Question

尝试使用具有双向关联的实体时遇到查询问题。

我有一个与其他两个实体有某种关系的实体钱包。与实体WalletBranchOffice的关系存在问题。如果我评论这部分代码，一切正常。这是我的实体：

Wallet.java

@Entity
@Table(name="WALLET", schema=SchemasConfig.SCHEMA_NEW)
@Cacheable(true)
@Cache(usage=CacheConcurrencyStrategy.READ_ONLY)
public class Wallet implements Serializable {

private static final long serialVersionUID = 3307006915060155334L;

@Id
@GeneratedValue(strategy = GenerationType.AUTO)
@Column(name="WALLET_ID")
private Integer walletId;
public Integer getWalletId() {
    return walletId;
}

@Column(name="INTERNAL_REFERENCE", nullable=false, length=32)
private String internalReference;
public String getInternalReference() {
    return internalReference;
}

@ManyToOne(fetch=FetchType.EAGER)
@JoinColumn(name="CURRENCY_ID", nullable=false)
private Currency currency;
public Currency getCurrency() {
    return currency;
}

@Column(name = "CACHE_AMOUNT_SUM", nullable = false, precision = 13, scale = 2)
private BigDecimal cacheAmountSum;
public BigDecimal getCacheAmountSum() {
    return cacheAmountSum;
}

@OneToMany(mappedBy="wallet", fetch=FetchType.EAGER)
@MapKeyColumn(name="BRANCH_OFFICE_ID")
@Cache(usage=CacheConcurrencyStrategy.READ_ONLY)
private Map<Integer, WalletBranchOffice> walletBranchOffices;
public Map<Integer, WalletBranchOffice> getWalletBranchOffices() {
    return walletBranchOffices;
}

@OneToMany(mappedBy="wallet", fetch=FetchType.EAGER)
@MapKeyColumn(name="WALLET_PREV_ID")
@Cache(usage=CacheConcurrencyStrategy.READ_ONLY)
/*
 * wallets which must be used before current wallet
 */
private Map<Integer, WalletDependency> walletDependencies;
public Map<Integer, WalletDependency> getWalletDependencies() {
    return walletDependencies;
}

@OneToMany(mappedBy="walletPrev", fetch=FetchType.EAGER)
@MapKeyColumn(name="WALLET_ID")
@Cache(usage=CacheConcurrencyStrategy.READ_ONLY)
/*
 * wallets that can be used after current wallet
 */
private Map<Integer, WalletDependency> dependentWallets;
public Map<Integer, WalletDependency> getDependentWallets() {
    return dependentWallets;
}

@Column(name = "TEXT_KEY")
private String textKey;
public String getTextKey() {
    return textKey;
}

@Override
public int hashCode() {
    final int prime = 31;
    int result = 1;
    result = prime * result
            + ((walletId == null) ? 0 : walletId.hashCode());
    return result;
}

@Override
public boolean equals(Object obj) {
    if (this == obj)
        return true;
    if (obj == null)
        return false;
    if (getClass() != obj.getClass())
        return false;
    Wallet other = (Wallet) obj;
    if (walletId == null) {
        if (other.walletId != null)
            return false;
    } else if (!walletId.equals(other.walletId))
        return false;
    return true;
}
}

WalletBranchOffice.java

@Entity
@Table(name="WALLET_BRANCH_OFFICE", schema=SchemasConfig.SCHEMA_NEW)
@Cacheable
@Cache(usage=CacheConcurrencyStrategy.READ_ONLY)
@Immutable
public class WalletBranchOffice implements Serializable {

private static final long serialVersionUID = 9135909966091486878L;

@Id
@Column(name="WALLET_BRANCH_OFFICE_ID")
private Integer walletBranchOfficeId;
public Integer getWalletBranchOfficeId() {
    return walletBranchOfficeId;
}

@ManyToOne(fetch=FetchType.EAGER)
@JoinColumn(name="WALLET_ID", nullable=false)
private Wallet wallet;
public Wallet getWallet() {
    return wallet;
}


@ManyToOne(fetch=FetchType.EAGER)
@JoinColumn(name="BRANCH_OFFICE_ID", nullable=false)
private BranchOffice branchOffice;
public BranchOffice getBranchOffice() {
    return branchOffice;
}   

@Column(name="CREATE DATETIME")
@Type(type="com.uniqagroup.ims.common.EETDateType$TimestampType")
private Timestamp createDatetime;
public Timestamp getCreateDatetime() {
    return createDatetime;
}
}

这是WalletDependency.java，没有问题。

@Entity
@Table(name="WALLET_DEPENDENCY",schema=SchemasConfig.SCHEMA_NEW)
@Cacheable
@Cache(usage=CacheConcurrencyStrategy.READ_ONLY)
@Immutable
public class WalletDependency implements Serializable {

private static final long serialVersionUID = -6665047739101469610L;

@Id
@Column(name="WALLET_DEPENDENCY_ID")
private Integer walletRequiredId;
public Integer getWalletRequiredId() {
    return walletRequiredId;
}

@ManyToOne(fetch=FetchType.EAGER)
@JoinColumn(name="WALLET_ID", nullable=false)
private Wallet wallet;
public Wallet getWallet() {
    return wallet;
}

@ManyToOne(fetch=FetchType.EAGER)
@JoinColumn(name="WALLET_PREV_ID",nullable=false)
private Wallet walletPrev;
public Wallet getWalletPrev() {
    return walletPrev;
}   
}

我的问题是，如果我执行一个简单的选择查询，如：

List<Wallet> wallets  = em.createQuery("FROM Wallet AS  w",Wallet.class).getResultList();

使用EntityManager，我收到了SQL语法错误：

Caused by: java.sql.SQLSyntaxErrorException: [SQL0199] Keyword AS not expected. Valid tokens: , FROM INTO.
at com.ibm.as400.access.JDError.createSQLExceptionSubClass(JDError.java:852) [jt400-7.9_jdbc4.0.jar:JTOpen 7.9]
at com.ibm.as400.access.JDError.throwSQLException(JDError.java:692) [jt400-7.9_jdbc4.0.jar:JTOpen 7.9]
at com.ibm.as400.access.JDError.throwSQLException(JDError.java:662) [jt400-7.9_jdbc4.0.jar:JTOpen 7.9]
at com.ibm.as400.access.AS400JDBCStatement.commonPrepare(AS400JDBCStatement.java:1763) [jt400-7.9_jdbc4.0.jar:JTOpen 7.9]
at com.ibm.as400.access.AS400JDBCPreparedStatement.<init>(AS400JDBCPreparedStatement.java:354) [jt400-7.9_jdbc4.0.jar:JTOpen 7.9]
at com.ibm.as400.access.AS400JDBCConnection.prepareStatement(AS400JDBCConnection.java:2166) [jt400-7.9_jdbc4.0.jar:JTOpen 7.9]
at com.ibm.as400.access.AS400JDBCConnection.prepareStatement(AS400JDBCConnection.java:2108) [jt400-7.9_jdbc4.0.jar:JTOpen 7.9]
at org.jboss.jca.adapters.jdbc.BaseWrapperManagedConnection.doPrepareStatement(BaseWrapperManagedConnection.java:732)
at org.jboss.jca.adapters.jdbc.BaseWrapperManagedConnection.prepareStatement(BaseWrapperManagedConnection.java:707)
at org.jboss.jca.adapters.jdbc.WrappedConnection.prepareStatement(WrappedConnection.java:404)
at org.hibernate.engine.jdbc.internal.StatementPreparerImpl$5.doPrepare(StatementPreparerImpl.java:161) [hibernate-core-4.2.0.Final-redhat-1.jar:4.2.0.Final-redhat-1]
at org.hibernate.engine.jdbc.internal.StatementPreparerImpl$StatementPreparationTemplate.prepareStatement(StatementPreparerImpl.java:182) [hibernate-core-4.2.0.Final-redhat-1.jar:4.2.0.Final-redhat-1]
... 163 more

Answer 1

无需AS：

List<Wallet> wallets  = em.createQuery("FROM Wallet w",Wallet.class).getResultList();

一些例子：

http://docs.oracle.com/javaee/6/tutorial/doc/bnbrg.html

Answer 2

感谢您的重播！打印出生成的SQL后，我发现了问题。这只是一个愚蠢的技术错误。在WalletBranchOffice实体中将createDatetime属性映射到create_datetime列时缺少“_”符号。 @Column（name =“CREATE DATETIME”）

使用@OneToMany双向关联的Hibernate映射映射

2 个答案: