From ad82958d03b771c36bcfa0a2a8db3b222dac4fb9 Mon Sep 17 00:00:00 2001
From: Martin Goik <goik@hdm-stuttgart.de>
Date: Mon, 11 Apr 2016 22:01:57 +0200
Subject: [PATCH] Correcting entity and table definitions
---
Doc/Sda2/jpa.xml | 293 ++++++++++--------
.../src/main/java/hibintro/v5/User.java | 3 -
.../src/main/java/hibintro/v6/Project.java | 31 +-
.../src/main/java/hibintro/v7/User.java | 15 +-
4 files changed, 173 insertions(+), 169 deletions(-)
diff --git a/Doc/Sda2/jpa.xml b/Doc/Sda2/jpa.xml
index 6d7c532f6..8139bcaa4 100644
--- a/Doc/Sda2/jpa.xml
+++ b/Doc/Sda2/jpa.xml
@@ -1012,19 +1012,20 @@ public class User {
statements containing an attribute <code>selected</code> <coref
linkend="attributeSelected"/>:</para>
- <programlisting language="none">CREATE TABLE User (
- uid VARCHAR(255) NOT NULL PRIMARY KEY,
- cname VARCHAR(255),
- <emphasis role="bold">selected</emphasis> <co xml:id="attributeSelected"/> BIT NOT NULL,
- ) </programlisting>
+ <programlisting language="sql">CREATE TABLE User (
+ uid VARCHAR(255) NOT NULL PRIMARY KEY,
+ cname VARCHAR(255),
+ <emphasis role="bold">selected</emphasis> <co xml:id="attributeSelected"/> BIT NOT NULL,
+) </programlisting>
<para>If we just annotate a Java class with an
<classname>javax.persistence.Entity</classname> Annotation all
properties of the class in question will be mapped. A <xref
linkend="glo_JPA"/> framework of course cannot distinguish between
transient and persistent properties. If we want a property to be
- transient we have to add a
- <classname>javax.persistence.Transient</classname> annotation:</para>
+ transient we have to add a <classname
+ xlink:href="http://docs.oracle.com/javaee/7/api/javax/persistence/Transient.html">javax.persistence.Transient</classname>
+ annotation:</para>
<informaltable border="1">
<colgroup width="6%"/>
@@ -1050,20 +1051,22 @@ public class User {
<tr>
<td valign="top"><emphasis role="bold">SQL</emphasis></td>
- <td><programlisting language="none">CREATE TABLE User (
- uid VARCHAR(255) NOT NULL PRIMARY KEY,
- cname VARCHAR(255)
- ) </programlisting></td>
+ <td><programlisting language="sql">CREATE TABLE User (
+ uid VARCHAR(255) NOT NULL PRIMARY KEY,
+ cname VARCHAR(255)
+) </programlisting></td>
</tr>
</informaltable>
- <para>The <classname>javax.persistence.Transient</classname> annotation
- inhibits the mapping of our property <code>selected</code>.</para>
+ <para>The <classname
+ xlink:href="http://docs.oracle.com/javaee/7/api/javax/persistence/Transient.html">javax.persistence.Transient</classname>
+ annotation inhibits the mapping of our property
+ <code>selected</code>.</para>
<caution>
<para>When loading a <classname>hibintro.v3.User</classname> instance
- from a database the transient property's value is of course entirely
- determined by the constructor.</para>
+ from a database all transient property values are of course entirely
+ determined by the default constructor.</para>
</caution>
</section>
@@ -1079,8 +1082,11 @@ public class User {
<para>The <code>cname</code> property however may be null. Sometimes we
want to ensure the corresponding database attributes to be set, at least
carrying an empty string value. This can be achieved by adding a
- <classname>javax.persistence.Column</classname><code>(nullable =
- false)</code> annotation:</para>
+ <classname
+ xlink:href="http://docs.oracle.com/javaee/7/api/javax/persistence/Column.html">javax.persistence.Column</classname>
+ <option
+ xlink:href="http://docs.oracle.com/javaee/7/api/javax/persistence/Column.html#nullable--">(nullable
+ = false)</option> annotation:</para>
<informaltable border="1">
<colgroup width="6%"/>
@@ -1090,32 +1096,33 @@ public class User {
<tr>
<td valign="top"><emphasis role="bold">Java</emphasis></td>
- <td valign="top"><programlisting language="none">package hibintro.v4;
-
- ...
- @Entity public class User {
-
- String cname;
- <emphasis role="bold">@Column(nullable = false)</emphasis> public String getCname() {
- return cname;
- }
- ...</programlisting></td>
+ <td valign="top"><programlisting language="java">package hibintro.v4;
+ ...
+@Entity public class User {
+ ...
+ String cname;
+ <emphasis role="bold"><classname
+ xlink:href="http://docs.oracle.com/javaee/7/api/javax/persistence/Column.html">@Column</classname>(<option
+ xlink:href="http://docs.oracle.com/javaee/7/api/javax/persistence/Column.html#nullable--">nullable</option> = false)</emphasis> public String getCname() {
+ return cname;
+ }
+ ...</programlisting></td>
</tr>
<tr>
<td valign="top"><emphasis role="bold">SQL</emphasis></td>
- <td><programlisting language="none">CREATE TABLE User (
- uid VARCHAR(255) NOT NULL PRIMARY KEY,
- cname VARCHAR(255) <emphasis role="bold">NOT NULL</emphasis> <co
+ <td><programlisting language="sql">CREATE TABLE User (
+ uid VARCHAR(255) NOT NULL PRIMARY KEY,
+ cname VARCHAR(255) <emphasis role="bold">NOT NULL</emphasis> <co
xml:id="cnameDatabaseNotNull"/>
- )</programlisting></td>
+)</programlisting></td>
</tr>
</informaltable>
<para>This results in a corresponding database constraint <coref
- linkend="cnameDatabaseNotNull"/>. Attempting to store instances with
- null values now fails:</para>
+ linkend="cnameDatabaseNotNull"/>. Attempts to store instances with null
+ values now fail:</para>
<informaltable border="1">
<colgroup width="6%"/>
@@ -1129,39 +1136,28 @@ public class User {
...
public class PersistSingleUser {
- final Transaction transaction = session.beginTransaction();
- {
- final User u = new User("goik", null);
- session.save(u);
- }
- transaction.commit(); ...</programlisting></td>
+ em.getTransaction().begin();
+ {
+ em.persist(new User("goik", "Martin Goik"));
+ }
+ em.getTransaction().commit();</programlisting></td>
</tr>
<tr>
<td valign="top"><emphasis role="bold">Log</emphasis></td>
- <td><programlisting language="none">Hibernate:
- insert
- into
- User
- (cname, uid)
- values
- (?, ?)
- ...
- WARN: SQL Error: 1048, SQLState: 23000
- Feb 13, 2013 9:38:32 PM org.hibernate.engine.jdbc.spi.SqlExceptionHelper logExceptions
- ERROR: Column 'cname' cannot be null
- Exception in thread "main" org.hibernate.exception.ConstraintViolationException: Column 'cname' cannot be null
- ...
- <emphasis role="bold">Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Column 'cname' cannot be null</emphasis>
- ...</programlisting></td>
+ <td><programlisting language="none">Exception in thread "main" javax.persistence.PersistenceException:
+ org.hibernate.PropertyValueException: <emphasis role="bold">not-null property references a null or transient value</emphasis> :
+hibintro.v4.User.cname
+ at org.hibernate.jpa.spi.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1692)
+ ...
+ at hibintro.v4.PersistSingleUser.main(PersistSingleUser.java:22)</programlisting></td>
</tr>
</informaltable>
- <para>The exception is thrown by the <trademark
+ <para>The database constraint violation causes the <trademark
xlink:href="http://www.oracle.com/technetwork/java/javase/jdbc">JDBC</trademark>
- driver as the result of a database constraint violation but not by the
- hibernate framework itself prior to attempting the insert.</para>
+ driver to throw this exception.</para>
</section>
<section xml:id="mappingKeys">
@@ -1169,36 +1165,48 @@ public class User {
<para>Frequently we need more than just a primary key. Starting from
<classname>hibintro.v4.User</classname> we may want to add a property
- <code>uidNumber</code>. This is a common requirement: On UNIX type
- operation systems for example each user does have both a unique login
- name (like <quote>goik</quote>) and a unique numerical value (like
+ <code>uidNumber</code> adding a common requirement: On UNIX type
+ operation systems each user does have both a unique login name (like
+ <quote>goik</quote>) and a unique numerical value (like
<quote>123</quote>). We choose our primary key to be numeric <coref
linkend="uidNumberIsPrimaryKey"/>and the login name to become a second
candidate key <coref linkend="uidIsUnique"/>:</para>
- <programlisting language="none">package hibintro.v5;
- ...
- @Entity
- @Table(uniqueConstraints={@UniqueConstraint(columnNames={"uid"})}) <co
+ <programlisting language="java">package hibintro.v5;
+
+import javax.persistence.Column;
+import javax.persistence.Entity;
+import javax.persistence.Id;
+import javax.persistence.Table;
+import javax.persistence.UniqueConstraint;
+
+@Entity
+@Table(uniqueConstraints={<classname
+ xlink:href="http://docs.oracle.com/javaee/7/api/javax/persistence/UniqueConstraint.html">@UniqueConstraint</classname>(<option
+ xlink:href="http://docs.oracle.com/javaee/7/api/javax/persistence/UniqueConstraint.html#columnNames--">columnNames</option>={"uid"})}) <co
xml:id="uidIsUnique"/>
- public class User {
+public class User {
- int uidNumber;
- @Id <co xml:id="uidNumberIsPrimaryKey"/> public int getUidNumber() {
- return uidNumber;
- }
- public void setUidNumber(int uidNumber) {
- this.uidNumber = uidNumber;
- }
+ int uidNumber;
+ @Id <co xml:id="uidNumberIsPrimaryKey"/>
+ public int getUidNumber() { return uidNumber; }
+ public void setUidNumber(int uidNumber) { this.uidNumber = uidNumber; }
- String uid;
- public String getUid() {
- return uid;
- }
- public void setUid(String uid) {
- this.uid = uid;
- }
- ...</programlisting>
+ String uid;
+
+ /**
+ * @return The user's unique login name e.g. "goik"
+ */
+ @Column(nullable=false)
+ public String getUid() { return uid; }
+
+ /**
+ * @param uid, See {@link #getUid()}.
+ */
+ public void setUid(String uid) { this.uid = uid; }
+
+ ...
+}</programlisting>
<para>Notice the slight difference: The property <code>uid</code> may
need a
@@ -1218,23 +1226,23 @@ public class User {
values but attributes only appearing in UNIQUE declarations may become
<code>NULL</code>.</para>
- <para>The <abbrev
+ <para>The resulting <abbrev
xlink:href="https://en.wikipedia.org/wiki/Data_definition_language">DDL</abbrev>
reads:</para>
<programlisting language="none">CREATE TABLE User (
- uidNumber INT NOT NULL PRIMARY KEY,
- cname VARCHAR(255) NOT NULL,
- uid VARCHAR(255) NOT NULL UNIQUE
- )</programlisting>
+ uidNumber INT NOT NULL PRIMARY KEY,
+ cname VARCHAR(255) NOT NULL,
+ uid VARCHAR(255) NOT NULL UNIQUE
+)</programlisting>
</section>
<section xml:id="sect_ComposedKeys">
<title>Composed keys</title>
- <para>Composed candidate keys are sometimes referred to as business
- keys. The underlying logic defines which objects are considered to be
- identical based on their values.</para>
+ <para>Composed candidate keys are often business keys. The underlying
+ logic defines which objects are considered to be identical based on
+ their values.</para>
<para>As an example, we consider a company having several departments.
Regarding projects he following business rules shall apply:</para>
@@ -1279,37 +1287,41 @@ public class User {
<tr>
<td valign="top"><emphasis role="bold">Java</emphasis></td>
- <td valign="top"><programlisting language="none">package hibintro.v6;
- ...
- @Entity
- @Table(uniqueConstraints={@UniqueConstraint(columnNames={"name", "department"})}) <co
+ <td valign="top"><programlisting language="java">package hibintro.v6;
+ ...
+@Entity
+@Table(uniqueConstraints={<classname
+ xlink:href="http://docs.oracle.com/javaee/7/api/javax/persistence/UniqueConstraint.html">@UniqueConstraint</classname>(columnNames={"name", "department"})}) <co
xml:id="projectBusinessKey"/>
- public class Project {
- int id;
- @Id <co xml:id="projectPrimaryKeyDefinition"/> public int getId() {return id;}
- protected void setId(int id) {this.id = id;}
-
- String name;
- @Column(nullable=false) public String getName() {return name;}
- public void setName(String name) {this.name = name;}
-
- int department;
- @Column(nullable=false)
- public int getDepartment() {return department;}
- public void setDepartment(int department) {this.department = department;}
- ...</programlisting></td>
+public class Project {
+
+ int id;
+ @Id <co xml:id="projectPrimaryKeyDefinition"/>
+ public int getId() { return id; }
+ protected void setId(int id) { this.id = id; }
+
+ String name;
+ @Column(nullable=false)
+ public String getName() { return name; }
+ public void setName(String name) { this.name = name; }
+
+ int department;
+ @Column(nullable=false)
+ public int getDepartment() { return department; }
+ public void setDepartment(int department) { this.department = department; }
+ ...
+}</programlisting></td>
</tr>
<tr>
<td valign="top"><emphasis role="bold">Sql</emphasis></td>
- <td><programlisting language="none">CREATE TABLE Project (
- id int(11) NOT NULL PRIMARY KEY <coref
- linkend="projectPrimaryKeyDefinition"/>,
- department int(11) NOT NULL,
- name varchar(255) NOT NULL,
- UNIQUE KEY name (name,department) <coref linkend="projectBusinessKey"/>
- )</programlisting></td>
+ <td><programlisting language="sql">CREATE TABLE Project (
+ id int(11) NOT NULL PRIMARY KEY <coref linkend="projectPrimaryKeyDefinition"/>,
+ department int(11) NOT NULL,
+ name varchar(255) NOT NULL,
+ UNIQUE KEY name (name,department) <coref linkend="projectBusinessKey"/>
+)</programlisting></td>
</tr>
</informaltable>
@@ -1388,32 +1400,49 @@ public class User {
<tr>
<td valign="top"><emphasis role="bold">Java</emphasis></td>
- <td valign="top"><programlisting language="none">package hibintro.v7;
- ...
- @Entity
- @Table(uniqueConstraints={@UniqueConstraint(columnNames={"uid"})})
- <emphasis role="bold">@org.hibernate.annotations.Table(</emphasis> <co
+ <td valign="top"><programlisting language="java">package hibintro.v7;
+...
+@Entity
+@Table(uniqueConstraints={@UniqueConstraint(name="uidKey", columnNames={"uid"})},
+ <emphasis role="bold">indexes = {<classname
+ xlink:href="http://docs.oracle.com/javaee/7/api/javax/persistence/Index.html">@Index</classname>(<option
+ xlink:href="http://docs.oracle.com/javaee/7/api/javax/persistence/Index.html#name--">name</option> = "byCname", <option
+ xlink:href="http://docs.oracle.com/javaee/7/api/javax/persistence/Index.html#columnList--">columnList</option>="cname", <option
+ xlink:href="http://docs.oracle.com/javaee/7/api/javax/persistence/Index.html#unique--">unique</option> = false)}</emphasis> <co
xml:id="hibernateExtensionIndex"/>
- <emphasis role="bold">appliesTo="User",
- indexes = {@Index(name = "findCname", columnNames = {"cname"})})</emphasis>
- public class User {
- ...
- String cname;
- @Column(nullable = false) public String getCname() { return cname;}
- public void setCname(String cname) {this.cname = cname;}
- ...</programlisting></td>
+)
+public class User {
+
+ int uidNumber;
+ @Id
+ public int getUidNumber() { return uidNumber; }
+ public void setUidNumber(int uidNumber) { this.uidNumber = uidNumber; }
+
+ String uid;
+ /**
+ * @return The user's unique login name e.g. "goik"
+ */
+ @Column(nullable=false)
+ public String getUid() { return uid; }
+
+ /**
+ * @param uid See {@link #getUid()}.
+ */
+ public void setUid(String uid) { this.uid = uid; }
+ ...
+}</programlisting></td>
</tr>
<tr>
<td valign="top"><emphasis role="bold">Sql</emphasis></td>
- <td><programlisting language="none">CREATE TABLE User (
- uidNumber INT NOT NULL PRIMARY KEY,
- cname VARCHAR(255) NOT NULL,
- uid VARCHAR(255) NOT NULL UNIQUE
- );
+ <td><programlisting language="sql">CREATE TABLE User (
+ uidNumber INT NOT NULL PRIMARY KEY,
+ cname VARCHAR(255) NOT NULL,
+ uid VARCHAR(255) NOT NULL UNIQUE
+);
- CREATE INDEX findCname ON User (cname ASC);</programlisting></td>
+CREATE INDEX findCname ON User (cname ASC);</programlisting></td>
</tr>
</informaltable>
</section>
diff --git a/ws/eclipse/HibIntro/src/main/java/hibintro/v5/User.java b/ws/eclipse/HibIntro/src/main/java/hibintro/v5/User.java
index e72106a8b..95a51d846 100644
--- a/ws/eclipse/HibIntro/src/main/java/hibintro/v5/User.java
+++ b/ws/eclipse/HibIntro/src/main/java/hibintro/v5/User.java
@@ -44,9 +44,6 @@ public class User {
*/
public void setCname(String cname) { this.cname = cname; }
- /**
- * Hibernate/JPA require a default constructor
- */
protected User() {}
/**
diff --git a/ws/eclipse/HibIntro/src/main/java/hibintro/v6/Project.java b/ws/eclipse/HibIntro/src/main/java/hibintro/v6/Project.java
index 34bfde630..1ea0b7c33 100644
--- a/ws/eclipse/HibIntro/src/main/java/hibintro/v6/Project.java
+++ b/ws/eclipse/HibIntro/src/main/java/hibintro/v6/Project.java
@@ -14,36 +14,23 @@ import javax.persistence.UniqueConstraint;
public class Project {
int id;
- /**
- * @return The object's immutable database id
- */
+
@Id
- public int getId() {
- return id;
- }
- protected void setId(int id) {
- this.id = id;
- }
+ public int getId() { return id; }
+ protected void setId(int id) { this.id = id; }
String name;
@Column(nullable=false)
- public String getName() {
- return name;
- }
- public void setName(String name) {
- this.name = name;
- }
+ public String getName() { return name; }
+ public void setName(String name) { this.name = name; }
int department;
@Column(nullable=false)
- public int getDepartment() {
- return department;
- }
- public void setDepartment(int department) {
- this.department = department;
- }
+ public int getDepartment() { return department; }
+ public void setDepartment(int department) { this.department = department; }
+
+ protected Project() {}
- public Project() {}
public Project(String name, int department) {
setName(name);
setDepartment(department);
diff --git a/ws/eclipse/HibIntro/src/main/java/hibintro/v7/User.java b/ws/eclipse/HibIntro/src/main/java/hibintro/v7/User.java
index 3ef35d144..6ba8e91d3 100644
--- a/ws/eclipse/HibIntro/src/main/java/hibintro/v7/User.java
+++ b/ws/eclipse/HibIntro/src/main/java/hibintro/v7/User.java
@@ -19,23 +19,18 @@ public class User {
int uidNumber;
@Id
- public int getUidNumber() {
- return uidNumber;
- }
+ public int getUidNumber() { return uidNumber; }
public void setUidNumber(int uidNumber) { this.uidNumber = uidNumber; }
String uid;
-
/**
- *
* @return The user's unique login name e.g. "goik"
*/
@Column(nullable=false)
public String getUid() { return uid; }
/**
- * @param uid
- * See {@link #getUid()}.
+ * @param uid See {@link #getUid()}.
*/
public void setUid(String uid) { this.uid = uid; }
@@ -48,14 +43,10 @@ public class User {
public String getCname() { return cname; }
/**
- * @param cname
- * See {@link #getCname()}.
+ * @param cname See {@link #getCname()}.
*/
public void setCname(String cname) { this.cname = cname; }
- /**
- * Hibernate/JPA require a default constructor
- */
protected User() {}
/**
--
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