2.1.Final.jar;C:\Users\PC\.m2\repository\org\jboss\logging\jboss-logging\3.3.0.Final\jboss-logging-3.3.0.Final.jar;C:\Users\PC\.m2\repository\org\hibernate\javax\persistence\hibernate-jpa-2.1-api\1.0.0.Final\hibernate-jpa-2.1-api-1.0.0.Final.jar;C:\Users\PC\.m2\repository\org\javassist\javassist\3.20.0-GA\javassist-3.20.0-GA.jar;C:\Users\PC\.m2\repository\antlr\antlr\2.7.7\antlr-2.7.7.jar;C:\Users\PC\.m2\repository\org\apache\geronimo\specs\geronimo-jta_1.1_spec\1.1.1\geronimo-jta_1.1_spec-1.1.1.jar;C:\Users\PC\.m2\repository\org\jboss\jandex\2.0.0.Final\jandex-2.0.0.Final.jar;C:\Users\PC\.m2\repository\com\fasterxml\classmate\1.3.0\classmate-1.3.0.jar;C:\Users\PC\.m2\repository\dom4j\dom4j\1.6.1\dom4j-1.6.1.jar;C:\Users\PC\.m2\repository\org\hibernate\common\hibernate-commons-annotations\5.0.1.Final\hibernate-commons-annotations-5.0.1.Final.jar;C:\Users\PC\.m2\repository\javax\enterprise\cdi-api\1.1-PFD\cdi-api-1.1-PFD.jar;C:\Users\PC\.m2\repository\javax\el\el-api\2.2\el-api-2.2.jar;C:\Users\PC\.m2\repository\org\jboss\spec\javax\interceptor\jboss-interceptors-api_1.1_spec\1.0.0.Beta1\jboss-interceptors-api_1.1_spec-1.0.0.Beta1.jar;C:\Users\PC\.m2\repository\javax\annotation\jsr250-api\1.0\jsr250-api-1.0.jar;C:\Users\PC\.m2\repository\javax\inject\javax.inject\1\javax.inject-1.jar;C:\Users\PC\.m2\repository\mysql\mysql-connector-java\6.0.3\mysql-connector-java-6.0.3.jar;C:\Program Files (x86)\JetBrains\IntelliJ IDEA 2016.2.1\lib\idea_rt.jar" com.intellij.rt.execution.application.AppMain Examples
VIII 08, 2016 9:50:54 AM org.hibernate.jpa.internal.util.LogHelper logPersistenceUnitInformation
INFO: HHH000204: Processing PersistenceUnitInfo [
    name: blog-db
    ...]
VIII 08, 2016 9:50:54 AM org.hibernate.Version logVersion
INFO: HHH000412: Hibernate Core {5.2.1.Final}
VIII 08, 2016 9:50:54 AM org.hibernate.cfg.Environment <clinit>
INFO: HHH000206: hibernate.properties not found
VIII 08, 2016 9:50:54 AM org.hibernate.cfg.Environment buildBytecodeProvider
INFO: HHH000021: Bytecode provider name : javassist
VIII 08, 2016 9:50:54 AM org.hibernate.annotations.common.reflection.java.JavaReflectionManager <clinit>
INFO: HCANN000001: Hibernate Commons Annotations {5.0.1.Final}
VIII 08, 2016 9:50:55 AM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure
WARN: HHH10001002: Using Hibernate built-in connection pool (not for production use!)
VIII 08, 2016 9:50:55 AM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator
INFO: HHH10001005: using driver [com.mysql.cj.jdbc.Driver] at URL [jdbc:mysql://localhost/blog_db?createDatabaseIfNotExist=true/>]
VIII 08, 2016 9:50:55 AM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator
INFO: HHH10001001: Connection properties: {user=root, characterEncoding=utf-8}
VIII 08, 2016 9:50:55 AM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator
INFO: HHH10001003: Autocommit mode: false
VIII 08, 2016 9:50:55 AM org.hibernate.engine.jdbc.connections.internal.PooledConnections <init>
INFO: HHH000115: Hibernate connection pool size: 20 (min=1)
Exception in thread "main" org.hibernate.service.spi.ServiceException: Unable to create requested service [org.hibernate.engine.jdbc.env.spi.JdbcEnvironment]
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.createService(AbstractServiceRegistryImpl.java:264)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:228)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:207)
    at org.hibernate.engine.jdbc.internal.JdbcServicesImpl.configure(JdbcServicesImpl.java:51)
    at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.configureService(StandardServiceRegistryImpl.java:94)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:237)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:207)
    at org.hibernate.boot.model.process.spi.MetadataBuildingProcess.handleTypes(MetadataBuildingProcess.java:352)
    at org.hibernate.boot.model.process.spi.MetadataBuildingProcess.complete(MetadataBuildingProcess.java:111)
    at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.metadata(EntityManagerFactoryBuilderImpl.java:857)
    at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:884)
    at org.hibernate.jpa.HibernatePersistenceProvider.createEntityManagerFactory(HibernatePersistenceProvider.java:58)
    at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:55)
    at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:39)
    at Examples.main(Examples.java:12)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at com.intellij.rt.execution.application.AppMain.main(AppMain.java:147)
Caused by: org.hibernate.exception.JDBCConnectionException: Error calling Driver#connect
    at org.hibernate.engine.jdbc.connections.internal.BasicConnectionCreator$1$1.convert(BasicConnectionCreator.java:105)
    at org.hibernate.engine.jdbc.connections.internal.BasicConnectionCreator.convertSqlException(BasicConnectionCreator.java:123)
    at org.hibernate.engine.jdbc.connections.internal.DriverConnectionCreator.makeConnection(DriverConnectionCreator.java:41)
    at org.hibernate.engine.jdbc.connections.internal.BasicConnectionCreator.createConnection(BasicConnectionCreator.java:58)
    at org.hibernate.engine.jdbc.connections.internal.PooledConnections.addConnections(PooledConnections.java:106)
    at org.hibernate.engine.jdbc.connections.internal.PooledConnections.<init>(PooledConnections.java:40)
    at org.hibernate.engine.jdbc.connections.internal.PooledConnections.<init>(PooledConnections.java:19)
    at org.hibernate.engine.jdbc.connections.internal.PooledConnections$Builder.build(PooledConnections.java:138)
    at org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl.buildPool(DriverManagerConnectionProviderImpl.java:110)
    at org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl.configure(DriverManagerConnectionProviderImpl.java:74)
    at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.configureService(StandardServiceRegistryImpl.java:94)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:237)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:207)
    at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.buildJdbcConnectionAccess(JdbcEnvironmentInitiator.java:145)
    at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.initiateService(JdbcEnvironmentInitiator.java:66)
    at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.initiateService(JdbcEnvironmentInitiator.java:35)
    at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.initiateService(StandardServiceRegistryImpl.java:88)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.createService(AbstractServiceRegistryImpl.java:254)
    ... 19 more
Caused by: java.sql.SQLException: The connection property 'createDatabaseIfNotExist' only accepts values of the form: 'true', 'false', 'yes' or 'no'. The value 'true/>' is not in this set.
    at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:695)
    at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:663)
    at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:653)
    at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:638)
    at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:606)
    at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:624)
    at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:620)
    at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:78)
    at com.mysql.cj.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:658)
    at com.mysql.cj.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:352)
    at com.mysql.cj.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:221)
    at org.hibernate.engine.jdbc.connections.internal.DriverConnectionCreator.makeConnection(DriverConnectionCreator.java:38)
    ... 34 more
Caused by: com.mysql.cj.core.exceptions.WrongArgumentException: The connection property 'createDatabaseIfNotExist' only accepts values of the form: 'true', 'false', 'yes' or 'no'. The value 'true/>' is not in this set.
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
    at com.mysql.cj.core.exceptions.ExceptionFactory.createException(ExceptionFactory.java:54)
    at com.mysql.cj.core.exceptions.ExceptionFactory.createException(ExceptionFactory.java:93)
    at com.mysql.cj.core.conf.DefaultPropertySet.initializeProperties(DefaultPropertySet.java:154)
    at com.mysql.cj.jdbc.ConnectionImpl.initializeDriverProperties(ConnectionImpl.java:2360)
    at com.mysql.cj.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:649)
    ... 37 more
Caused by: com.mysql.cj.core.exceptions.CJException: The connection property 'createDatabaseIfNotExist' only accepts values of the form: 'true', 'false', 'yes' or 'no'. The value 'true/>' is not in this set.
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
    at com.mysql.cj.core.exceptions.ExceptionFactory.createException(ExceptionFactory.java:54)
    at com.mysql.cj.core.exceptions.ExceptionFactory.createException(ExceptionFactory.java:73)
    at com.mysql.cj.core.exceptions.ExceptionFactory.createException(ExceptionFactory.java:62)
    at com.mysql.cj.core.conf.AbstractPropertyDefinition.validateAllowableValues(AbstractPropertyDefinition.java:186)
    at com.mysql.cj.core.conf.BooleanPropertyDefinition.parseObject(BooleanPropertyDefinition.java:45)
    at com.mysql.cj.core.conf.BooleanPropertyDefinition.parseObject(BooleanPropertyDefinition.java:29)
    at com.mysql.cj.core.conf.AbstractRuntimeProperty.setFromString(AbstractRuntimeProperty.java:86)
    at com.mysql.cj.core.conf.AbstractRuntimeProperty.initializeFrom(AbstractRuntimeProperty.java:81)
    at com.mysql.cj.core.conf.ModifiableBooleanProperty.initializeFrom(ModifiableBooleanProperty.java:42)
    at com.mysql.cj.core.conf.AbstractRuntimeProperty.initializeFrom(AbstractRuntimeProperty.java:65)
    at com.mysql.cj.core.conf.DefaultPropertySet.initializeProperties(DefaultPropertySet.java:151)
    ... 39 more

Process finished with exit code 1
 

Еми объркал си малко синтаксиса ... подмени съдържанието на персистънса с това

<persistence xmlns="http://xmlns.jcp.org/xml/ns/persistence" version="2.1">
    <persistence-unit name="blog-db">
        <properties>
            <property name="javax.persistence.jdbc.driver" value="com.mysql.cj.jdbc.Driver" />
            <property name="javax.persistence.jdbc.url" value="jdbc:mysql://localhost/blog_db?createDatabaseIfNotExist=true" />
            <property name="javax.persistence.jdbc.user" value="root" />
            <property name="javax.persistence.jdbc.password" value="" />
            <property name="hibernate.connection.characterEncoding" value="utf-8" />
            <property name="hibernate.show_sql" value="false" />
            <property name="hibernate.format_sql" value="true" />
            <property name="hibernate.hbm2ddl.auto" value="create" />
        </properties>
    </persistence-unit>
</persistence>

Ако пак гърми ... Дай някакъв GitHub или нещо да разгледаме кода

И не забравяй кавичките!

Ето това е целият ми код;

https://github.com/KostadinMarov/project

амиии не съм.Но би ли ми казал как по-точно трябва да ги импортирам и къде.Много ще съ ти благодарен!

аз съм създал базата,но не ми излизат юзерите, аз мога да ги създам и тях, но нали целта на цялата лекция е да се създадът таблиците сами?

Защото виждам тази грешка в стактрейса, който си постнал:

Unknown database 'blog_db'

Защо пише blog_db? На едно място видях да пише blog-db с тире, а тук е с подчертавка? Уеднакви го навсякъде и се подсигури, че имаш база с такова име създаде после.

ами абсолютно така е и при скрипта на наков,но го оправих и това но пак не става, Gesh4o добави коментар, но не разбрах какво точно искаше да каже.Може и там да е грешката.